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Community S-series Installation manual
S-Series
Portable Linear-Response
Loudspeaker Systems
Operation Manual
EC STATEMENT OF CONFORMITY
This document confirms that the range of products of Community Professional Loudspeakers bearing
the CE label meet all of the requirements in the EMC directive 89/336/EEC laid down by the Member
States Council for adjustment of legal requirements. Furthermore, the products comply with the rules
and regulations referring to the electromagnetic compatibility of devices from 30-August-1995.
The Community Professional Loudspeaker products bearing the CE label comply with the following
harmonized or national standards:
DIN EN 55013:08-1991
DIN EN 55020:05-1995
DIN EN 55082-1:03-1993
The authorized declaration and compatibility certification resides with the manufacturer and can be
viewed upon request. The responsible manufacturer is the company:
Community Light & Sound
333 East 5th Street
Chester, PA 19013
USA
TEL: 1-610 876-3400
FAX: 1-610 874-0190
Chester, PA USA February 2007
Community S-Series - Operation and Installation Manual - Page 2
WELCOME TO COMMUNITY!
Since 1968, Community has been designing and building innovative loudspeaker products for the
worldwide sound reinforcement industry. Founded by Bruce Howze, who remains the principal
designer to this day, the company has achieved numerous ‘firsts’ in technology breakthroughs. Some
of these include:
First - fiberglass composite loaded midrange horn for touring systems – the LMF.
First - large-scale fiberglass horns used on Elvis Presley’s 1971 tour.
First - testing and documentation of loudspeakers in a free field acoustical
environment.
First - to publish coverage patterns of its loudspeakers, setting the industry standard.
First - mid-range compression driver, the M4.
First - carbon fiber diaphragm compression driver.
First - passive loudspeakers with internal multi-band, multi-level processing.
First - Ferrofluid-cooled professional cone drivers.
First - HF compression driver diaphragm without an outer suspension – the VHF100.
Community’s philosophy is to build products that are uncompromised in sound quality, reliability,
durability and flexibility, all at a fair price. We provide comprehensive technical support and we stand
behind every product we manufacture. We pledge to do our best to insure that you are satisfied with
your Community purchase!
Community Professional Loudspeakers
333 East Fifth Street
Chester, PA 19013 USA
TEL: 1-(610) 876-3400
FAX: 1-(610) 874-0190
©2007 All Rights Reserved
Community S-Series - Operation and Installation Manual - Page 3
TABLE OF CONTENTS
TABLE OF FIGURES ............................................................................................... 5
IMPORTANT SAFETY INFORMATION .............................................................................. 5
C-TIPS ............................................................................................................ 6
PRECAUTIONS & SAFETY CONSIDERATIONS .................................................................... 6
S-SERIES OPERATION MANUAL
INTRODUCTION.................................................................................................... 7
S-SERIES FEATURES AND TECHNOLOGY ....................................................................... 7
UNPACKING AND INSPECTION ................................................................................... 8
S-Series Specifications .......................................................................................... 9
GETTING ACQUAINTED ..........................................................................................10
Physical Features Of S-Series Full-Range Models .................................................... 11
Physical Features Of S-Series Subwoofers .............................................................. 13
GENERAL DESCRIPTION .........................................................................................14
DYNA-TECH DRIVER PROTECTION SYSTEM ....................................................................14
HIGH-FREQUENCY PRESENCE SWITCH .........................................................................15
SELECTABLE HIGH-PASS OUTPUT ON SUBWOOFERS .........................................................16
COOL-COIL™ TECHNOLOGY ....................................................................................18
OPERATING IN PASSIVE OR BI-AMPED MODE ................................................................18
HIGH-PASS FILTERS ............................................................................................19
CHOOSING ACTIVE CROSSOVERS ..............................................................................19
USING PROTECTIVE LIMITERS ..................................................................................20
CONNECTING THE AMPLIFIER TO THE LOUDSPEAKER ........................................................22
S-SERIES APPLICATIONS .......................................................................................32
POSITIONING SUBWOOFERS ....................................................................................33
SYSTEM EQUALIZATION .........................................................................................37
RIGGING AND MOUNTING S-SERIES ENCLOSURES ...........................................................40
S-SERIES RIGGING AND MOUNTING HARDWARE .............................................................47
1. Seat Track Kit: STKIT ..................................................................................... 47
2. Vertical Fly Kit: VFKIT...................................................................................... 49
AVAILABLE ACCESSORIES .......................................................................................54
SERVICING S-SERIES LOUDSPEAKERS .........................................................................55
TROUBLESHOOTING GUIDE .....................................................................................55
REPLACEMENT PARTS ............................................................................................57
SUMMING THINGS UP ...........................................................................................57
WARRANTY INFORMATION AND SERVICE ......................................................................58
Notice:
Every effort was made to insure that the information contained in this manual
was complete and accurate at the time of printing. However, due to ongoing technical
advances, changes or modifications may have occurred that are not covered in this manual.
Community S-Series - Operation and Installation Manual - Page 4
TABLE OF FIGURES
Following is a list of figures found in this manual:
Figure
Title
Page
1
Physical Features of Typical S-Series Full-Range Models
10
2
Physical Features of Typical S-Series Subwoofers
12
3
Graph Depicting Frequency Response of MUSIC / VOICE Presence Switch
16
4
Graph Depicting Response of HIGH-PASS / FLAT Switch
17
5
Community’s Cool-Coil™ Heat Evacuation System
18
6
S-Series Full-Range Input Panel
22
7
S-Series Subwoofer Input Panel
25
8
Single Amp Connections
26
9
Bi-amp Connections
26
10
Effect of Clipping on a Sinewave
30
11
Effect of Boundary Surfaces on Power Output
34
12
Load Angles
43
13
Never Reeve Cables!
43
14
Never Reeve Cables!
45
15
STKIT Assembly of S-Series Enclosure with four Seat Track Channels and
M10 Hardware
49
16
VFKIT Vertical Fly Kit Assembly
50
17
Never Reeve Cables!
52
18
Rigging Three Enclosures with the VFKIT
52
19
Rigging Four Enclosures with the VFKIT
53
IMPORTANT SAFETY INFORMATION
Always follow these basic safety precautions when using or installing S-Series loudspeakers
and accessories:
1.
2.
3.
4.
5.
Read these instructions.
Keep these instructions.
Heed all warnings.
Follow all instructions, particularly those pertaining to rigging, mounting,
hanging and electrical connections.
Only use accessories that are specified and approved by the manufacturer.
The terms CAUTION, WARNING, and DANGER are used throughout this manual to alert
the reader to important safety considerations. If you have any questions or do not
understand the meaning of these terms, do not proceed with installation. Contact your
local dealer, distributor, or call Community directly for assistance. These terms are defined
below:
CAUTION: describes an operating condition or user action that may expose the equipment
or user to potential damage or danger.
WARNING: describes an operating condition or user action that will likely cause damage to
the equipment or injury to the user or to others in the vicinity.
DANGER: describes an operating condition or user action that will immediately damage the
equipment and/or be extremely dangerous or life threatening to the user or to others in the
vicinity.
Community S-Series - Operation and Installation Manual - Page 5
C-TIPS
Occasionally, in this manual, you’ll come across some useful tips that are intended to help
you get the most from your use of S-Series loudspeakers in portable applications and fixed
installations. We call these C-TIPS (short for COMMUNITY-TIPS or COOL-TIPS…we’ll let
you decide!). These tips originate from Community staff members as well as from installers
and end users. We welcome any C-TIPS that you may want to share with us, and we’ll
acknowledge you as the source if we print them in future user’s manuals.
PRECAUTIONS & SAFETY CONSIDERATIONS
English
The loudspeakers described in this manual are designed and intended to be ‘flown’ or
suspended for maximum acoustical performance using a variety of rigging hardware,
means, and methods. It is essential that all installation work involving the suspension of
these loudspeaker products be performed by competent, knowledgeable persons who
understand safe rigging practices. Severe injury and/or loss of life may occur if these
products are improperly installed. Please read the section on rigging for additional
information.
Français
Les haut-parleurs décrits dans ce manuel sont conçus et sont projetés pour être ‘volé’ ou
suspendu pour l'exécution acoustique maximum utilisant une assortiment d'équiper
matériel, les moyens, et les méthodes. C'est essentiel que tout travail d'installation ait
impliqué la suspension de ces produits d'haut-parleur est exécutée par les personnes
compétentes et entraînées qui comprennent équiper les pratiques sûres. La perte sévère
de et/ou de blessure de vie peut arriver si ces produits sont incorrectement installés. S'il
vous plaît lire la section d'équiper pour l'information supplémentaire.
Deutsch
Die Lautsprecher, die in diesem Handbuch beschrieben werden, sind entworfen und sind zu
sein ‘geflogen' vorgehabt oder sind für maximale hörbare Leistung verschiedene
Manipulierenhardware, Mittel, und Methoden suspendiert benutzend. Es ist wesentlich,
dass alle Installationarbeit, die die Aufhängung von diesen Lautsprechernprodukten
verwickelt, von fähigen, ausgebildeten Personen durchgeführt werde, die sichere
Manipulierenpraxis verstehen. Schwere Verletzung bzw. Verlust des Lebens können
stattfinden, wenn diese Produkte unrichtig installiert sind. Bitte lesen Sie den Abschnitt
über Manipulieren für zusätzliche Informationen.
Italiano
Gli altoparlanti descritti in questo manuale sono disegnati e sono intesi essere ‘volato' o
sospeso per la prestazione massima acustica usando una varietà di attrezzare di hardware,
i mezzi, ed i metodi. È essenziale che tutta il lavoro di installazione coinvolgendo la
sospensione di questi prodotti di altoparlante è eseguita da dalle persone competenti,
addestrate che capisce le pratiche di attrezzare di cassaforte. La lesione severe e/o la
perdita di vita possono accadere se questi prodotti sono erratamente installati. Per favore
di leggere la sezione di attrezzare per le ulteriori informazioni.
Español
Los altavoces descritos en este manual se diseñan y son pensados ser ‘volado' o suspendido
para el desempeño acústico máximo que utiliza una variedad de aparejar hardware, de
medios, y de los métodos. Es esencial que todo trabajo de la instalación que implique la
suspensión de estos productos del altavoz sea realizado por personas competentes y
entrenada que entienden aparejar seguro las prácticas. La herida y/o la pérdida severas de
la vida pueden ocurrir si estos productos se instalan impropiamente. Lea por favor la
sección a aparejar para la información adicional.
Community S-Series - Operation and Installation Manual - Page 6
S-SERIES OPERATION MANUAL
INTRODUCTION
Thank you for selecting Community’s S-Series. S-Series is a family of affordable, linearresponse loudspeakers designed for use in applications requiring controlled coverage
patterns, high-impact power response, with clear and intelligible sonic output. All models
are designed with portability in mind, but they are equally effective in permanent or semipermanent installations.
The S-Series family of products is well suited for use in nightclubs, cafes, discotheques,
houses of worship, auditoriums, meeting rooms, theatres, outdoor concerts, and most
anywhere else that people gather to enjoy music and hear the spoken word.
S-Series loudspeakers are flexible, easy to set up and use, and most importantly they
provide superb sound quality.
This Operation Manual is intended to help you use S-Series loudspeakers effectively and
safely. It provides useful information to assist you in obtaining the best performance,
sound quality, and reliability from your S-Series products.
We’ve provided several easy-to-understand diagrams to enable you to operate your SSeries loudspeakers immediately if required; however, we recommend that you read the
entire manual to insure that your use of S-Series for shows, events, and installations meet
the highest possible standards.
S-SERIES FEATURES AND TECHNOLOGY
S-Series loudspeakers offer numerous features and advances in technology that provide
superb sound and long-term reliability. Some of these include:
•
Sophisticated internal crossover networks for reduced off-axis lobing and consistent
coverage throughout the crossover region.
•
Selectable crossover modes (bi-amped or passive single-amped).
•
Carbon Ring Cone Technology; used on all full-range low-frequency drivers for
reduced distortion, enhanced transient response, and 30% greater cone area than
conventional cone drivers (patent pending).
•
Ferrofluid-cooled high-frequency and mid-frequency drivers for improved heat
conductance and dramatically reduced distortion through viscous damping of driver
resonant modes.
•
Music / Speech PRESENCE Switch re-voices the loudspeaker’s tonal balance for
increased articulation in the vocal range.
•
Powerful 1-inch-throat high-frequency compression drivers offer extended high-end
response, smooth output, and lower distortion than larger format drivers.
•
Non-metallic high-frequency diaphragms provide a further reduction in distortion
by eliminating the mechanical resonance normally associated with brittle metallic
materials.
•
Geometrically correct, hand-laid fiberglass mid and high-frequency waveguides.
•
Community’s patented Cool-CoilTM heat evacuation technology minimizes cone
driver power compression and ensures long-term reliability (used in subwoofers).
Community S-Series - Operation and Installation Manual - Page 7
•
DYNA-TECHTM active protection circuitry aids in reducing the likelihood of damage
under abusive conditions.
•
Switchable high-pass output on subwoofers maximizes performance when a fullrange system and a subwoofer are powered by a single amplifier channel.
•
Rugged 11-ply cross-laminated Birch enclosures, coated with a two-part catalyzed
polyester paint for durability.
•
Protective steel grilles covered with durable powder-coat finish.
•
Load rated M10 fly points on tops, bottoms and rear of enclosures for safe & easy
rigging (note: M10 fly points are located on the end panels of the subwoofers).
•
Dual NL4-compatible locking connectors, plus dual ¼” jacks allow easy connectivity
with readily available cables.
•
Factory designed rigging hardware available from stock.
UNPACKING AND INSPECTION
S-Series loudspeakers are inherently rugged and are carefully packed in sturdy cartons.
However, it’s wise to thoroughly inspect each unit after it has been removed from the
packaging, as damage could occur during shipping.
Please note that once the shipment has left your dealer or the Community factory, the
responsibility for damage is always borne by the freight company. If damage has occurred
during shipping, you must file a claim directly with the freight company. It’s very important
to contact the freight company as soon as possible after receiving your shipment, as most
freight companies have a short time limit within which they will investigate claims. Make
sure to save the carton and the packing material, as most claims will be denied if these
materials are not retained. Your Community dealer and the factory will try to help in any
way they can, but it is the responsibility of the party receiving the shipment to file the
damage claim.
It’s always a good idea to retain the carton and packing materials indefinitely, if possible, in
the event that the unit may need to be returned to your dealer or distributor for repair in
the future.
Each shipping carton contains the following items:
•
•
•
Loudspeaker System (Qty 1)
Operation Manual (Qty 1)
Warranty Card (Qty 1)
DANGER: S-Series rigging fittings are each rated at a Working Load Limit (WLL) of 100 lbs
(45.4kg) with a 10:1 safety margin. No single rigging fitting should ever be subjected to a
load that is greater than this stated limit. Failure to heed this warning could result in injury
or death!
IMPORTANT: The flat-head Allen-drive rigging screws that come installed in each
enclosure must either be replaced with rigging brackets and threaded fasteners, or they
must be kept in place to seal the enclosure from air leaks. If the rigging fittings do not
remain sealed, air leaks will occur in the enclosure that will compromise the low-frequency
performance with distortion and reduced output.
Community S-Series - Operation and Installation Manual - Page 8
S-Series Specifications
Model
S-1296
S-1596
S-3294
S-3594
S-215S
S-218S
Loudspeaker Type
Two-way, fullrange, vented
bass - switchable
passive or bi-amp
Two-way, fullrange, vented
bass - switchable
passive or bi-amp
Three-way, fullrange, vented
bass - switchable
passive or bi-amp
Three-way, fullrange, vented
bass - switchable
passive or bi-amp
Dual driver
subwoofer, vented
bass - switchable
hi-pass/parallel
output
Dual driver
subwoofer, vented
bass - switchable
hi-pass/parallel
output
Driver Complement
LF: 1 x 12”
LF: 1 x 15”
LF: 1 x 12”
LF: 1 x 15”
LF: 2 x 15”
LF: 2 x 18”
MF: 1 x 6.5”
MF: 1 x 6.5”
HF: 1 x 1”
HF: 1 x 1”
HF: 1 x 1”
HF: 1 x 1”
Nominal Dispersion
(H x V)
90º x 60º
90º x 60º
90º x 40º
90º x 40º
360º x 180º
360º x 180º
Operating Range
60 Hz - 20 kHz
50 Hz - 20 kHz
60 Hz - 20 kHz
55 Hz - 20 kHz
30 Hz - 2 kHz
30 Hz - 1 kHz
Frequency Response
100 Hz - 16 kHz
90 Hz - 16 kHz
90 Hz - 16 kHz
80 Hz - 16 kHz
40 Hz - 200 Hz
40 Hz - 200 Hz
Max Input Ratings
(passive mode)
200W RMS (40V)
200W RMS (40V)
200W RMS (40V)
200WRMS (40V)
400W RMS (40V)
600W RMS (49V)
500W PGM
500W PGM
500W PGM
500W PGM
1000W PGM
1500W PGM
990W PEAK
990W PEAK
990W PEAK
990W PEAK
1980W PEAK
2970W PEAK
Sensitivity 1W/1m
99 dB SPL
102 dB SPL
100 dB SPL
101 dB SPL
97 dB SPL*
100 dB SPL*
Maximum SPL
122 dB cont.
129 dB peak
124 dB cont.
131 dB peak
123 dB cont.
130 dB peak
123 dB cont.
130 dB peak
120 dB cont.
127 dB peak
125 dB cont.
132 dB peak
Nominal Impedance
8 Ohms
8 Ohms
8 Ohms
8 Ohms
4 Ohms
4 Ohms
Input Connection
Dual NL4 with
dual ¼” jacks in
parallel
Dual NL4 with
dual ¼” jacks in
parallel
Dual NL4 with
dual ¼” jacks in
parallel
Dual NL4 with
dual ¼” jacks in
parallel
Dual NL4 with
dual ¼” jacks in
parallel
Dual NL4 with
dual ¼” jacks in
parallel
Rigging Provisions
Eight M10
threaded rigging
fittings - three
each on top and
bottom; two
on rear
Ten M10
threaded rigging
fittings - four
each on top and
bottom; two
on rear
Ten M10
threaded rigging
fittings - four
each on top and
bottom; two
on rear
Ten M10
threaded rigging
fittings - four
each on top and
bottom; two
on rear
Eight M10
threaded rigging
fittings - four on
each end of
enclosure
Four M10
threaded rigging
fittings - two on
each end of
enclosure
Construction
11 ply crosslaminated birch
11 ply crosslaminated birch
11 ply crosslaminated birch
11 ply crosslaminated birch
11 ply crosslaminated birch
11 ply crosslaminated birch
Finish
Black catalyzed
polyester twopart paint
Black catalyzed
polyester twopart paint
Black catalyzed
polyester twopart paint
Black catalyzed
polyester twopart paint
Black catalyzed
Black catalyzed
polyester two-part polyester two-part
paint
paint
H
23.9 in / 607mm
27.2 in / 691mm
29.3 in / 744mm
32.4 in / 823mm
18.4 in / 467mm
21.4 in / 544mm
W
14.9 in / 378mm
18.4 in / 467mm
17.4 in / 442mm
18.4 in / 467mm
37.4in / 950mm
44.4 in / 1128mm
D
13.4 in / 340mm
15.9 in / 404mm
15.4 in / 391mm
15.9 in / 404mm
20.4 in / 518mm
24 in / 610mm
36lbs / 16.3kg
46.5lbs / 21.1kg
53lbs / 24kg
58lbs / 26.3kg
89lbs / 40.4kg
Dimensions
(in / mm)
Weight (lbs / kg)
Due to ongoing development, specifications are subject to change without notice.
Note: *denotes half-space sensitivity.
Community S-Series - Operation and Installation Manual - Page 9
127lbs / 57.6kg
GETTING ACQUAINTED
Figure 1: Physical Features of Typical S-Series Full-Range Models
S-Series Full-Range Input Panel
Community S-Series - Operation and Installation Manual - Page 10
PHYSICAL FEATURES OF S-SERIES FULL-RANGE MODELS
FEATURE
DESCRIPTION
TOP & BOTTOM RIGGING
POINTS
8 total, 4 top and 4 bottom - bottom points not shown1
(note: S-SERIES-1296 has 3 top and 3 bottom).
ERGO-GRIP SIDE LIFTING
HANDLES
2 total.
PROTECTIVE GRILLE
Powder-coated steel grille protects drivers
from foreign objects.
GRILLE RETENTION
SCREWS
Eight (or ten) #6 x 5/8” sheet metal screws,
depending on model.
REAR ERGO-GRIP
LIFTING HANDLE
1 total.
REAR PULL-BACK POINTS
Used for angling enclosure downward; not for primary
rigging.
INPUT PANEL
For amplifier connection to the loudspeaker. Also
contains Bi-amp / Single-amp switch, Presence switch,
and DYNA-TECHTM Protection Indicator.
POLE SUPPORT
RECEPTACLE
Installed on bottom of enclosure. Accepts standard
loudspeaker support pole (1.375” / 35 mm diameter).
FEET
4 synthetic-rubber feet protect surfaces from marring.
PASSIVE / BI-AMP
SWITCH
Used to select loudspeaker’s operating mode. LEFT
position is for PASSIVE mode (single amplifier) and
RIGHT position is for BI-AMPLIFIED mode (separate
LF and HF amplifiers).
NL4-COMPATIBLE
LOCKING CONNECTORS
Two 4-pole NL4MP type loudspeaker connectors wired
in parallel. Accepts NL4FC connectors. Used for both
PASSIVE and BI-AMPLIFIED modes. Use terminals #1
+/– for PASSIVE mode or for BI-AMPLIFIED LF input.
Use terminals #2 +/– for BI-AMPLIFIED HF input (not
used in PASSIVE mode).
¼” JACKS
1
Wired in parallel with Pins #1+ and #1- of both NL4MP
connectors. Note: may only be used in PASSIVE mode.
DYNA-TECHTM
PROTECTION INDICATOR
Red LED indicates that DYNA-TECH active protection
circuits have been engaged, reducing the potential of
driver damage.
PRESENCE SWITCH
Selects between MUSIC (Flat) and VOICE/ SPEECH
(+4dB) operating modes (LEFT position is MUSIC
(Flat), RIGHT is VOICE/SPEECH). Re-voices the
loudspeaker’s tonal balance for increased articulation
in the vocal range.
100 lbs (45.4 kg) Working Load Limit / 10:1 safety factor
Community S-Series - Operation and Installation Manual - Page 11
Figure 2: Physical Features of Typical S-Series Subwoofers
(Note: the S-215S Subwoofer is not equipped with wheels)
S-Series Subwoofer Input Panel
Community S-Series - Operation and Installation Manual - Page 12
PHYSICAL FEATURES OF S-SERIES SUBWOOFERS
FEATURE
DESCRIPTION
LIFTING HANDLES
4 total; 2 on each end panel.
‘HANDTRUCK’ HANDLES
2 total. For tilting the enclosure onto its built-in transport
wheels (model 218S only).
RIGGING POINTS
MODEL S-218S: 4 total; 2 on each end panel2.
MODEL S-215S: 8 total; 4 on each end panel3.
POLE SUPPORT
RECEPTACLE
Installed on top of enclosure. Accepts standard
loudspeaker support pole (1.375” / 35 mm diameter).
Receptacle is sleeved to the bottom of the enclosure for
maximum stability.
PROTECTIVE GRILLE
Powder-coated steel protects drivers from foreign objects.
GRILLE RETENTION
SCREWS
Twenty #6 x 5/8” sheet metal screws.
INTEGRATED TRANSPORT
WHEELS
Dual permanently mounted rigid casters (non-swivel), for
easy transport (model 218S only).
FEET
4 synthetic-rubber feet protect surfaces from marring.
INPUT PANEL
For amplifier connection to the loudspeaker. Also contains
FLAT / HI-PASS Switch and DYNA-TECH protection
indicator.
NL4-COMPATIBLE
LOCKING CONNECTORS
4-pole NL4MP type loudspeaker connectors, wired in
parallel. Accepts NL4FC connectors.
Use terminals #1 +/–.
Terminals #2 +/– are wired in parallel with #1 +/-.
¼" JACKS
2
3
Permanently wired in parallel to Pins #1+ and #1- on the
NL4 closest to the ¼" jack.
HIGH-PASS SWITCH
Selects between HI-PASS OUTPUT and PARALLEL INPUT
MODE on the speaker output connectors (up is HI-PASS,
down is PARALLEL). HI-PASS filter is 125 Hz, 6/dB per
octave with an 8Ω load (note: crossover frequency is load
dependent).
DYNA-TECH PROTECTION
INDICATOR
Red LED indicates that DYNA-TECH active protection
circuits have been engaged, reducing the potential of
driver damage.
100 lbs (45.4 kg) Working Load Limit / 10:1 safety factor
100 lbs (45.4 kg) Working Load Limit / 10:1 safety factor
Community S-Series - Operation and Installation Manual - Page 13
GENERAL DESCRIPTION
S-Series loudspeakers are designed for demanding day-to-day use in a wide range of both
portable applications and fixed installations. Their high quality driver components are
housed in rugged, acoustically inert enclosures fitted with convenient carrying handles,
rigging fittings, and support stand receptacles. S-Series is characterized by a high-power,
low distortion linear response that provides exceptional musicality and speech intelligibility.
The S-Series consists of six models:
•
S-1296 - a 12” / 1” two-way, in a multi-angle enclosure suitable for FOH or
Stage Monitoring.
•
S-3294 - a 12” / 1” three-way which includes the addition of a horn-loaded
6.5” cone driver, in a trapezoidal enclosure.
•
S-1596 - a 15” / 1” two-way, in a trapezoidal enclosure.
•
S-3594 - a 15” / 1” three-way which includes the addition of a horn-loaded
6.5” cone driver, in a trapezoidal enclosure.
•
S-215S - a dual 15” subwoofer, in a rectangular enclosure.
•
S-218S - a dual 18” subwoofer, in a rectangular enclosure with integrated
casters.
Note: All models have integrated support stand fittings.
When used in multiples, S-Series loudspeakers array well. Systems may be designed
around horizontal splayed arrays, vertical splayed arrays, as well as exploded clusters and
distributed configurations. Rigging kits are available from the factory as standard items
(see the section on Rigging Hardware on page 46).
The specifications table on page 9 depicts dimensions, weights and general specifications of
the various S-Series models.
DYNA-TECH DRIVER PROTECTION SYSTEM
All S-Series loudspeakers employ Community’s advanced technology DYNA-TECH driver
protection system. Functioning as a multi-stage limiter, DYNA-TECH circuitry provides
precise and repeatable protection by reducing excessive power to the drivers under abusive
conditions.
The first stage of limiting is designed to protect against short-term excess power applied to
the high-frequency driver(s) in the system. This circuit utilizes an HPCCR (High Positive
Current Coefficient Resistor) in series with the driver(s). The HPCCR increases resistance
as the current flowing through it increases. As its resistance rises above nominal, the
heating of the element provides RMS conversion. The result is an RMS limiter with a ratio
that varies according to the demands of the program material.
The second stage of limiting protects against excessive power levels to all drivers in the
system. This stage is based on a relay driven through a voltage sensing circuit. The relay
engages at a pre-determined voltage, corresponding to a power level that would otherwise
cause driver damage. When engaged, the relay introduces a bank of high-wattage resistors
in series with the drivers. These resistors cause a voltage drop to the drivers, thereby
reducing the power applied to them. A red LED on the rear panel indicates that this
protection circuit has been engaged.
When the relay protection circuit is activated, there will be a noticeable drop in the system’s
level (approximately 3 to 4 dB). The red LED, as well as the drop in level, serves as a
warning to the operator that the loudspeaker is being overdriven. When this stage of
protection is engaged, the level of console and/or amplifier output to the system
should be reduced.
Community S-Series - Operation and Installation Manual - Page 14
IMPORTANT: If the operator continues to run the system at excessive levels, or worse, if
the operator raises the drive level to compensate for the drop in output caused by the
protection circuitry, eventually an additional stage of protection will engage that shuts down
the system entirely (note that this additional stage of protection will never engage until
after the second stage has been triggered). If the system shuts down entirely, the operator
can immediately restore sound by merely reducing the drive level to the system.
Advantages of Community’s DYNA-TECH Circuitry
There are numerous advantages to this type of multi-stage protection circuitry. The trip
point is pre-set to engage at exactly the same time on all speakers that are powered from
the same amplifier. The initial stages of DYNA-TECH protection circuitry do not rely on, and
are not affected by heat build-up. Some manufacturers use circuit breakers that require
heat build-up before they trip; this limits their ability to protect a cold speaker. The trip
points of such breakers are also affected by ambient temperature, their own internal
heating curves, and small variations in speaker impedance or crossover component
tolerances, all of which can cause unpredictable behavior.
Because the first and second stages of Community’s DYNA-TECH circuits are not thermally
sensitive, they react nearly instantaneously to protect against excessive increases in level.
Moreover, the protection disengages almost immediately when the level is reduced; it is not
necessary to wait for a circuit breaker to cool down. This means that your loudspeaker can
operate at its full dynamic range and still react quickly to excessive musical peaks, without
fear of damaging the system. It also means that your loudspeaker is protected from the
moment the power amplifier is plugged in and turned on, regardless of the ambient
temperature.
As mentioned above, the protection circuitry provides an additional level of protection for
the entire loudspeaker to guard it from severe misuse. If the system is operated in the
second-stage protection mode for a long period of time, or if the input level is increased by
someone trying to overcome the volume drop from the second-stage protection circuit, a
solid-state circuit breaker will trip and remove all signal from the loudspeaker until the
input level is reduced. Because this circuit breaker is heat sensitive, it provides a final level
of protection that takes heat into account as well as power. However, unlike most
implementations of circuit breakers that take time to cool down before resetting, DYNATECH circuits respond instantly to a reduction in level, restoring the system to its full
dynamic range without needing to wait for the circuit breaker to reset itself.
HIGH-FREQUENCY PRESENCE SWITCH
Each S-Series full-range loudspeaker is equipped with a Presence Switch on its rear input
panel. This switch selects between two different high-frequency contours to adjust the
voicing of the loudspeaker. Using the Presence Switch allows you to optimize the audio
quality for different performers, for varying types of program material, and for differing
acoustical environments.
One position of the Presence Switch is labeled MUSIC (FLAT) while the other position is
labeled VOICE-SPEECH (+4dB). In the MUSIC (Flat) position, the response of the
system is essentially flat; in other words it will exhibit no significant variation in amplitude
throughout its operating range. In the VOICE-SPEECH (+4dB) position, the mid band
between approximately 2 – 4.5 kHz is accentuated by approximately +4dB for increased
articulation in the vocal range, with less accentuation extending from approximately 1 kHz
to 8 kHz.
Community S-Series - Operation and Installation Manual - Page 15
Figure 3: Graph Depicting Frequency Response of MUSIC / VOICE
Presence Switch (Note: the Voice/Speech position is represented by the dotted line)
Resolution <500 Hz = 10 Hz, >500 Hz = 40 Hz, 1/2 octave smoothing
110
100
90
dB
80
SPL
70
10
100
1,000
10,000
100,000
Frequency in Hertz
C-TIP: The VOICE-SPEECH (+4dB) position may be useful when trying to compensate for
absorption loss over very long distances, or just when some additional presence is needed
to achieve the tonal quality you’re seeking. Note: This switch is active in both the PASSIVE
and BI-AMP modes.
SELECTABLE HIGH-PASS OUTPUT ON SUBWOOFERS
S-Series subwoofers are equipped with an industry-standard NL4-compatible locking
connector wired in parallel with a ¼” jack. A second NL4-compatible locking connector is
provided, also wired in parallel to a ¼” jack. This second set of connectors is intended as
OUTPUTS and are associated with the subwoofer’s SWITCHABLE HIGH-PASS OUTPUT.
When the selector switch is set to the PARALLEL INPUT MODE (the down position), both
the NL4-compatible locking connector and the 1/4” jack function exactly as loop-thru
connectors; in other words they are simply wired in parallel with the INPUT
CONNECTORS.
Conversely, when the selector switch is set to HIGH-PASS OUTPUT (the up position), a 1st
order high-pass filter (6 dB per octave) is inserted into the circuit. The filter has a corner
frequency of 125 Hz with an 8 ohm load.
Using the HIGH-PASS OUTPUT MODE inserts the HIGH-PASS FILTER as mentioned above,
but it also presents a higher impedance load to the amplifier. This can become quite
important, particularly if a pair of full-range loudspeakers and a subwoofer are being
powered from a single amplifier channel. In the PARALLEL INPUT MODE, the impedance of
the combined load could become dangerously low for some amplifiers, potentially causing
the amplifier to shutdown or fail.
The following graph shows the difference in the total load impedance with the high-pass
switch in the HIGH-PASS and PARALLEL INPUT MODE positions. The lower line depicts the
response with the switch in the FLAT position where the load drops below 2 ohms between
30 – 50 Hz and again between 100 – 200 Hz, potentially causing early clipping, amplifier
shutdown, or even amplifier failure. The upper line depicts the response with the switch in
the HIGH-PASS position, where the load impedance has been increased by about 50% by
the subwoofer’s internal crossover circuit, thereby protecting the amplifier from premature
clipping and potential failure.
Community S-Series - Operation and Installation Manual - Page 16
Figure 4: Graph Depicting Response of HIGH-PASS / FLAT Switch
(Note: upper line depicts HIGH-PASS; lower line depicts FLAT)
HIGH-PASS position
FLAT position
In addition to presenting a more amplifier-friendly load, the HIGH-PASS OUTPUT also
attenuates the low-frequency energy that’s fed to the full-range loudspeaker. This reduces
the demand on the full-range loudspeaker’s woofer, thereby freeing up some additional
power and headroom in the upper part of the bass spectrum. Use of the HIGH-PASS
OUTPUT will typically result in an overall flatter response, but with slightly less total power
available in the mid-bass portion of the audio spectrum.
The results you achieve will be strongly influenced by the relative locations of the full-range
loudspeaker(s) and the subwoofer(s), their position in relation to the walls, floor or ceiling,
as well as the overall room acoustics. For example, if a full-range model is stacked on a
subwoofer, the combined response will be different than if it is flown 15 or 20 feet over the
subwoofer. We encourage you to experiment to obtain the quality of sound that is to your
liking.
IMPORTANT: The corner frequency of the HIGH-PASS FILTER is load dependent (this is
the case with all passive filters). This means that the frequency will alter if the impedance
of the load changes. For example, if two 8 ohm full-range enclosures are connected to the
high-pass output in parallel, the resultant 4 ohm load will change the high-pass corner
frequency to 250 Hz.
C-TIP: For exact control in balancing the relative levels of the subwoofer(s) and the fullrange loudspeaker(s), we recommend that separate amplifier channels be employed to
power each unit individually. Moreover, if an electronic active crossover is used to divide
the signal to the subwoofer(s) and the full-range loudspeaker(s), this will result in biamping the two systems. Bi-amping provides the benefit of reducing the overall power
demand on each amplifier channel while reducing intermodulation distortion.
Community S-Series - Operation and Installation Manual - Page 17
COOL-COIL™ TECHNOLOGY
The cone drivers used in the S-Series subwoofers utilize Community’s patented Cool-Coil™
heat evacuation technology. A proprietary process, Cool-Coil employs an airflow director to
remove heat from the voice coil, thereby increasing both the performance and reliability of
the cone drivers. In particular, the effect of Power Compression is significantly improved by
Cool-Coil technology. Power Compression occurs when drivers respond non-linearly to
applied power, producing less and less output as their voice coils heat up and their
impedance rises.
High voice coil temperatures have other undesirable effects on performance. Most materials
used in drivers, particularly adhesives and insulation, suffer some diminished properties
under extremes of heat. Thermal expansion can result in warpage and misalignment of
components. A voice coil in which the diameter has increased due to thermal expansion
will often no longer be round, and certainly has a greater possibility of rubbing against the
magnetic structure.
Any amount of cooling that can be applied to a woofer will be beneficial. One very
commonly used cooling method is venting of the pole piece of the magnet structure. The
motion of the cone assembly will pump air in and out of the cavity under the dust cap. This
air passing through the pole vent helps to cool the magnet structure. Community has
improved on this common cooling method by introducing an airflow director (US patent
6,390,231) into the air path. Figure 5 shows a conventional woofer motor with a vented
pole piece, and also a similar motor with the addition of an airflow director. The voice coil
former in the airflow motor is aluminum, and is taller than normal. This extended
aluminum former becomes a cooling fin for the voice coil, and the airflow director causes
the air to pass in close proximity to the former. By directing the air to flow over the hot
aluminum former, more heat is removed from the voice coil than simply allowing the
pumped air to take its natural path in and out of the cavity. This results in woofers that can
handle higher power with greater reliability than those of conventional design.
Figure 5: Community’s Cool-Coil™ Heat Evacuation System
OPERATING IN PASSIVE OR BI-AMPED MODE
All S-Series full-range loudspeaker models may be operated in either the passive mode or
the bi-amped mode.
A switch on the full-range loudspeaker input panel selects between the two operating
modes: PASSIVE mode (single amplifier) or BI-AMP mode (separate low and high frequency
amplifiers). In both PASSIVE and BIAMP mode, the internal crossover divides the audio
signal into the separate frequency ranges for each of the drivers.
Community S-Series - Operation and Installation Manual - Page 18
In PASSIVE mode one amplifier is used to power the entire loudspeaker. In BI-AMP mode
one amplifier is used to power the low frequency section and another is used to power the
high frequency section. The separation of high and low frequencies is done internally in the
loudspeaker, so no electronic crossover is required. Simply run full-range signals into the
amplifiers and connect the outputs to the appropriate HF and LF terminals on one of the
Neutrik input jacks. Use the amplifier input level controls to balance the HF to LF acoustic
outputs.
Alternatively, an electronic crossover can be used before the amplifiers in the signal chain
to optimize the bandwidth of audio supplied to the amplifiers. This would prevent, for
example, the high-frequency amplifier from being burdened with full-range (including low
frequency) content. Use of an electronic crossover can be helpful but is not necessary.
CAUTION: A system set up for either the passive or bi-amp mode of operation should
never be switched to the opposite mode without first appropriately re-wiring the system!
Damage to the high-frequency driver could readily occur. At best, the system will not
sound or perform properly. Make sure to always disconnect the amplifier and reconfigure the wiring before changing from one mode of operation to the other.
C-TIP: Bi-amping will almost always result in cleaner, more faithful reproduction of the
program content, particularly noticeable at high levels or when reproducing complex, fullrange material. If the budget permits, we recommend bi-amping as the best solution.
HIGH-PASS FILTERS
When operating in either the passive or the bi-amplified mode, we strongly recommend the
use of an external, active high-pass filter to protect the cone drivers from excessive lowfrequency excursion. High-pass filters will eliminate the potential of low-frequency
modulation from wind noise, turntable rumble, stage vibration, and other causes that result
in a poorly defined and ‘muddy’ bass response. Additionally, a high-pass filter will avoid
wasting amplifier power by stopping the amplifier from attempting to reproduce frequencies
below the loudspeaker’s intended operating range.
The table below shows the recommended filter settings:
Model
High-Pass Filter
S-1296 Full-Range:
60 Hz, 24db/octave
S-1596 Full-Range:
50 Hz, 24db/octave
S-3294 Full-Range:
60 Hz, 24db/octave
S-3594 Full-Range:
55 Hz, 24dB/octave
S-215S Subwoofer:
30 Hz, 24db/octave
S-218S Subwoofer:
30 Hz, 24db/octave
CHOOSING ACTIVE CROSSOVERS
A wide variety of active crossovers and loudspeaker control systems are available from
numerous manufacturers. Most of today’s products use DSP (Digital Signal Processing) to
divide the frequency bands and provide equalization, protective limiting, and signal delay.
The use of a good quality DSP processor or ‘loudspeaker management tool’ as many such
devices are often referred to, is strongly encouraged. When properly utilized, a DSP
processor provides numerous benefits that contribute to better quality sound and longer
system life. Please contact Community or your Community dealer for up-to-date
recommendations regarding specific types and models of available DSP products.
Community S-Series - Operation and Installation Manual - Page 19
USING PROTECTIVE LIMITERS
Although S-Series loudspeaker systems are well protected against potentially abusive
operating conditions by their internal DYNA-TECH protection circuits, the use of an active,
outboard limiter can add an extra measure of insurance for long-term reliability.
Additionally, an active outboard limiter can be adjusted to provide a subtler degree of driver
protection, precisely tailored to each user’s specific needs in terms of musical styles and
operating conditions.
A limiter is a device that detects the level of the signal that it’s receiving over a given
interval or “time constant.” When the input level crosses a certain threshold, for longer
than a certain time period, the limiter introduces some degree of gain reduction. In turn,
the gain reduction reduces the dynamic range of the program material that reaches the
amplifier.
Limiters, and their close cousin Compressors, are used in music recording and sound
reinforcement to create certain effects such as perpetual sustain of guitar and bass notes.
They’re also widely used to reduce or eliminate peak levels from vocalists, percussionists,
and other dynamic sources, as well as often being employed to avoid overdriving amplifiers
and speakers.
Limiters that are suitable for protecting loudspeaker systems are available as stand-alone
products, as well as often being included as a function of many DSP based loudspeaker
controllers or ‘loudspeaker management systems.’
Limiters typically allow adjustment of some or all of the following parameters:
•
•
•
•
•
•
Threshold
Input Level
Output Level (frequently called ‘makeup gain’)
Attack Time
Release Time
Compression Ratio
Virtually all limiters allow the user to set the threshold, or level, at which point gain
reduction will occur. Most models also permit the user to adjust the limit ‘ratio.’ Ratio
refers to the magnitude of gain reduction. At a 2:1 ratio, every 2 dB increase in input level
above the threshold will result in a 1 dB increase in output. At a 10:1 ratio, every 10 dB
increase in level above the threshold will also result in a 1 dB increase in output. From
these two examples, you can readily see how the Ratio control settings will affect the
dynamic range.
Incidentally, the term ‘limiting’ generally refers to ratios of 10:1 or higher (some say 20:1),
whereas ‘compression’ is the term used for lower ratios, such as 2:1 or 4:1. In fact, the
only distinction between ‘compression’ and ‘limiting’ is the ratio of gain reduction.
Many limiters will allow the user to set the time constant that determine the length of the
transients that are permitted to pass before the limiting function engages (this is called
Attack), as well as the time span in which the limiter will ‘recover,’ or return to a state of
non-limiting (called Release).
When used to protect a loudspeaker system, the limiter should be set so that gain reduction
engages at some point before damage occurs to the drivers. If the threshold is set too low,
the resultant sound quality will be ‘squashed.’ In other words, the dynamic range of the
program material will be reduced to a degree that is audibly unpleasant. Conversely, if the
threshold is set too high, the limiter will not engage early enough to protect the
loudspeaker system from damage.
It is very difficult to suggest exact limiter settings, because the ideal setting for one system
and one style of music may be undesirable for another system or another style of music.
Coupled with this, the dynamic response characteristics of the amplifier(s) used in the
system also play a large role in determining proper limiter adjustments. Amplifiers differ
from one make and model to another in their dynamic headroom capability, sometimes
greatly, and also in how they behave when they clip (see section on Amplifier Clipping on
page 30 for more information on driver damage caused by clipping.) Because of this, we
can offer only general guidelines on how to set up your system.
Community S-Series - Operation and Installation Manual - Page 20
Following is a brief discussion on using limiters to protect loudspeaker systems:
•
The limiter should be set so that it provides some measure of gain reduction before
the amplifier(s) begin to clip. If the limiter is set so that it allows the amplifier(s)
to go into hard clipping, it will do little to protect the drivers, except perhaps in the
event of extended microphone feedback.
•
If the system is large enough to handle the intended musical style in the size of
room that it’s designed to cover, i.e. if there are enough amplifiers and
loudspeakers to provide the desired SPL (Sound Pressure Level) before the
amplifiers reach clipping, then it will be possible to adjust the protective limiter so
that the amplifiers never can go into clipping, even under abusive conditions. This
will provide an excellent level of protection, without sacrificing headroom and
sound quality.
Conversely, if the system is inadequately sized for the room, or just barely
powerful enough, setting the limiter so that the amplifier(s) never goes into
clipping is probably unrealistic. Such a setting will most likely result in less sound
pressure level than desired, as well as a highly compressed sonic quality. In such
case, you can either upgrade the sound system by adding loudspeakers and
amplifiers, or you can make some intelligent compromises. By carefully adjusting
the attack time, release time and threshold level, you can allow some of the peaks
to get through to the amplifiers while still reducing the potential for damage from
long-term abuse.
•
A fast attack time (under 10 ms) will limit most of the peaks in normal program
material. By lengthening the attack time, you can allow short transients to pass
through (like a snare drum), while still reducing longer peaks like vocal and
instrumental crescendos. This will improve the dynamic range, while still providing
a measure of protection.
•
Similarly, a long release time will tend to squash the program material, as well as
introduce an audible ramp-up in level as the limiter slowly recovers. By shortening
the release time, you can increase the short-term dynamic range. As long as the
threshold is not set too high, the limiter can still aid in protecting the drivers from
long-term overdrive, but not as thoroughly as it would in an adequately sized
system.
Be cautious of very short attack and release times, as the detector circuits may
start to track the individual cycles of a sustained low-frequency tone, creating a
‘pumping’ effect, almost like that of a tremolo circuit on a guitar amplifier.
It will take some experimentation to derive the best settings for each situation. Maximum
power and voltage ratings are stated on the S-Series Specification Table on Page 9 in this
manual; these may be used as an aid in calibrating limiter settings. Using a true RMS
voltmeter, you can measure the output of your amplifier when driven by a sine wave
generator, and adjust the limiter to prevent the amplifier’s output voltage from exceeding
the stated maximum. Make sure to do this with the loudspeaker disconnected!
Be aware, however, that static voltage settings made by taking measurements derived from
exciting the system with a sine wave generator, or other constant voltage source, will
represent only a part of the picture. The other part is the time constant. If the attack and
decay times are too long, the limiter will not protect against short-term transients; in fact,
it may never engage at all.
In summary, a protective limiter can go a long way towards preserving the lifespan of a
loudspeaker system, but only if the system is sized properly to begin with and the limiter is
carefully adjusted to properly complement the system. Obviously, it’s safer to err on the
conservative side, as the opposite approach may result in driver damage or complete
system failure.
Community S-Series - Operation and Installation Manual - Page 21
CONNECTING THE AMPLIFIER TO THE LOUDSPEAKER
All S Series loudspeakers come with two methods of connecting the amplifier to the
loudspeaker. One is a pair of industry standard NL4 type locking connectors, and the other
is a pair of ¼” jacks. With the exception of the S-Series subwoofers, which feature a
switchable High-Pass output, the four connectors are wired in parallel with each other on all
full-range models.
When there’s a choice, we recommend using the NL4 type connectors whenever possible.
NL4 connectors have higher current handling capability than ¼” connectors. They’re much
easier to wire and far less prone to corrosion or mechanical degradation, which can result in
an intermittent connection. Finally, they feature a positive locking mechanism when mated.
If you’ve ever had a loudspeaker quit during a gig because someone tripped over the
speaker cable, you’ll appreciate the extra security of a locking speaker cable connector.
IMPORTANT: If you do elect to use ¼” loudspeaker cables, make sure to obtain high
quality cables designed and built for loudspeakers. Never use signal cables made for guitars
and keyboards, as they are not capable of handling the power. As such, they will degrade
the sound quality and may even short out, or literally burn up under sustained usage.
Community S-Series - Operation and Installation Manual - Page 22
Figure 6: S-Series Full-Range Input Panel
The following figure is an example of the input panel used on full-range S-Series
loudspeakers.
Full-Range Input Panel (Typical)
Community S-Series - Operation and Installation Manual - Page 23
PIN DESIGNATIONS
In Passive Mode the pin designation is as follows:
•
•
NL4 Pin 1+ and the tip of the ¼” jack connect to the positive (red) output of
the amplifier.
NL4 Pin 1- and the sleeve of the ¼” jack connect to the negative (black)
output of the amplifier.
Internally, these pins are connected to the passive crossover in the loudspeaker.
Note: Pin 1+ and 1- and Pin 2+ and 2- are always connected in parallel to the second
NL4 connector. However, only Pin 1+ and 1- are connected to the ¼” jacks, as they are
two pole wiring devices. In the Passive Mode, Pin 2+ and Pin 2- are not connected
internally to any loudspeaker components.
In Bi-amp Mode the pin designation is as follows:
•
•
•
•
NL4 Pin 1+ connect to the positive (red) output of the amplifier powering the
low-frequency driver.
NL4 Pin 1- connect to the negative (black) output of the amplifier powering
the low-frequency driver.
NL4 Pin 2+ connect to the positive (red) output of the amplifier powering the
high-frequency driver.
NL4 Pin 2- connect to the negative (black) output of the amplifier powering
the high-frequency driver.
Internally these pins connect to their respective low-frequency and high-frequency drivers
through the internal passive crossover circuits, thereby deriving an added degree of driver
protection.
IMPORTANT: The ¼” jack is a two-pole wiring device and therefore cannot be used in the
Bi-amp Mode. Bi-amping, by its nature, requires a four-pole connector.
CAUTION: Be sure to carefully observe polarity when wiring your loudspeaker(s). If one
loudspeaker is wired with the opposite polarity from another loudspeaker, acoustic
cancellation will occur. The result will be less total acoustic power output than if only one
loudspeaker were used by itself.
Community S-Series - Operation and Installation Manual - Page 24
Figure 7: S-Series Subwoofer Input Panel
The following figure is an example of the input panel used on S-Series subwoofers.
Subwoofer Input Panel (Typical)
PIN DESIGNATIONS
In the Parallel Output Mode the pin designation is as follows:
•
•
NL4 Pin 1+ and the tip of the ¼” jack connect to the positive (red) output of
the amplifier.
NL4 Pin 1- and the sleeve of the ¼” jack connect to the negative (black)
output of the amplifier.
Internally, each of these pins are connected to the NL4 output connector, to the ¼” output
jack, and to the drivers in the subwoofer.
In the Hi-Pass Mode the pin designation is as follows:
•
•
•
NL4 Pin 1+ and the tip of the ¼” jack connect to the positive (red) output of
the amplifier.
NL4 Pin 1- and the sleeve of the ¼” jack connect to the negative (black)
output of the amplifier.
Either the NL4 or the ¼" jack on the right side of the input panel may be used
as hi-pass outputs to drive one or more full-range loudspeakers. These hi-pass
outputs exhibit the response that is discussed in the section of this manual
entitled “SELECTABLE HIGH-PASS OUTPUTS ON SUBWOOFERS.” This
Section can be found on Page 16.
Community S-Series - Operation and Installation Manual - Page 25
WIRING NEUTRIK TYPE CONNECTORS
The diagrams below show how connections are made to a Neutrik SpeakonTM style
loudspeaker connector. Terminations may be soldered, or made by means of their built-in
screw and pressure clamp. If using the pressure clamp, it’s important to tighten it fully,
then to wait about ten minutes (longer is better), then to tighten it again. This is because
copper wire flows under pressure. After initially tightening the screw clamp, some minutes
later the screw will no longer be as tight due to the effect of the compression on the
copper. Typically, only one cycle of “tighten – wait – re-tighten” is required for a secure
connection.
Figure 8: Single Amp Connections
Figure 9: Bi-amp Connections
DANGER: When wiring the amplifier(s) to the loudspeaker(s), always power-down the
amplifier(s) and disconnect their AC Mains plug(s). Many modern, high power amplifiers
can deliver enough voltage and current to cause a harmful or lethal electric shock. Shocks
from very low frequencies, such as kick drums, can cause the human heart to stop beating
at relatively low power levels.
WARNING: After wiring the amplifier(s) to the loudspeaker(s), first power up all devices
that are upstream of the amplifier, such as mixers, equalizers, compressor/limiters, etc.,
before powering-up the amplifier. This is to avoid passing any clicks or pops that may
originate in the upstream devices to the loudspeakers. The amplifier should initially be
powered-up with its gain controls turned all the way down. After making sure that a
continuous signal is present, such as a CD playing, slowly raise the level of the gain
controls to establish that the wiring has been installed correctly. Only then should the
loudspeaker be operated at normal output levels.
CAUTION WHEN BI-AMPING: In the bi-amp mode, be particularly careful to insure that
the connections to the low-frequency and high-frequency drivers have been wired correctly.
If the amplifier channels are inadvertently swapped, the low-frequency content could cause
damage to the high-frequency driver or your amplifier. At best, it will simply sound very
bad.
Community S-Series - Operation and Installation Manual - Page 26
Impedance and Paralleling Loudspeakers
Loudspeakers of identical type may be connected together on the same amplifier. This
forms a parallel circuit. When two loudspeakers are connected in parallel, the nominal
impedance of the circuit will divide in half. For example, if two 8 ohm loudspeakers are
wired in parallel, the result will be a 4 ohm load and the power from the amplifier (voltage x
current) will be divided equally between both. If four 8 ohm (or two 4 ohm) loudspeakers
are wired in parallel, the result will be a 2 ohm load. Again, the power will be divided
equally among the loudspeakers.
If an uneven number of loudspeakers are to be connected in parallel, you can use the
following formula to calculate the resultant impedance, where Z is the impedance in ohms:
(1/Z1) + (1/Z2) + (1/Z3) +… = (1/Zt) = Z.
In the above formula Z1 is the impedance of the first loudspeaker, Z2 is the impedance of
the second loudspeaker, Z3 is the impedance of the third loudspeaker, etc., and Zt is the
sum total of the loudspeaker impedances.
Here is an example using 3 loudspeakers, each with an 8 ohm impedance:
(1/8) + (1/8) + (1/8) = (1/0.375) = 2.6666 ohms.
Unequal Impedances
It’s important to note that when wiring loudspeakers of unequal impedances in a parallel
circuit, the power will not be divided equally among each loudspeaker. For example, if an
8 ohm and a 4 ohm loudspeaker are wired together in parallel, the resultant load will be 2.6
ohms. The 4 ohm loudspeaker will draw twice as much current from the amplifier as the 8
ohm loudspeaker. In this example, if the amplifier is capable of producing 1800 watts into
the 2.6 ohm load of the combined loudspeakers, the 4 ohm loudspeaker will receive 1183
watts while the 8 ohm loudspeaker receives only 591 watts.
Know Your Amplifier
Not all amplifiers can safely drive low-impedance loads, though usually 4 ohms and higher
is not a problem. Very low impedance loads may cause the amplifier to clip prematurely,
overheat, shutdown, or fail altogether due to internal device damage.
Even when an amplifier is quite stable driving a low impedance load, cable loss will be
greater than with moderate impedance loads, damping factor will be reduced, and if the
amplifier were to fail, a larger portion of the sound system is likely to be taken off-line due
to the fact that a low impedance load implies a larger number of loudspeakers being
powered from a common amplifier.
C-TIP: Keeping the loads at 4 ohms or higher will lengthen the life of your amplifier(s) and
improve the reliability and overall sound quality of the system.
Choosing Loudspeaker Wire
Wire and cable is used to transfer power between the amplifier and the loudspeaker. Wire
and cable can be purchased with copper and aluminum conductors; for loudspeakers only
copper conductors should be utilized.
The construction, conductor type, and insulation material of wire and cable vary widely.
Wire can be purchased with solid core construction, stranded core construction, and densely
stranded construction. Cables are typically available only as stranded or densely stranded.
Speakers may be driven through individual conductors bundled together and pulled through
conduit, or through a cable made up of a number of conductors covered with an overall
jacket, which then may or may not necessarily be installed in a conduit. Wire and cable
manufacturers offer multi-conductor cables with 30 or more high current conductors
Community S-Series - Operation and Installation Manual - Page 27
covered with a variety of jacket types. Jackets may be made of PVC, rubber, neoprene,
and other materials, depending on the intended conditions of use.
Generally speaking, the wires and cables that power loudspeakers do not need to be
twisted into pairs, though there is some benefit to doing so. A twisted pair of conductors
has the effect of cancelling electro-magnetic radiation, thereby reducing mutual induction
among circuits that share the same physical space (such as a cable tray or conduit), along
with the crosstalk that might otherwise result.
Twisted pairs are commonly used for balanced line signal and microphone cables, in which
the nominal voltages are very low and the input impedance of the load is typically quite
high (>10K ohms). Under such conditions, the use of a twisted pair is essential to reduce
crosstalk among adjacent cables. The twisting insures that the differential amplifier in a
balanced line receiver will see identical phase and amplitude of any extraneous Electro
Magnetic Interference (EMI) induced in the cable on both polarities, thereby allowing the
EMI to be differentially cancelled.
In contrast, however, loudspeakers have input impedances that are quite low and operate
on much higher voltages. The potential of inducing an audible signal from adjacent wiring
is close to zero. The installer may, however, choose to use twisted pair loudspeaker cable
for other reasons. Certain amplifiers may exhibit instability when driving long lengths of
wire installed in conduit. A twisted pair will insure that the reactance of the loudspeaker
cable is identical on both the plus and minus wires, thereby presenting a more stable load
to the amplifier.
Note that when specifying multiple twisted pairs of speaker cables intended to share the
same conduit, the conduit will need to be sized much larger than with loose or bundled
conductors.
Conductors and Insulation
Solid conductor wire is slightly less expensive than stranded wire, but much more difficult
to pull through conduit. Also, it does not terminate to most speaker connectors as easily as
stranded wire. Therefore, we recommend using stranded THHN type wire for installations
that involve conduit.
Densely stranded cables, typically used for portable cordage, will coil up easily and lay flat
on the stage, making them a good choice for applications requiring portability such as floor
monitors. Typical examples are 14/2 and 14/4 SJO. Such cable is normally stocked in
many hardware stores.
Wire and cable insulation is always rated for a working voltage and a maximum
temperature. In power distribution systems, wire and cables can get very hot, making the
temperature rating extremely important. When used with loudspeakers, the temperature of
the wire or cable will hardly ever rise more than 10º C above ambient, and voltages will
never exceed 300V (which is the minimum rating of most industrial wire and cable).
Special cables are manufactured for installation in air plenums, while others are made for
direct burial. Use of such products can save a lot of time and expense compared to
installing conduit. However, local, state, or federal building codes may require that
loudspeaker cables be installed in conduit or in cable trays. It’s a good idea to check
applicable regulations carefully, before beginning the installation.
Conductors are sized according to a numbering system know as the American Wire Gauge,
or AWG. Larger numbers, such as #22 or #24 indicate smaller diameter wire, while smaller
numbers such as #10 and #12 indicate larger diameter wire.
The larger the diameter, the lower the resistance will be for a given conductor length.
Resistance is normally stated per foot, or per hundred feet of wire. For example, #10
stranded copper THHN has a resistance of .204 ohms per hundred feet, though this can
vary slightly among manufacturers.
The resistance of the wire, the impedance of the load, and the output voltage of the
amplifier will determine how much loss occurs in the wire. These parameters also govern
the damping factor of the amplifier/speaker combination (more on this later).
Community S-Series - Operation and Installation Manual - Page 28
Below is a table that gives a quick look at the effect of wire size on line loss. These
numbers assume that the amplifier is producing a constant 48 Volts at its output terminals,
which is equivalent to 288 watts into 8Ω or 576 watts into 4Ω:
Size
Length
Load Z
Loss in dB
#10 AWG
100’
8Ω
-0.42 dB
#10 AWG
200’
8Ω
-0.83 dB
#10 AWG
100’
4Ω
-0.83 dB
#10 AWG
200’
4Ω
-1.58 dB
#12 AWG
100’
8Ω
-0.66 dB
#12 AWG
200’
8Ω
-1.28 dB
#12 AWG
100’
4Ω
-1.28 dB
#12 AWG
200’
4Ω
-2.39 dB
#14 AWG
100’
8Ω
-1.03 dB
#14 AWG
200’
8Ω
-1.95 dB
#14 AWG
100’
4Ω
-1.95 dB
#14 AWG
200’
4Ω
-3.55 dB
The worst-case scenario shown above is the 200’ run of #14 AWG into a 4 ohm load. This
will result in a staggering loss of -3.55 dB, or more than half of the amplifier’s total power
output. Use of wire that’s one size smaller, #16 AWG, would cause a power loss of -5.11
dB. As you can readily see, it’s very important to use the largest gauge wire that you
possibly can, particularly when long lines are unavoidable. NL4-compatible connectors can
easily accept #12 AWG.
C-TIP: When choosing cable for a situation that requires only two conductors, consider
using 14/4 (that is, #14 AWG with 4 conductors) and wiring each pair of conductors in
parallel, at both ends of the cable. This will provide the equivalent conductance of #11
AWG, but in a cable that’s more easily obtainable and smaller in diameter.
The Effect of Wire Gauge on Damping Factor
As significant as power loss can be, the effect of wire resistance on the damping factor of
the loudspeaker/amplifier network is even greater for a given resistance value. (For a
description of Damping Factor, see page 32)
Amplifier designers intend for the output impedance of their amplifiers to be as low as
possible, in order to achieve a high damping factor. However, the laws of physics dictate
that a very low output impedance will cause the resistance of the speaker cable to have a
significant effect on the amplifier/speaker network. Unfortunately there’s no way to get
around it.
Example: With five feet of #10 AWG feeding a 4 ohm load, a given amplifier exhibits a
respectable 100:1 damping factor. With fifty feet of #10 AWG feeding the same 4 ohm
load, the damping factor decreases to 10:1, which is likely to be audible as a loss of ‘punch’
and tightness in the low frequencies.
Unless the power amplifiers are located directly alongside the loudspeakers (a good design
technique to consider when possible), it will be difficult to maintain a high damping factor
without using impractically large conductors. Therefore, keeping cable lengths as short as
possible, is the most practical and cost-effective way to maintain a respectable damping
factor without incurring undue difficulties.
Community S-Series - Operation and Installation Manual - Page 29
C-TIP: Although it’s beyond the scope of this manual to test and rate the many specialty
loudspeaker cables sold in audio shops, studies conducted by skilled engineers have
conclusively shown that the majority of such cables offer no real performance advantages
(and in some cases, notable disadvantages) over that of good quality industrial grade wire.
SELECTING AMPLIFIERS
Amplifiers are a vital part of any sound system’s performance capability. As such, they
should be carefully selected for appropriate power output, as well as for other attributes
(more on this later). A table is provided below to help you size your amplifiers’ power
output capability to the various models in the S-Series.
Model
Recommended Power
S-1296
S-1596
S-3294
S-3594
Full-range (Passive Mode): 400 to 625 WRMS at 8Ω
S-1296
S-1596
S-3294
S-3594
Bi-amp Low-frequency: 400 to 625 WRMS at 8Ω
Bi-amp High-frequency: 100 to 150 WRMS at 4Ω
S-215S Subwoofer
800 to 1250 WRMS at 4Ω
S-218S Subwoofer
1200 to 1875 WRMS at 4Ω
Note: “WRMS” = “Watts RMS” = “Watts Root Mean Squared”
A WORD ABOUT CLIPPING
Clipping occurs when an amplifier is driven to the point where its output can no longer
accurately reproduce the waveform presented at its input. When driven hard enough its
output voltage can’t swing any higher, so the resultant waveform is said to be clipped (see
Figure 10 below).
Figure 10: Effect of Clipping on a Sinewave
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Most waveforms that occur in music and speech are the complex conjugate of sine and
triangle waves. Such waveforms have a relative short duty cycle, cresting to maximum
voltage for only a small part of each cyclic repetition. When an amplifier clips, it’s because
it’s reached its maximum voltage potential, so it starts to square off the crest of the
waveforms. This more or less turns the waveform into a square wave. Why is this bad?
Because unlike a sine wave or a triangle wave, both of which crest for only a short duration,
a square wave crests for a much longer duration. It can be described in technical terms as
exhibiting a long duty cycle. In effect, a square wave is telling the loudspeaker to move
forward in an infinitely short period of time – then to dwell there for a while – then to move
backward in an infinitely short period of time - then to dwell there for a while - then to
repeat the process. Whenever a loudspeaker has current running through its voice coil but
is not actually moving, such as at the lengthy peaks of a square wave, all of the electrical
energy is turned into heat instead of sound. Square waves will create rapid heating in even
the most robust of drivers, leading to equally rapid driver failure. Therefore, it’s better to
choose an amplifier that’s overly large for your loudspeaker but will remain out of clipping
at high levels, than one that’s too small and prone to clip.
Other attributes to consider in making a selection of amplifier type are:
•
•
•
•
•
•
•
•
Sound Quality
Reliability
Protection Circuitry
Heat Dissipation Method
Tolerance to Voltage Fluctuation
Damping Factor
Signal-to-Noise Ratio
Controls and Features
These items are briefly discussed below:
Sound Quality: Listen and compare! An amplifier that performs well in bi-amp mode with
one manufacturer’s loudspeaker may not perform as well when faced with the more
complex load of a passive crossover in another manufacturer’s loudspeaker. Make sure to
listen!
Construction Quality: Usually, this is fairly evident by taking a good look at the product,
but not always. Don’t be fooled by excessively thick front panels that hide poorly built
assemblies inside. Look inside if possible, but first make sure that the amplifier is
powered down and disconnected from the AC Mains before disassembling! An
amplifier that’s powered down and disconnected from the AC line can still cause a
shock from the energy stored in its capacitors. Be cautious! Things to note are an
excessive number of internal connectors (hardwired terminations are typically more
reliable); the quality of the pots, fans, and switches; the presence of wire jumpers and/or
cut traces on PC boards (these indicate that the design wasn’t ready for production); sheet
metal screws versus machine screws (machine screws are stronger); and the method used
to mount heavy components such as transformers and large capacitors (large bolts and
steel brackets are typically better than small bolts and gobs of silicon).
Protection Circuitry: Most modern amplifiers can sustain a dead short to their output
without damage. This is a good feature in the event that a driver shorts out, or wiring
becomes faulty. Many designs have some protection scheme against DC on the output,
which usually happens if an output transistor fails. This is another important feature as DC
will almost instantly destroy LF and HF drivers. Many amplifiers offer some sort of ‘soft’
clipping protection, which again is usually a good feature if it’s properly implemented.
Review the specifications carefully.
Heat Dissipation: Does the amplifier use forced-air cooling (i.e. fans) or passive
convection cooling? If forced air, can the fan filters be easily accessed and changed when
they get blocked with dust? If convection, can the amplifier stand up to high ambient
temperatures? Will there be a problem when multiple amplifiers are installed adjacent to
each other in equipment racks? Some manufacturers recommend putting spaces between
multiple amplifiers, especially passively cooled designs, which uses up a lot of valuable rack
space. Investigate carefully.
Tolerance to AC Mains Voltage Fluctuation: Different designs of amplifiers exhibit
widely differing behavior under fluctuating voltages. Those that are built with linear power
supplies will typically exhibit a loss of power output capability when the AC mains voltage
Community S-Series - Operation and Installation Manual - Page 31
falls below the amplifier’s nominal rating (this is sometimes referred to as a brown-out),
and they may shut down or be damaged if the AC voltage suddenly increases. Conversely,
those that are built around switching-type power supplies may be tolerant of a drop in AC
mains voltage with no loss of output capability. They may also be tolerant of an increase in
AC voltage that’s well above nominal. Many developing countries (and some parts of welldeveloped countries) routinely experience a wide range of voltage fluctuations, particularly
during times of peak demand. Certain generators that are used to power outdoor systems
may also exhibit wide voltage fluctuations. Before making a choice of amplifier type, it’s a
good idea to know as much as possible about the characteristics of the available power
where the system is to be used.
Damping Factor: This specification refers to the amplifier’s ability to dampen the motion
of the driver during intervals when the amplifier is not producing output power. When a
driver is energized, it continues to stay in motion for at least a few cycles after the power
applied to it has been discontinued, from stored kinetic energy (momentum). During these
intervals, such as in between kick drum beats, the driver is temporarily generating electric
current that flows back into the amplifier (called back EMF). If the amplifier has a high
damping factor, it will do a good job of electronically ‘braking’ or dampening the motion of
the driver. This will result is an audibly tighter and punchier sound quality compared to an
amplifier that has a poor damping factor. The effect of damping factor is especially
pronounced when the amplifier is used with large, relatively heavy cone drivers, like those
found in large-format subwoofers. This specification is typically expressed as a whole
number or a ratio such as: >200 into 8 ohms or 200:1 into 8 ohms. A higher number is
better.
Signal-to-Noise Ratio: Signal-to-noise ratio refers to how much hum and noise the
amplifier produces. It is typically expressed as either a positive or negative number; e.g.
>100 dB or -100 dB. A higher number, which indicates lower noise, is better.
Slew Rate: Slew rate refers to how rapidly the amplifier can produce output voltage when
an input signal is applied. It is expressed as volts per microsecond (V/µs). Typical
numbers range from 20V/µs to 40V/µs or higher. A high slew rate reflects an amplifier that
can more accurately reproduce the dynamic content of the input signal. However, an
amplifier with a lower slew rate may tend to sound bigger and warmer than one with a
higher slew rate. Listen and compare (see Sound Quality).
Controls and Features: In addition to the standard gain controls and front panel lights,
many of today’s amplifiers offer such features as adjustable low pass filters, remote control
of gain, remote monitoring of status, line voltage monitoring, and even full-blown DSP
signal processing. Some installations may benefit greatly from such capabilities, while
others may not need these features or cannot justify the extra cost. We recommend that
you carefully align your budget with your actual needs. In most situations, you’ll probably
benefit more by installing an adequate number of loudspeakers and amplifiers, than by
spending money on features that might not actually contribute to better performance.
S-SERIES APPLICATIONS
The S-Series loudspeakers can fulfill numerous application requirements. Some of these
are:
•
•
•
•
•
•
•
•
•
•
•
Sound Reinforcement in Houses of Worship
Theatrical Sound Reinforcement
Coffee House Systems
Music Reinforcement in Concert Halls & Performing Arts Centers
Night Club and DJ Sound Systems
Auditoria Sound Reproduction
Presentations in Hotel Meeting Rooms and Ballrooms
Health Club Exercise Music and Instruction
Corporate Training Facilities
Themed Entertainment Venues
Retail Environments
S-Series loudspeakers are equally suited for use in system designs based on distributed
speakers, exploded clusters, tight clusters, and arrays.
Community S-Series - Operation and Installation Manual - Page 32
General Application Guidelines
In choosing the right S-Series product for your application, the initial factors to consider are
the size of the venue, the style of music and speech to be reproduced, and the location(s)
of the loudspeaker(s).
In smaller venues with less demanding musical styles, one can usually achieve excellent
results with either of the two smaller S-Series models. A good rule of thumb is to consider
using a pair of the two-way S-1296 or S-1596 full-range models for venues that host up to
approximately 200 persons.
By adding a second pair of either the S-1296 or S-1596 models, venues that host as many
as 300 to 400 persons can be effectively covered. Each pair of enclosures may be
configured side-by-side or one over another, to produce additional forward radiated power.
In rooms that are particularly wide but shallow in depth, a second pair may be required
simply to obtain the necessary horizontal coverage, even if overall power is not an issue.
With its 15” cone driver, the S-1596 will provide additional low-frequency content than that
of the S-1296 which has a 12” cone driver, resulting in a richer, fuller response. However,
if either model is to be used with S-215S or S-218S subwoofers, the difference in the
response between the 1296 and 1596 will be minimal.
S-3294 and S-3594 models are true three-way designs, employing horn loaded mid-range
drivers in addition to their horn loaded high-frequency drivers. This design yields better
directional control than a two-way system. The added directionality is an asset in
reverberant rooms where it’s important to keep the sound energy off of the walls, floor and
ceiling, and/or when there’s a need to cover long distances, either indoors or out.
The larger S-3594 with its 15” cone driver will provide deeper low-frequency response than
that of the S-3294 which employs a 12” cone driver, but here again the difference in
response will be minimal if either model is used with a S-Series subwoofer.
The S-Series includes two Subwoofers; the 215S employs dual 15” drivers, while the 218S
features dual 18” drivers. Either model will add greatly increased power and extended lowfrequency response to the S-Series full-range loudspeaker(s) that it’s used with.
The smaller of the two, the 215S, is characterized by a tight, punchy sound, while the
larger 218S adds deep, dramatic low end with a rapid transient response. When using
multiple subwoofers, such as two or three on each side of the stage, it’s best to keep the
enclosures stacked or positioned tightly together for maximum mutual coupling.
If either the HIGH-PASS output on the subwoofer, or an external electronic crossover is
employed, the use of a subwoofer will free up the low-frequency power demand on the fullrange loudspeaker(s), thereby increasing output capability in the upper bass range. If an
electronic crossover is used (highly recommended), intermodulation distortion in the
amplifiers will also be reduced, resulting in maximum sonic performance.
Note: The guidelines referred to above are “rules of thumb only.” Performance
will vary based on room acoustics, room geometry (particularly ceiling height),
the location of the loudspeaker(s), the size and type of the amplifiers, and the
stylistic demands of the music and speech that are to be reproduced.
POSITIONING SUBWOOFERS
Subwoofers are far less directional than the mid-range and high-frequency loudspeakers
they are designed to augment. This is because low-frequency wavelengths are significantly
longer than mid-range and high-frequency wavelengths. A 30 Hz wave is approximately 35
feet in length and a 100 Hz wave is approximately 11.3 feet in length. These extremely
long wavelengths cause behavior that’s quite different from their shorter mid and highfrequency counterparts.
First, long wavelengths do not ‘see’ small or moderate size obstructions as obstacles; they
simply diffract around such barriers as if they’re not there.
Community S-Series - Operation and Installation Manual - Page 33
Second, the substantial length of low-frequency waves can make it difficult to distinguish
their source direction. This is why a single subwoofer can often be used successfully to
augment a stereo pair of mid-high loudspeakers, without unduly harming the stereo
separation and image.
Third, low-frequency waves tend to add together quite graciously, even if their sources are
separated by considerable distances, as long as they are in phase with each other. An
example of this in operation is the typical accentuation or build-up of low-frequency content
that is often experienced in the middle of theatres and concert halls, generated by
subwoofers placed far apart on the opposite sides of the stage.
Overall, the characteristics mentioned above imply that the location of a subwoofer is not
particularly critical, and to a certain extent that is true. However, there are several factors
to consider before you finalize your intended location4. Some of these are:
(1) A subwoofer will benefit greatly in terms of power output when it’s placed adjacent to
boundary surfaces. If located at the junction of three walls, such as on the floor or
ceiling in a corner (called Eighth Space), a given subwoofer will produce a full 9dB more
output than if that same subwoofer is located in Free Space (such as when suspended
between the middle of a floor and ceiling). If located at the junction of two walls
(Quarter Space), the subwoofer will produce 6dB more output than if suspended in Free
Space. Located on a single wall, such as the floor or ceiling, the increase is 3dB. Free
Power! What could be better? See Figure 11 for additional clarification:
Figure 11: Effect of Boundary Surfaces on Power Output
When choosing subwoofer location(s), be careful, however, not to sacrifice sonic quality
for sheer power. If the available wall or corner location results in the subwoofer being
located behind, or too close, to one or more open microphones, early feedback is likely
to occur. If the wall or corner location is too far away from the full-range
4
A thorough understanding of how low-frequency waves transmit in acoustical environments is very helpful when designing and
installing optimum sound systems. We recommend reading, “Fundamentals of Sound” and “Psychoacoustics” by F. Alton Everest in
the “Handbook for Sound Engineers” published by Howard Sams & Co.
Community S-Series - Operation and Installation Manual - Page 34
loudspeaker(s), such location may result in the subwoofer being drastically out of time
sync with one or more of the full-range speakers.
Sometimes the sound quality of a wall or corner placement is not desirable, simply due
to the room’s acoustical properties. Keep in mind that when wall and corner locations
are appropriate for use they’ll provide a tremendous increase in power output, but they
may not always be the best choice.
(2) Keeping the subwoofer(s) as close as possible to the mid and high loudspeaker(s) will
decrease phase irregularities and time smear. If the subwoofer(s) is placed too far
away from the mid/high loudspeaker(s), the listener will experience a disjointed
character to the program material, causing the musicality of the system to suffer.
(3) Although the subwoofer is not highly directional, still its acoustical output follows the
inverse square law. That is, every time the distance from the subwoofer to the listener
is doubled, the output level will decrease by 6dB. When covering a large space with
multiple subwoofers, it may be of benefit to space them some distance apart from one
another to even out the levels throughout the space. Typically, this would only be done
if the mid/high loudspeakers are also spaced apart from one another, such as in a
distributed system in a sports venue. Although this will help maintain an even level
throughout the listening space, there may be some areas that lie between two or more
subwoofers that experience a certain amount of power subtraction caused by
destructive interference. Destructive interference occurs when waveforms meet and
are partially or wholly out of phase with each other, due to unequal path lengths.
Conversely, if multiple subwoofers are located directly adjacent to one another, their power
output will add together almost seamlessly. This is known as constructive acoustic
addition. However, this may produce an undesirable hot-spot of low-frequency energy that
may be too close to a seating area.
Polarity
Unless the full-range loudspeaker(s) is stacked directly on top of the subwoofer(s) with its
cone drivers aligned with the subwoofer cone drivers, it’s likely that the phase relationship
of the two systems may not be optimal. This can be tested by reversing the polarity of one
system relative to the other, as described below.
First, however, it’s important to understand that the correct polarity of the full-range
system relative to the subwoofer is a function of their physical placement in relation to one
another. This is known as the Phase Relationship of the two systems, though Absolute
Polarity plays a role as well, which will be discussed later.
Depending on the placement of the subwoofer in relation to the full-range loudspeaker(s),
as well as the selected crossover point, the optimal response of the system might be
obtained by reversing the polarity of the full-range loudspeaker(s). The easiest way to
determine the proper polarity is to excite the system with a test signal (such as pink noise)
and to view the resultant response on an audio spectrum analyzer. If such equipment is
not available, it is also possible to determine the best polarity relationship by careful
listening.
One orientation of polarity, either normal or reversed, should result in a discernable dip
through the crossover region, due to acoustic cancellation. The opposite polarity should
result in either a flat response or a peak through the crossover region, due to acoustic
addition.
Note: When experimenting to determine the proper polarity, you can reverse the full-range
loudspeaker(s) or the subwoofer, but never both at the same time (reversing both at the
same time will not alter the phase relationship of the two systems). If there is one
subwoofer and several full-range enclosures in the same system, it will, of course, be easier
to reverse the subwoofer’s polarity to test the response. Ultimately, as we’ll see below, it’s
best to keep the subwoofer in a polarity-positive state.
If there is no discernable difference or only a very minimal difference in the measured or
audible response when the polarity is reversed, it indicates one of two things:
(1) The full-range system that the subwoofer is being used with does not reproduce
enough low-frequency output to cause either cancellation or addition with the
Community S-Series - Operation and Installation Manual - Page 35
subwoofer. This would be true if the full-range system is a very small loudspeaker, like
those that are used for front-fill and underbalcony fill.
(2) The placement of the subwoofer in relation to the full-range loudspeaker is not
optimum. Little or no response variation will occur if the physical relationship results in
an approximate ¼ wavelength of offset at the center of the crossover frequency.
The solution to (1) is for both systems to remain in positive polarity. No harm will occur if
the full-range system simply does not reproduce enough low-frequency energy to either
add or cancel with the subwoofer’s output.
The solution to (2) is to either change the physical relationship of the two systems, or to
delay one of the two systems (whichever one is positioned closer to the listeners) with a
digital delay. A high-quality, high resolution measurement system that can read and depict
phase response or impulse response would be very useful in this situation. However,
without such a system, you can determine an effective delay time by trial and error.
Simply increment the delay time in small steps (1 ms), until the action of reversing the
polarity produces maximum cancellation in one orientation and maximum addition in the
opposite. By using a digital delay, you will have preserved the phase and impulse response
of the system and you can now filter out any objectionable mid-bass overlap with an
equalizer.
If a delay is not available, it is recommended that either the subwoofer or the full-range
loudspeaker be relocated closer together, so that reversing the polarity of either the
subwoofer or the full-range loudspeaker (but not both at once) will result in a distinct dip at
crossover as discussed above.
If this cannot be done due to physical restrictions, the subwoofer and the full-range
loudspeaker should be moved further apart, again until there is a distinct dip at the
crossover frequency in one position of polarity. It may take some trial and error to
determine the optimal physical relationships.
C-TIP: It’s a good idea to experiment with different loudspeaker locations by conducting
listening tests before you finalize the locations (especially important in permanent
installations). Make sure to use live microphones and live instruments (if applicable), as
well as track playback. Choosing the physical location of the loudspeakers in the room is
always the most important part of any successful system installation.
Note that in some acoustical environments, the system may sound better when the phase
relationship is non-optimum resulting in a dip at crossover, compared to optimum phase
where the crossover region is accentuated by the overlap of the subwoofer and the fullrange speaker(s). However, this is not the best way to achieve the sound that you’re
seeking. The proper course of action is to equalize (EQ) the peak at crossover with a
parametric equalizer until the response is flat, or until you’ve achieved the tonal response
you desire (we’ll explain why below).
Alternatively, you might insert a high-pass filter in the full-range system (typically at 80 –
100 Hz with a 12dB/octave slope), so that the overlap with the subwoofer is reduced in
magnitude.
A third technique is to increase the slope of the crossover to 24 dB per octave or 48 dB per
octave, if the crossover has such capability, thereby reducing the bandwidth of the
spectrum in which the two sources overlap.
There’s an important reason for taking one or more of the measures discussed above. If
that nice-sounding response dip at crossover is in fact due to phase cancellation, it means
that the drivers and amplifiers will be working harder than they should to produce less
sound pressure level than they are capable of, due to the acoustic cancellation taking place.
All that cancelled energy uses power unnecessarily!
Instead of putting the two systems out-of-phase to get the sound you want, if you
attenuate the peak at crossover with any of the methods described above5, you are
5
The three corrective methods referred to in the text, equalizing, high-passing, and increasing the slope of the crossover,
are all various implementations of equalization.
Community S-Series - Operation and Installation Manual - Page 36
reducing the power that’s required to obtain a given sound pressure level. This will result
in more available power, more headroom and less demand on the drivers, all of which
lowers the potential for distortion and damage under high power conditions.
Now that you’ve chosen the final physical locations for your full-range loudspeakers and
subwoofers, established their optimum phase relationship, and brilliantly EQ’d any
crossover peaks, you’re almost ready to permanently wire the system. But first read the
section below on “Absolute Polarity.”
Absolute Polarity
Quite a bit has been written about absolute polarity, particularly in regard to studio
recording and hi-fi sound reproduction. The subject is, however, often ignored in the field
of sound reinforcement. Essentially, positive absolute polarity refers to configuring the
system so that upon the first cycle of excitation by the source material, the driver(s) moves
forward toward the listener, thereby producing a positive wavefront. For example, at the
instant of impact when the head of the kick drum moves outward towards the microphone,
the speaker cones will also move outward.
Obviously, the polarity integrity of the entire signal processing chain must be maintained
for this to occur. Is absolute polarity audible? Should you be concerned? Yes, it is audible
and though subtle, it makes a big enough difference to warrant taking the time needed to
insure that the signal chain is polarity-positive throughout. You’ll hear an improvement in
sonic impact, especially in the lower frequencies.
We recommend that absolute polarity be kept positive in all low-frequency devices
whenever possible. This can be checked with a small handheld style polarity response test
unit, available from numerous manufacturers.
Although it’s easy to simply reverse the polarity of the subwoofer to determine its best
polarity relationship to the full-range loudspeaker system, if the best position turns out to
be reversed we recommend that you instead reverse the full-range system(s) so that the
subwoofer(s) can remain in a state of positive absolute polarity.
SYSTEM EQUALIZATION
There are numerous schools of thought on proper equalization techniques. Some believe
that using anything more than a touch of equalization is wrong, often attributing their
concerns to ‘phase shift’ from the equalizer. Others believe the opposite. Some say
equalization can’t be performed correctly without advanced instrumentation, while others
say it must be done by listening; after all, the end product isn’t a graphic display, it’s an
audible event.
One engineer would never equalize a sound system with a parametric equalizer, while
another would not use a graphic equalizer. A well known sound designer once stated that
when the equalizer is switched in and out, if he couldn’t hear the difference, he considered
the system to be properly tuned. As these examples illustrate, there are widely varying
beliefs on the subject of equalization.
Instead of touting a particular philosophy, let’s approach the practice of equalization by
looking at the transfer function of the loudspeaker and room together. We can do this with
a two-port FFT analyzer.
For the sake of this short discussion, let’s assume that the loudspeaker we’re using exhibits
a perfectly flat frequency and phase response in a free field environment. We’re going to
assume this because it will help to illustrate the point of the discussion. The fact that few,
if any, loudspeakers are perfectly flat in a free field environment is not of paramount
importance, nor is the fact that many high quality loudspeakers can actually be equalized to
be almost perfectly flat, if one wants to go through the exercise of doing so. The point here
is to illustrate the principal of precisely correcting for room resonance.
Community S-Series - Operation and Installation Manual - Page 37
So here we have a loudspeaker installed in a room. We already know that this loudspeaker
exhibits a flat response in a free field environment, such as outdoors or in an anechoic
chamber. But what happens when it’s installed in a room?
Logic dictates that whatever changes occur to the response of the loudspeaker in the room,
are dependant entirely on the effect of the room (unless, of course we wired the
loudspeaker wrong, or broke it in transit…which we didn’t).
Now as we listen to our loudspeaker, we hear things we didn’t hear in the free field
environment. It sounds bass heavy. It sounds like there’s a buildup of energy somewhere;
say around 300 Hz. We also hear something happening at about 600 Hz. What do we do?
Let’s measure it. Let’s assume we have a narrow band, a high resolution FFT-based6
measurement instrument and a perfectly flat microphone (these do actually exist). Should
we measure it nearfield, say about 1 meter away? Why not? Somewhere we heard that’s a
good thing to do.
We place the microphone about 1 meter from the loudspeaker and we look at the response.
It’s quite flat. Not like it looked when we measured it outdoors, but not all that different.
Overall, the lower frequencies exhibit a gradual rise in amplitude as they drop in frequency,
but there’s also some ‘rolling hills’ up to about 800 Hz.
We grab our graphic equalizer and try to smooth out these rolling hills and the rise in the
bass response. A cut at 63 Hz merely puts a hole in the response at 63 Hz; it doesn’t fix
the rolling hills. But the loudspeaker does sound less bass heavy when we run the music
track. More cuts at 125 and 250 again help it to sound less bass heavy, but we can clearly
see we’re ‘chopping up’ the response curve. Maybe these minimalist guys are right….too
much EQ really chops things up! Too bad there’s not a filter on this thing that produces the
inverse of the whole response shape.
Let’s try moving the mic to the mix position. That’s seems to be a good idea. Put the mic
where the sound operator is.
Wow. Now there’s a whole new picture. The holes from the graphic can barely be seen
anymore. Instead, there’s a big bump at 362 Hz and again at 725 Hz, and the whole low
end is even more accentuated.
We try using the graphic to flatten the response. We try for a long time, but no
combination of filters will flatten the low end. Pulling down 315 takes part of the 362 Hz
bump out, but not all of it. Pulling down 400 just puts a hole above the bump at 362 and
makes the bump look even bigger than before. Same problem at 725 Hz. “This isn’t
working! It must be true… you can’t really EQ a room.”7
Someone says, “Let’s try this parametric equalizer instead.” You’re ready to do anything.
After setting it up, you’ve found it has a shelving filter with an adjustable turnover
frequency. You try cutting it 8 dB and the whole low end quickly flattens, except for the
362 Hz bump. But the slope’s not quite right. There’s still a quick rise around 900. You
move the turnover frequency up to 900. Like magic, the whole low end is now flat except
for the bumps at 362 and 725. Engaging a bandpass filter, you dial up a peak of 4 dB
making the bandwidth quite narrow. In a few seconds, you’ve easily centered the peak
squarely on the bump at 362 Hz. Now you cut it and fiddle with the Q. In a few more
seconds, the bump is gone. No trace.
You repeat the process at 725. Again it’s gone without a trace. But this has to play havoc
with the phase, doesn’t it? Something has to be wrong. It’s too easy.
The guy who owns the FFT tells you that because you’re looking at the transfer function of
the loudspeaker in the room, you can also see the phase response if you want to. He
pushes a few buttons and there on the screen is a phase response trace, along with the
frequency response trace. It looks remarkably flat from about 200 Hz up to 1 kHz or so.
You bypass the equalizer and the bumps are back, along with the big rise in low end.
Remarkably, the phase trace now shows two wiggles, dead centered on the 362 and 725
6
FFT is an acronym standing for Fast Fourier Transform and is based on the Discrete Fourier Transform, a mathematical algorithm
defined by French mathematician Jean Fourier. FFT measurement instruments are vitally important to the study of sound and
vibration.
7
No matter what technique you use you can’t, of course, EQ a room; you can only EQ the sound system in the room. But much of
the world refers to the process of equalizing a system as ‘room-tuning.’
Community S-Series - Operation and Installation Manual - Page 38
bumps, and an overall drop that looks like the inverse of the low-frequency rise. You feel a
little like Alice in Wonderland. When the equalizer was switched in, the filters actually
improved the phase response! You’ve got to get your hands on one of these FFT things,
and soon.
###
OK. Let’s put this event into more scientific terminology. Here’s what’s happening: The
loudspeaker is transferring its acoustic energy into the room. This energy presents itself in
the form of pressure waves, causing cyclical pressure and rarefaction in the room’s
atmosphere. Under excitation, the volume of air in the room begins to resonate, as
confined volumes of air tend to do. This is not a particularly large room, so its primary
resonant frequency is quite high at 362 Hz8. The second harmonic of that frequency is also
present at 725 Hz. Going back and looking more carefully, one would probably see
additional third order harmonic resonant modes, and possibly a sub fundamental mode as
well.
Other parts of the room, particularly if it’s a complex architectural design, might exhibit
their own resonant modes at different frequencies, such as in the underbalcony area.
But why was the phase response improved merely by applying frequency equalization? The
answer is simple. The peaks in amplitude at 362 and 725 Hz that were removed by the
equalizer were caused by systemic resonance (the ‘system’ being the sum of the
loudspeaker and the room). Because it takes time to complete a period of resonance, this
time period alters the systemic phase response as well as the frequency response. If one
could precisely cancel out the variation in phase response with an FIR filter, the result
would be the inverse, or a perfectly flat frequency response curve. It’s a wholly organic
process in which phase response and frequency response are intrinsically linked.
The ideas and techniques described above can be extended to arrays, clusters, delay
systems and distributed systems. Managing the various zones of a large-scale sound
system is, of course, much more complicated, but the basic techniques remain the same.
Properly applied, equalization can be a powerful tool with benefits extending even into the
time domain, as we’ve illustrated above. The potential for radical improvement in both the
phase and frequency response, through the use of precision equalization, can even make a
large, reverberant room sound significantly ‘smaller.’ This is because the reverberant field
in a room is typically longer and higher in amplitude at frequencies where it exhibits
excessive resonance, than throughout the remainder of the audible spectrum. By reducing
the energy from the sound system at those resonant frequencies, the room may no longer
sound particularly reverberant at all.
When using precise measurement equipment, additional useful processes can be brought to
bear. For example, instead of flattening the ancillary underbalcony and over balcony
systems, first look at the spectral content of the energy that’s arriving in those areas solely
from the main array(s) located far forward in the room. Typically you’ll see that there’s
already too much low-frequency content. You might also see a local zone resonance that
wasn’t noticeable in the forward section of the room. And there might be an excess of
energy at some particular mid-spectrum frequency.
By shaping the delay system to add only the portion of the spectrum that’s lacking from the
main house array(s), and precisely delaying it to within a millisecond of the true
propagation time, these ancillary systems can wonderfully improve the listener’s experience
in what are often called the ‘cheap seats.’ Additionally, when an ancillary delay system is
additively aligned as described above, its overall energy contribution is lower and therefore
it’s far less prone to reflecting energy back into the room, which could quite possibly
corrupt the sound in the forward seating areas.
This ‘additive’ technique can be applied to front fill loudspeakers, down fill loudspeakers,
and any other area where multiple systems overlap in a shared acoustic space.
Precedence (The Haas Effect)
The Haas Effect, or precedence effect, is named after Helmut Haas who first described it in
his doctoral dissertation. It states, in part, that one sound source may be as much as 10
8
In a real life situation the primary room resonant frequency would tend to be much lower, but it’s easier to illustrate the principal
in a range where the graphic equalizer has more available bands.
Community S-Series - Operation and Installation Manual - Page 39
dB greater in intensity than another, but will not be identified as the location that the sound
is coming from, if it arrives later than the lower intensity source.
This effect can be used to make underbalcony, overbalcony, and other delayed
loudspeakers acoustically ‘disappear,’ drawing the listener’s attention to the stage rather
than to the ancillary delay speaker. The idea is to first find the correct delay time that will
align the output of the ancillary loudspeaker with the output of the primary source, then to
increase the delay time of the ancillary loudspeaker to take advantage of the effect.
If the correct delay time is accurately identified within a range of one to two milliseconds,
the additional delay required to take advantage of the Haas Effect can be as little as two to
three milliseconds. The exact value should take into account the overall distance between
the two sources. Greater distances require slightly longer additional delay times in order to
compensate for variances in the velocity of sound as the temperature in the environment
changes.
Why not equalize by listening? After all, the end product is sound!
That’s true, but you’re probably not going to listen to swept sine waves, you’re more likely
to be listening to music. Even if you’ve trained your hearing to a very fine degree and you
possess perfect pitch, you can easily miss room resonant modes if the music you’re
listening to is in one musical key, and the room resonance happens to lie outside of that
key.
While some rooms exhibit broad resonant peaks that are readily detectable by listening,
others have quite narrow ones that can be easily missed. Typically, the bandwidth of room
resonance is often close to one-third octave, hence the development of the third-octave
equalizer. Unfortunately, most rooms aren’t cooperative enough to exhibit resonance that
falls precisely on ISO frequency centers, which makes the third-octave equalizer an
imprecise correction tool.
Even if a room resonant mode does fall on an ISO frequency center, its resonant frequency
will shift upwards when the room fills with patrons and the volume of air is reduced by the
displacement of solid bodies. An FFT type analyzer will let you see this effect, and a
parametric equalizer will allow you to adjust for it. With an FFT you can even use music as
your ‘test tone’ to continually measure the changes in the room response during a
performance, because a two-port FFT set to take continual measurements in the transfer
function mode doesn’t care what the signal is; it’s just as happy resolving music as it is
resolving pink noise, swept sine waves, or other sources. Noise just happens to provide
much faster results, because of its broadband nature.
RIGGING AND MOUNTING S-SERIES ENCLOSURES
One of the most important tasks the installer faces is the rigging and mounting of the
loudspeaker system. S-Series loudspeakers have been designed with rigging and mounting
in mind; thus, there are numerous ways to safely and easily install S-Series loudspeakers in
optimal locations in the venue.
SAFETY FIRST!
There is no way to overemphasize the importance of safety. But we’ll try. The kinetic
energy of an 80 lb. loudspeaker enclosure dropping from 30 feet and contacting a concrete
floor is enormous. The loudspeaker will be traveling at a speed of about 35 miles per hour
at the time of impact. Imagine if you were seated under it. You might have a better
chance of surviving a dynamite blast.
If you do not have knowledge of safe rigging practices and experience in applying them,
contact a qualified rigging contractor to design and carry out the installation! Rigging that
is improperly installed is like a time bomb; sooner or later it will fail, with the potential to
cause serious injury, paralysis, dismemberment, or loss of life. Even if no one is directly in
the line-of-fall of a failed suspension system, the panic that might ensue could in itself
cause multiple deaths. Do not take chances!
Community S-Series - Operation and Installation Manual - Page 40
RIGGING GUIDELINES
The following guidelines on rigging are not intended as a comprehensive rigging manual,
nor are they meant to replace the knowledge of safe rigging practices that might be
obtained from receiving professional training on the subject. These guidelines are intended
only to provide basic safety information, and to call your attention to some commonly made
mistakes. Books, seminars, and hands-on courses are available that teach safe rigging
techniques; we highly recommend that you seek them out if you do not already possess the
requisite knowledge and experience to perform rigging work safely.
DISCLAIMER: Community warrants that its loudspeaker systems and its optional
mounting and rigging hardware have been carefully designed and tested. Community
loudspeakers may be safely mounted and rigged when each loudspeaker model is
installed with Community-manufactured optional mounting and rigging brackets
specifically designed for use with that particular model of loudspeaker. This warranty
applies only for use under normal environmental conditions,9 and when all loudspeakers,
component parts, brackets and hardware are assembled and installed in strict accordance
with Community’s installation guidelines contained herein. Beyond this, Community
assumes no further or extended responsibility or liability, in any way or by any means
whatsoever. It is the responsibility of the installer to insure that safe installation practices
are followed, and that such practices are in accordance with any and all local, state,
federal, or other, codes, conditions, and regulations that may apply to, or govern the
practice of, rigging, mounting, and construction work in the relevant geographic territory.
Any modifications made to any parts or materials manufactured or supplied by
Community shall immediately void all pledges of warranty or surety, related in any way to
the safe use of those parts and materials.
1. Load Rated Components
All components of the rigging system such as wire rope, shackles, chains, eyebolts, etc.,
must be load rated. This means that they are marked or rated with a Safe Working Load
(SWL) or Working Load Limit (WLL). All such items should be designed and
manufactured by reputable companies that regularly supply the theatrical and industrial
rigging industries, such as The Crosby Group, or equivalent. It is strongly recommended
that you source your rigging items from an industrial supplier or specialty rigging house,
never from a hardware store. Items found in local hardware stores are often poor copies of
the original designs and may not be safe, as well as typically being more costly than items
purchased from an industrial supplier. By planning ahead, you will not be in the
uncomfortable position of having to delay the work if you can’t locate a shackle or eyebolt
at the last minute.
2. Safety Factor
No component in a rigging system should be stressed to its maximum load rating. A
suitable Safety Factor or Design Factor must be determined and applied, so that every
component in the rigging system has reserve load capacity. The manufacturer’s stated
SWL (Safe Working Load) or WLL (Working Load Limit) is the quotient of the component’s
ultimate strength, or breaking point, divided by the manufacturer’s stated safety factor. If
the safety factor is not stated on the component or in the manufacturer’s technical
specification sheet, the component should not be used, as its ultimate strength is unknown.
In addition to the manufacturer’s rated Safety Factor, the prudent installer will determine
and apply an additional Safety Factor to insure that the suspension system is installed in a
manner that cannot fail under the prevailing conditions.
Safety factors may be regulated by local, state, federal or international agencies and
therefore may vary based on your geographic location. Safety factors typically assume
normal environmental conditions; additional consideration must be given when unusual
conditions are encountered, such as in corrosive marine environments (e.g. loudspeakers
9
Normal Environmental Conditions are defined as the following: -15 to 55º C, no excessive or unusual air-born contaminants or
pollutants present, no chemicals or contaminants coming in direct contact with the product, no excessive vibration or wind loads.
Community S-Series - Operation and Installation Manual - Page 41
mounted on a cruise ship or in a venue located near sea water), or in conditions involving
high-vibration, high wind-loads, or other unusual conditions. A common safety factor is a
6:1 ratio; however many theatrical rigging companies voluntarily work at a 7:1 ratio or
higher. A 10:1 ratio is required in most countries that are members of the European Union.
At a 10:1 ratio, this means that a component rated at 10,000 lbs of ultimate strength
should never be subjected to a load greater than 1,000 lbs. The de-rated value of 1,000
lbs should take into account the additional force of dynamic loading, such as when a
motorized hoist starts and stops. Such dynamic loading can easily exceed 200% of the
static load and is dependent on the hoist design, how close to capacity it is loaded, the
length of the cable or chain, and the elasticity of the supporting structure.
Seismic Considerations
Seismic events (earthquakes) can cause great dynamic loading of a rigging system. In the
case of strong quakes, which occur regularly in some regions, a rigged system may merely
sway back and forth with no damage, or it may be subjected to many times its static load
rating, particularly in the case of unequal loading of a multi-part suspension system due to
uneven roof or beam movement. It’s also possible that one loudspeaker rig may contact
another rig or a lighting truss, during the quake. The results cannot be predicted because
seismic events occur with differing forms of wave motion at varying axes to the suspended
system. An earthquake might produce long, rolling waves in one axis then later, an
aftershock on the same day could produce short, violent waves in another axis.
Aging of Components
Over time, hardware components used for rigging will degrade, causing them to lose some,
or even much, of their load capacity. Factors include strain, oxidation, exposure to
corrosive or acidic atmospheric conditions, exposure to water and chemicals, exposure to
UV light, and metal fatigue. In consideration of long-term durability, a high safety factor
should always be chosen, particularly when future conditions cannot be clearly foreseen
(which is almost always the case).
3. Safety Cable
All loudspeakers, lighting instruments and any other object that is rigged or suspended in
any way (this includes the use of wall brackets) must be fitted with one or more safety
cables. Safety cables are a backup method of suspension intended to keep the rigged
object in the air, in the event that the primary suspension system fails.
Safety cables must be sized appropriately for the loads they will carry, and should be
attached to a different point or points on the wall, ceiling, truss, frame, bumper, or other
support device, than that of the primary suspension system. They should also be attached
to a different point or points on the objects that are being suspended.
Shock Loading of Safety Cables
A safety cable must have as little slack in it as possible so that if the primary suspension
system fails, causing the load to switch from the primary suspension to the backup safety
cable, the shock will be minimized. An object that falls and is caught up short places
enormous strain on its safety cable. A 100 lb loudspeaker falling just several inches, can
create a shock load as great as 500 lbs. It’s difficult to precisely calculate the strain of a
shock load unless you know the elasticity of the safety cable as well as all other
components in the suspension system. Suffice it to say that this is rarely known with
accuracy. Therefore, in order to insure safety, the total potential stress subjected to the
safety cable and any components that are used with it, should always be a small fraction of
the ultimate breaking strength of the weakest component.
Community S-Series - Operation and Installation Manual - Page 42
4. Load Angles
This is an area that is often misunderstood, so let’s clear it up. Whenever an object is
suspended from one point, it has no choice but to hang directly below that point of
suspension; in other words at a zero degree angle to the suspension point. When an object
is suspended from more than one point, the points may or may not be at zero degrees to
the suspension point. When the suspension points are not at zero degrees to the object,
they form a bridle. As the angle of the bridle increases, the force through each leg of the
bridle also increases (see Figure 12 below). A high angle bridle can produce forces in the
suspension legs that are many times the weight of the suspended object. This is
counterintuitive, as most people’s understanding of physics would suggest that the object
cannot produce a greater load than that of its own weight. Not true. For example, a 100
lb. object can produce 300 lbs. of force at a bridle angle that may not appear dangerous to
the untrained observer. At very steep angles, the load can far exceed the rating of even
the most robust rigging components, in addition to placing an enormous compression or
expansion force on the object itself (depending on the direction of the bridle). Therefore,
steep bridle angles are to be avoided under all circumstances.
Figure 12: Load Angles
Even more dangerous, is the practice of reeving a suspension cable or sling through two
shackles or eyebolts, forming a type of basket hitch (see Figure 13). This again increases
the force through each leg, as well as significantly increasing the loading on the shackles.
It also allows the load to easily tip or shift its weight in the hitch. It should always be
avoided.
Figure 13: Never Reeve Cables!
Community S-Series - Operation and Installation Manual - Page 43
5. Wire Rope Clips
Wire rope clips, sometimes called “Crosbys” after one manufacturer, should always be of
the drop-forged type, never of malleable steel. They must always be installed in
accordance with the manufacturer’s instructions and specifications. Although specific
instructions will vary depending on the design of the clips and the diameter of the wire
rope, they will always include the number of clips, the length of the turn back, the spacing
of the clips, torque of the nuts, and the orientation of the U-bolt. Using too few clips, too
little turn back, spacing the clips improperly, over-tightening or under-tightening the nuts,
and improperly orienting the U-bolts can all cause catastrophic failure. Overlooking the
importance of re-tightening the nuts after load is applied can also lead to failure. The
prudent installer will be prepared in advance, carrying a calibrated torque wrench in the
toolbox.
As a general rule there should never be less than three wire rope clips on wire rope of 1/8”
to 1/4” in diameter, and more on larger diameters. Clips should be evenly spaced and the
U-bolts should always be oriented so that they are on the dead end of the wire rope, as
they can cause damage to the live end. Wire rope that’s properly terminated with highgrade rope clips will result in approximately 80% of the strength of the wire rope itself.
Example: If a specific wire rope has a rated Working Load Limit of 1000 lbs., that rating will
be reduced to 800 lbs. when the wire rope is terminated with wire rope clips. Conversely,
Nicopress fittings (see below) are capable of providing terminations that are equal to the
strength of the wire rope itself.
6. Nicopress® Fittings
Like wire rope clips, Nicopress fittings are used to terminate wire rope ends. They consist
of an oval sleeve of malleable metal (typically copper, aluminum or stainless steel) that’s
pressed onto the wire rope with significant force using a specially designed tool. Nicopress
is the proprietary brand name of one manufacturer, but has become nearly a generic name
among riggers. As with wire rope clips, fittings of similar design to Nicopress are available
from multiple manufacturers of varying quality. If high grade fittings are properly installed
with the correct tool (this is a big “if”), they will form a termination that is equal in strength
to the wire rope itself. As with all rigging components, it is highly recommended that you
purchase such fittings and tools from professional supply houses, not from local hardware
stores. Genuine Nicopress tools come equipped with a calibration gauge to insure that the
tool is performing properly on every fitting over time.
7. Shackles
Only industrial grade load-rated shackles should be used to attach wire rope or fabric slings
to hang points. The use of rapid links, Quicklinks, clip locks and other non-rated hardware
items should absolutely be avoided. Shackles and other high-strength forged components
must never be dropped onto hard surfaces, such as concrete. If a shackle is dropped more
than a foot onto concrete, discard it. The impact of the fall could cause the metal to
crystallize, leading to early failure.
8. Eyebolts
Eyebolts are often used to suspend single loudspeakers, arrays, and clusters of
loudspeakers. Some of Community’s S-Series rigging accessories are designed to utilize
eyebolts. Eyebolts are available in several styles and materials. Some of the most
common are:
•
•
•
Formed steel plain eyebolts;
Forged steel plain eyebolts;
Forged steel shoulder eyebolts (sometimes called “machine eyebolts”).
For loudspeaker rigging, only rated forged steel shoulder eyebolts purchased from a
reputable manufacturer, should be utilized. Community offers this style of eyebolt at a
reasonable cost.
The SWL or WLL rating of any eyebolt is based on a straight line pull. If the load angle
varies from that of a straight line, the load rating rapidly decreases. At 45° the eyebolt has
Community S-Series - Operation and Installation Manual - Page 44
only 30% of its rated strength. At 90º it is de-rated to only 25%. Use at angles steeper
than 45° is strongly discouraged. Such use would be permissible for breasting back a
loudspeaker to alter its downward angle, where the breast line is not part of the suspension
system nor is it considered to be the safety cable. Vertically rigging a loudspeaker from
eyebolts placed into its side surfaces (90º) must always be avoided. When eyebolts must
be angularly loaded, it’s vitally important to design any multi-point suspension installation
with a low bridle angle (see Load Angles), and to de-rate the eyebolt accordingly.
Proper Tightening of Eyebolts
If the shoulder eyebolt is not properly tightened, its angular load bearing ability will
significantly decrease, leading to rapid failure. Make sure to follow the eyebolt
manufacturer’s instructions for proper tightening. The prudent installer will be prepared in
advance, carrying a calibrated torque-wrench in the toolbox and a way of coupling it to the
eyebolt. We recommend cutting a groove into the sides of a large socket, as a means of
using the torque-wrench to tighten the eyebolt.
Eyebolt Orientation
A shoulder eyebolt should only be angularly loaded in the long axis of the loop of the eye; it
should never be laterally loaded. Loading against the axis of the eye can cause breakage at
even very low force. After tightening the eyebolt, if the eye is not aligned axially to the
line-of-force, a shim or washer should be installed to re-position the eye. The eyebolt
should never be loosened or over-tightened as a way of aligning its axial orientation. If
you’re equipped in advance with a variety of washers and shim material, you’ll be able to
safely install eyebolts quickly and painlessly.
Lastly, never reeve slings in a basket-type hitch through eyebolts (see Figure 14 below).
Doing so will radically increase the strain on the eyebolts and on the slings from vector
loading, as well as permitting the load to tip or shift.
Figure 14: Never Reeve Cables!
9. Threaded Fasteners
Threaded fasteners are often used in rigging and mounting systems. As with eyebolts,
many of Community’s optional mounting brackets, yokes, and rigging plates utilize
threaded fasteners. The fasteners that come with each Community rigging kit are load
rated to a sufficient strength to be safe when used within their specified parameters. If
replacement bolts are needed, or if additional bolts are required for mounting a bracket to a
beam, wall, or ceiling etc., such bolts should be purchased from a reputable manufacturer
with a minimum Grade 5 rating. On hex-head bolts this can be readily identified by looking
at the head. A Grade 5 bolt will be marked with three lines; a Grade 8 bolt, which is even
stronger, with six lines. Allen drive fasteners are often made of high-strength steel (Grade
5 or better) if they are purchased from an industrial suppler. As with any other rigging
component, check the rating on the box or the manufacturer’s specification sheet to be
sure.
Community S-Series - Operation and Installation Manual - Page 45
10. Support Points & General Practices
A vital part of planning the mounting or suspension system is to first determine the
strength of the building’s support points. Nothing should be assumed, even for the lightest
loads. A ten pound loudspeaker falling from ten feet can maim or kill just as readily as a
heavy loudspeaker array falling from thirty feet. The services of a registered structural or
professional engineer should be employed to determine if the materials and design of the
supporting structure are adequate to support the intended load, and how to best install
mounting brackets or derive suspension points.
Fabric Webbing, Slings, and Spansets
Fabric webbing, fabric slings, and polyester Spansets can be very useful to the rigger. They
are strong, lightweight, and do not have stray wires on their ends that can cut fingers like
wire rope slings. They’re particularly useful as a means of securing a personal safety
device such as a climbing harness, when working at elevation. That said, be cautious of
using them in permanent installations as they are far more prone to damage by fire than
their steel counterparts.
Fasteners
As a general rule, lag bolts driven into wooden beams should be avoided whenever
possible, as they can pull out as the wood ages or swells due to changes in temperature
and humidity. Safe riggers will instead utilize machine bolts of Grade 5 ratings or higher,
rated beam clamps, brackets fabricated and welded by certified welders, wire rope wrapped
around beams with cushioning materials, and so on.
Certain wooden beams, or trusses, made of many laminations (often called Glue Lams) are
intolerant of holes. These beams are commonly used in modern construction, particularly
in tilt-up concrete industrial buildings. Drilling a hole through such beams can set up
internal fractures, resulting in total failure of the beam. Alternatives to drilling include
fabricating steel brackets to surround the beam, or wrapping the beam with a steel sling
and fabric cushions, to derive a hang point.
Concrete expansion bolts, such as Hilti Kwik-bolts or equivalent, can provide an excellent
means of attaching moderate loads to concrete surfaces. However, as they rely on an
expanding wedge to obtain their strength, they must always be used in strict accordance
with the manufacturer’s instructions. Such instructions specify the diameter and depth of
the hole, the composition of the concrete, permissible spacing of the anchors, and the
torque of the bolts. As a general rule, they should only be used for sheer loads, not tension
loads.
11. Liability
When you install a loudspeaker that is mounted or suspended over people’s heads, it is
your responsibility and yours alone to insure that the installation is performed in a safe
manner. Never take the word of someone who tells you, “That beam is safe to drill into,”
or “This point can handle the load,” or “I’ll take responsibility if anything happens.” To
paraphrase Harry Donovan from his excellent book on safe rigging practices entitled
Entertainment Rigging, ‘How is it going to sound to the jury at your manslaughter trial
when you use such statements by others as your defense?’
Never do anything you aren’t 100% sure is safe. If a manufactured product looks poorly
designed and built, it probably is poorly designed and built. If you aren’t absolutely sure
where the wire rope came from or how strong it is, don’t touch it. If the bolt looks too
flimsy to hold the load, it probably is too flimsy. Always use your best judgment, just as
you do when driving at high speeds in traffic. The life you save may be your own.
Community S-Series - Operation and Installation Manual - Page 46
S-SERIES RIGGING AND MOUNTING HARDWARE
Below are descriptions of mounting brackets and suspension kits manufactured by
Community for use with S-Series loudspeakers. In this section the terms “suspension” and
“fly” mean the same thing: to elevate the loudspeaker enclosure above the ground surface.
IMPORTANT: All rigging fittings should remain sealed, otherwise air leaks will occur in the
enclosure that can compromise the low-frequency performance with distortion and reduced
output.
WARNING: S-Series rigging fittings are rated at a Working Load Limit of 100 lbs (45.4kg)
with a 10:1 safety margin. No single rigging fitting should ever be subjected to a load that
is greater than 100 lbs. Failure to heed this warning could result in injury or death!
1. Seat Track Kit: STKIT
A Seat Track Kit is available that fits all models of SSeries full-range loudspeakers. Designated the STKIT,
the kit provides a safe and convenient means of
suspending a single enclosure.
By purchasing multiple kits, one enclosure may be safely
suspended over another.
Both M10 Metric and 3/8-16 Unified Course (UNC)
threaded fasteners are included with each STKIT.
Because these fasteners have nearly identical threads, it
is critically important that you use fasteners with the
proper thread pitch for the S- Series of loudspeakers.
The proper fasteners are the M10 metric fasteners. Do
not use the 3/8-16 UNC fasteners.
All parts in the kit are engineered to provide a high
margin of safety. Each Seat Track Channel is load rated at 350 lbs with a 15:1 Safety
Factor. The channels are manufactured of milled high-strength aluminum and are anodized
black. (However, the highest weight to consider at any one point is the weakest link – the
threaded insert.)
No hardware is provided to attach to the fittings in the Seat Track Kit. Such hardware must
be supplied by the installer, and should be rated for the weight load of the enclosure(s). If
multiple enclosures are suspended one above the other, it is the installer’s responsibility to
insure that the combined weight load does not exceed the Working Load Limit on any one
rigging fitting. This is particularly important if the enclosures are angled downward, as
most or all of the weight may be supported by the rear points only.
Hardware fittings that mate with the Seat Track Channel are available from numerous
entertainment rigging suppliers. Be sure to purchase or specify only such fittings that are
rated for use overhead. The installer is solely responsible for determining if all rigging
components that are used to suspend the enclosure(s) are adequately sized and rated, and
if the structure they are suspended from is capable of safely supporting the aggregate
weight load of the enclosure(s).
STKIT Parts List
Aluminum Seat Track Channels (4)
8 x 1” Flathead Phillips Drive Deep Thread Screws (4)
M10 x 40mm Flathead Allen Drive Screws (4)
3/8-16 x 1.5” UNC Flathead Allen Drive Screws (4)
The installer must supply all other hardware for the installation.
Community S-Series - Operation and Installation Manual - Page 47
STKIT Assembly Instructions
CAUTION: Before assembling the Seat Track Channels to the loudspeaker enclosure, note
that the kit is supplied with both 3/8-16 Unified Course and 10mm Metric fasteners. These
fasteners are very similar but they are NOT identical. It is critically important that you use
fasteners with the proper thread pitch. All S- Series loudspeakers use the M10 metric
fasteners. DO NOT USE THE 3/8-16 UNC FASTENERS! It is very easy to mistake one
thread pitch for the other.
1.
To assemble the Seat Track Channel to the loudspeaker enclosure, first remove the
factory supplied flat-head Allen screws from the top of the enclosure.
2.
Next, place a Seat Track Channel over each rigging fitting in the enclosure. Orient the
Seat Track Channel so that it is not overhanging the edges of the enclosure, and align
it so that it’s parallel to the enclosure side (see Figure 15). Using a fastener with the
proper thread pitch, thread each fastener into the rigging fitting in the enclosure until it
is finger-tight. If a fastener does not thread easily into the fitting in the enclosure, it
may be of the wrong thread pitch. Do NOT force it with a wrench! Check the threads
to make sure they are correct. You can do this by comparing the supplied fastener to
the one that you removed from the enclosure. If the threads are identical, you will not
be able to see any light between them when they are nested together. If you can see
any light at all between the two fasteners when the threads are placed next to each
other, they are not identical!
DANGER: Use of the wrong threaded fastener will result in thread failure under load, which
can cause damage to property, serious injury, or death.
3.
Tighten each fastener to a torque of 15 foot-lbs using a torque wrench. Do not
overtighten.
Note: Allen wrenches with 3/8” and ½” socket fittings, designed to attach to a ratchet
or torque wrench, are readily available at tool stores.
4.
Now, using an electric screwdriver, insert one 8 x 1” flathead Phillips screw into each of
the small holes in the Seat Track Channels. Tighten until snug. Be careful not to
overtighten, as the screw will break under too much torque. The purpose of these
smaller screws is only to keep the Seat Track Channel from rotating under load.
5.
After attaching appropriate mating hardware to the Seat Track Channels, you can now
lift the enclosure a foot or two off the ground. Check to make sure all fasteners are
tightened securely, and then bring the enclosure to trim height.
Using More Than One Enclosure
Additional Seat Track Kits may be used to suspend one enclosure over another. This is
accomplished by attaching one set of Seat Track Channels to the bottom of the upper
enclosure, and a second set of Seat Track Channels to the top of the lower enclosure.
The two enclosures may then be joined together by using various hardware fittings that
mate to the Seat Track. Such hardware includes swivel fittings, tandem swivel fittings, and
other mating devices that are readily available from theatrical rigging suppliers.
CAUTION: Be sure that all mating hardware used to suspend the enclosure(s) is
specifically rated for overhead use and capable of supporting the weight load of the
enclosure(s) with an adequate Safety Factor. Some hardware fittings are NOT rated for
overhead use, but look very similar to those that are. Check with the manufacturer or
supplier to be sure.
If multiple enclosures are suspended one above the other, it is the installer’s responsibility
to insure that the combined weight load does not exceed the 100 lb Working Load Limit of
any one rigging fitting. This is particularly important if the enclosures are angled
downward, as most or all of the weight will be supported by the rear points only.
Community S-Series - Operation and Installation Manual - Page 48
Figure 15: STKIT Assembly of S-Series Enclosure with 4 Seat Track
Channels and M10 Hardware
(4) 8 x 1" FLATHEAD PHILLIPS
D RIVE DEEP THREAD SCREWS
(4) FLATHEAD ALLEN DRIVE SCREWS
(M10 x 40mm OR 3/8-16 x 1.5”)
(4) SEAT TRACK CHANNELS
IMPORTANT SAFETY WARNING: The STKIT is supplied with both 3/8-16 Unified Course
and 10mm Metric fasteners. These fasteners are very similar but they are NOT identical. It
is critically important that you use the M10 fasteners with all S- Series enclosures. DO NOT
USE THE 3/8-16 UNC fasteners under any circumstances. Use of fasteners with the
incorrect thread pitch could result in serious harm, injury or death, because the
threads will not hold securely under load.
2. Vertical Fly Kit: VFKIT
A Vertical Fly Kit, designated the VFKIT, is available to fit the trapezoidal full-range S1596, S-3294 and S-3594 loudspeakers.
The kit consists of two flat steel plates, slotted to align with the S-Series rigging fittings on
the tops and bottoms of the enclosures, and four eyebolts. It allows a pair of S-Series
enclosures to be flown in a horizontal splayed-array orientation.
Three, four, or more S-Series enclosures may be flown by purchasing additional Vertical Fly
Kits; two kits will fly three enclosures, three kits will fly four enclosures, and so on.
All parts in the kit are engineered to provide a high margin of safety when used with SSeries loudspeakers. The brackets are manufactured of steel and covered with a durable
powder-coat finish.
No hardware is provided to attach suspension cables to the Vertical Fly Kit. Such hardware
must be supplied by the installer, and should be rated for the weight load of the enclosures.
The installer is solely responsible for determining if all rigging components that are used to
suspend the enclosures are adequately sized and rated, and if the structure they are
suspended from is capable of safely supporting the aggregate weight load.
Community S-Series - Operation and Installation Manual - Page 49
VFKIT Parts List
(1)
(1)
(4)
(8)
(8)
(4)
(4)
Front Metal Bracket
Rear Metal Bracket
M10 30mm Bolts
M10 Flat Washers
M10 Split Lock Washer
M10 Eyebolts
M10 Hex Nuts
The installer must supply all other hardware for the installation.
VFKIT Assembly Instructions
1.
First, remove the two factory supplied flat-head Allen screws on the inside tops of
each enclosure (4 total).
2.
Assemble the components of the Vertical Fly Kit as shown in the drawing below. Attach
the Front Metal Bracket to the front of the enclosures using two M10 x 30mm bolts
fitted with lock washers and flat washers. At this time do not fully tighten the bolts.
3.
Next, attach the Rear Metal Bracket to the rear of the enclosure, again using two M10 x
30mm bolts fitted with lock washers and flat washers.
4.
Now, position the enclosures so that their rear corners are touching and lined up evenly
with each other. Tighten the bolts to a setting of 10 to 12 foot-lbs using a torque
wrench. Do not overtighten!
Figure 16: VFKIT Vertical Fly Kit Assembly
VFKIT Rigging Instructions
1.
The Vertical Fly Kit should be rigged from both the front and rear points using
appropriate load-rated hardware. After rigging, lift the loudspeakers about two feet off
the ground. Carefully inspect the rigging to make sure that no shackles are twisted
and that all fasteners are tightened properly.
Community S-Series - Operation and Installation Manual - Page 50
2.
The use of safety points in rigged or ‘flown’ systems is highly recommended. The
Vertical Fly Kit includes eyebolts intended for this purpose. The eyebolts should ideally
be attached to unused rigging fittings on the tops of the enclosures and connected to
safety cables. Safety cables are a second set of ‘backup’ cables that can sustain the
load in the event that the primary suspension system fails. Safety cables must always
be installed with little to no slack. A slack safety cable will result in a serious shock
load to the cable and the rigging hardware if the primary rigging fails. Such a shock
load could cause the safety cable or other rigging components to fail as well.
3.
After the primary rigging and the secondary safety cables have been attached, the
loudspeaker array is now ready to be raised to its proper trim height.
4.
Two threaded rigging fittings are provided on the rear of each enclosure. These fittings
are intended to be used as pull-back points, if a steep angle of downward inclination is
required. They are not intended to be used as the primary rigging points to suspend the
enclosures.
WARNING: Never reeve a primary support cable or a safety cable through a pair of
eyebolts or shackles (see drawing below). When a cable or sling is reeved through a pair of
eyebolts, it will load the eyebolts both laterally and vertically with a vector force that
greatly exceeds the actual weight of the loudspeaker array. The proper solution is to
provide separate cables for each one of the eyebolts.
Community S-Series - Operation and Installation Manual - Page 51
Figure 17: Never Reeve Cables!
Using More Than One VFKIT
More than one Vertical Fly Kit may be used to fly three, four, or more loudspeakers in an
array. Simply attach the additional kit(s) to the additional enclosures in the same manner
as the first kit.
WARNING: When assembling more than two enclosures into an array, it is very important
that the suspension cables be installed correctly so as not to place undue stress on either
the Vertical Fly Kit or on the enclosures themselves. The following rigging guidelines must
be observed explicitly:
Rigging Three Enclosures
When three enclosures are flown, both of the front and both of the rear hang points
must be used. In other words, two suspension cables or slings must attach to the front
hang points and two cables or slings must attach to the rear hang points, forming two lowangle bridles as shown in Figure 18 below. Note that every enclosure has at least two live
hang points attached to it.
Figure 18: Rigging Three Enclosures with the VFKIT
Community S-Series - Operation and Installation Manual - Page 52
It is also permissible to bridle from the front to rear hang points, using a separate bridle for
each enclosure. This may have to be done if the hang points in the building are oriented
left-to-right instead of upstage/downstage. However, setting the bridles for an
upstage/downstage hang, as shown above, provides the advantage of being able to adjust
the inclination of the array while it’s in the air. Setting the bridles for a left and right hang
introduces the issue of having to exactly match the length of the cables to avoid a lopsided
hang. Note that every enclosure has at least two live hang points attached to it.
WARNING: The angle of the bridles should be 30 degrees or less to stay within a
reasonable safety margin. Under no circumstances should the bridle angle ever
exceed 45 degrees, or failure to one or more rigging parts may occur. Lower
bridle angles put less stress on the rigging components and are always safer!
WARNING: Never reeve a Spanset, sling, wire rope or webbing through a shackle or hook
at the upper hang point. The legs of any bridle must always be separate parts, joined by a
shackle or a pairing ring. If a single part is reeved through a shackle or hook, there is
nothing to stop the load from becoming unbalanced and turning sideways in the air.
Moreover, the point on the sling where it contacts the metal shackle or hook will bear twice
as much load if it’s reeved, than if it’s a single part.
Rigging Four Enclosures
When four enclosures are flown, the two outermost front and two outermost rear
points must be used (four points total). The bridles may be run from the front to the rear
points, or they may be run from one outer rear point to the opposite outer rear point, and
the same for the outer front points. Bridling across the front points and the rear points,
which results in an upstage/downstage hang, provides the advantage of being able to
adjust the inclination of the array after it’s flown. Note that every enclosure has at least
two live hang points attached to it.
Figure 19: Rigging Four Enclosures with the VFKIT
Community S-Series - Operation and Installation Manual - Page 53
AVAILABLE ACCESSORIES
In addition to the rigging kits described above, these other useful accessories are available
for S-Series loudspeakers:
Padded Transport Covers
Protect your S-Series loudspeakers from scratches and mars.
Part # CVR-S12 (S-1296 loudspeaker cover)
Part # CVR-S15 (S-1596 loudspeaker cover)
Part # CVR-S32 (S-3294 loudspeaker cover)
Part # CVR-S35 (S-3594 loudspeaker cover)
Part # CVR-S215S (S-215S loudspeaker cover)
Part #CVR-S218S (S-218S loudspeaker cover)
SB5 Support Stand
Elevates a full-range loudspeaker using the subwoofer as
the base. Pole is 5’ x 1⅜” steel with a black finish. Part #
SB5.
Eyebolt Kit
Suspend your S-Series loudspeakers safely and easily.
Four eyebolts and four cup-washers included.
Part # M10EYBLTKIT.
Community S-Series - Operation and Installation Manual - Page 54
SERVICING S-SERIES LOUDSPEAKERS
Servicing a S-Series loudspeaker is straightforward and easy. All drivers are serviceable by removing the
screws that attach the protective grille to the front of the enclosure. The crossover is serviceable by
removing the input panel on the rear of the enclosure. There are no other user-serviceable parts.
TROUBLESHOOTING GUIDE
Should you have a problem with your S-Series loudspeaker(s), find the symptom and follow the associated
“What To Do” instructions below. Be aware that a particular symptom may have several possible causes.
SYMPTOM
PROBABLE CAUSE
WHAT TO DO
High distortion, low
output, or no output
from any or all
drivers.
Faulty connection to the
loudspeaker.
Using an ohmmeter, check the continuity of the wiring
to the loudspeaker. If the wiring is OK, remove the
input panel and check all solder joints on the
crossover and the wiring to the drivers. Visually
inspect solder joints as cold joints may only
malfunction under high current. Repair as needed.
Distortion from the
loudspeaker at higher
volume levels.
Too little amplifier
power.
If the power rating of the amplifier is too low, it will
clip at higher volume levels. Reduce the volume level
or use a more powerful amplifier.
Distortion from the
loudspeaker at
moderate to high
volume levels.
Driver is
malfunctioning.
Using a sine wave oscillator or wide range program at
moderate levels, listen to each driver to isolate the
problem. Replace as needed.
In BI-AMPLIFIED
mode bass is weak or
non-existent, and
highs sound
"muffled".
Wiring for LF and HF
sections is reversed
from electronic
crossover or amplifier.
Check wiring from crossover to amplifier, and
amplifier to loudspeaker. Make sure the HF amplifier
channel is connected to the HF driver and the LF
amplifier channel is connected to the LF driver.
Low or no output
from the lowfrequency driver.
Low-frequency driver,
crossover, or amplifier
is malfunctioning.
Test and replace as needed.
Low or no output
from the lowfrequency driver.
Mis-wired NL4compatible locking
connector.
Check wiring and correct as needed.
Low or no output
from the midfrequency driver
(applies to 3294 and
3594 only).
Mid-frequency driver,
crossover, or amplifier
is malfunctioning.
Test and replace as needed.
Low or no output
from the midfrequency driver.
Mis-wired NL4compatible locking
connector.
Check wiring and correct as needed.
Low or no output
from the highfrequency driver.
High-frequency driver,
crossover, or amplifier
is malfunctioning.
Test and replace as needed.
Low or no output
from the highfrequency driver.
Mis-wired NL4compatible locking
connector.
Check wiring and correct as needed.
Low volume level.
System gain is too low.
Check to make sure that the audio signal to the
amplifier is high enough to drive it properly. Check
all volume/level controls and gain switches in the
system including the amplifier input attenuator.
Possible solder joint
failure on crossover
card.
Community S-Series - Operation and Installation Manual - Page 55
SYMPTOM
PROBABLE CAUSE
WHAT TO DO
Low volume level.
Signal or speaker wire
connection is shorted.
Make sure the signal and input wire connections
inside all system connectors are not shorted or open.
Even one small wire strand shorting the +/– signal
terminals together anywhere in the system can cause
this problem.
Sound when
BI-AMPLIFIED is
“muffled”.
PASSIVE / BI-AMP
switch is in the wrong
position.
Switch on the input panel should be in the BI-AMP
MODE (RIGHT) position.
Mid and high
frequencies "muffled"
or missing in PASSIVE
mode.
PASSIVE / BI-AMP
switch is in the wrong
position.
Switch on the input panel should be in the PASSIVE
mode (LEFT) position.
No low frequencies in
PASSIVE mode.
PASSIVE / BI-AMP
switch is in the wrong
position or the wrong
connector pins are
being used.
Check that the switch is in the PASSIVE (LEFT)
position and that you are using connector pins #1
+/–.
No mid or high
frequencies in BIAMPLIFIED mode.
HF amplifier is not
functioning or
loudspeaker is
disconnected.
Check that the HF amplifier is turned on and that the
loudspeaker is properly connected to the amplifier.
No mid or high
frequencies in BIAMPLIFIED mode.
HF section of electronic
crossover is not
functioning or is
disconnected.
Check that any external electronic crossover has HF
output and that it is properly connected to the
amplifier.
No sound.
Amplifier is not on or
loudspeaker is
disconnected.
Check that amplifier is turned on and that
loudspeaker is properly connected to the amplifier.
No sound in PASSIVE
mode.
Wrong pins are wired
on the speaker
connector.
Make sure you are using connector pins #1 + / –.
No sound or very low
volume.
No audio signal.
Check that all the audio equipment in the signal chain
is powered on and that all gain controls are in the
proper position.
Noises from the
loudspeaker (buzzes
or rattles).
Grille or hardware is
loose.
Make sure the front grille screws are securely seated
and that any external mounting hardware is tightened
or secured from vibrating.
Noises from the
loudspeaker (buzzes
or rattles).
Driver is
malfunctioning.
Using a sine wave oscillator or wide range program at
moderate levels, listen to each driver to isolate the
problem. Replace as needed.
Poor sound quality in
BI-AMPLIFIED MODE.
Incorrect connections /
reversed polarity.
Check the connections to the LF and HF sections.
Verify that polarity is correct (+ and – amplifier
outputs go to + and – on all connectors and on the
loudspeaker).
Sound cuts in and
out.
The crossover
protection circuits have
been activated.
This usually means that the loudspeaker is being
constantly overdriven and the crossover protection
circuits are reducing the power to the loudspeaker as
a protective measure. Reduce the volume level to the
loudspeaker.
Sound cuts in and
out.
Bad connection.
Check all connections and cabling for shorts or loose
connections. Even one small wire strand shorting the
+/– signal terminals anywhere in the system can
cause this problem.
Sudden 3 dB loss in
sound.
The crossover
protection circuits have
been activated.
This usually means that the loudspeaker is being
constantly overdriven and the crossover protection
circuits are reducing the power to the loudspeaker as
a protective measure. Reduce the volume level to the
loudspeaker.
Community S-Series - Operation and Installation Manual - Page 56
REPLACEMENT PARTS
The following replacement parts may be ordered through authorized Community Service Stations. Please
contact Community for your nearest Service Station.
S-1296
S-1596
Part Number
Description
Part Number
Description
108920R
SPEAKER, 12"
108921R
SPEAKER, 15"
UC1
HF DRIVER UC-1
UC1
HF DRIVER UC-1
108190R
HORN, HF S-SERIES 12/15"
108190R
HORN, HF S-SERIES 12/15"
109003R
CROSSOVER S -1296
109004R
CROSSOVER S-1596
109532R
GRILLE, S--1296 W/HARDWARE
109533R
GRILLE, S-1596 W/HARDWARE
FOOTKIT
RUBBER FOOT KIT (4)
FOOTKIT
RUBBER FOOT KIT (4)
S-3294
S-3594
Part Number
Description
Part Number
Description
108920R
SPEAKER, 12"
108921R
SPEAKER, 15"
105654R
SPEAKER, 6.5", MID-FREQUENCY
105654R
SPEAKER, 6.5", MID-FREQUENCY
UC1
HF DRIVER UC-1
UC1
HF DRIVER UC-1
109071R
HORN, HF S-SERIES 32/35"
109071R
HORN, HF S-SERIES 32/35"
109002R
CROSSOVER S-3294/3594
109002R
CROSSOVER S-3294/3594
109534R
GRILLE, S-3294 W/HARDWARE
109535R
GRILLE,S-3594 W/HARDWARE
FOOTKIT
RUBBER FOOT KIT (4)
FOOTKIT
RUBBER FOOT KIT (4)
S-215S
S-218S
Part Number
Description
Part Number
Description
106475R
SPEAKER, 15-INCH SUB AIRFLOW
106105R
SPEAKER, 18-INCH AIRFLOW
108631R
CROSSOVER S-215S
109957R
CROSSOVER S-218S
109536R
GRILLE, S-215S W/HARDWARE
109537R
GRILLE, S-218S W/HARDWARE
FOOTKIT
RUBBER FOOT KIT (4)
FOOTKIT
RUBBER FOOT KIT (4)
105315R
KIT, STAND SOCKET 1-3/8
105315R
KIT, STAND SOCKET 1-3/8
SUMMING THINGS UP
S-Series loudspeakers and accessories are intelligently designed to provide you with
effective solutions for common and not-so-common sound reinforcement problems. These
great-looking and superb-sounding building blocks can be utilized in a wide variety of ways.
By giving careful consideration to your application needs, and taking the time to properly
position, focus, adjust, and equalize your system, S-Series products will provide years of
satisfying service. If questions or special needs arise at any time, the professional staff at
Community will be happy to offer experienced technical advice to assist you.
♫
Community S-Series - Operation and Installation Manual - Page 57
WARRANTY INFORMATION AND SERVICE
Transferable Warranty (Limited) – Valid in the USA Only
Community loudspeaker systems are warranted in the USA to be free from defects in materials and
workmanship for a period of five years, as determined by one of the following two methods, whichever is
longer:
1.
Starting from the date of retail purchase, as noted on the sales receipt from an authorized
Community dealer,
OR
2.
Starting from the date of manufacture, determined by the serial number, if the sales receipt is
not available.
This warranty applies to the product; therefore, the remainder of the warranty period will be automatically
transferred to any subsequent owner.
This warranty applies only to failure of a Community loudspeaker caused by defects in materials and
workmanship during the stated warranty period. It does not apply to a unit that has been subjected to
abuse, accident, modification, improper handling/installation, or repairs made without factory authorization
or by anyone other than authorized Community Field Service Stations. This warranty is void if the serial
number has been defaced, altered or removed.
Products covered by this warranty will be repaired or replaced at the option of Community, without charge
for materials or labor, provided all the terms of this warranty have been met.
Obtaining Warranty Service
Warranty service may be obtained from the factory, or from an authorized Field Service Station.
To obtain factory or field warranty service for products purchased in the United States, return the product
for inspection to the address below, freight prepaid, in the original packaging. If the original packaging is
not available, call or write Community Warranty Service to obtain proper packaging materials or hand carry
the product to the nearest Field Service Station.
Factory Service Center:
Community Warranty Service
333 East Fifth Street
Chester, PA 19013-4511 USA
Field Service Station:
Call (610) 876-3400 for the nearest Authorized Field Service Station
For factory service, please call (610) 876-3400 for a Return Authorization (R/A) number before shipping.
The following information must be included in the package:
1.
Owner’s complete name, daytime phone number, return street address and return authorization
number.
2.
The serial number of the product being returned and a copy of the retail sales receipt, if
possible.
3.
A complete description of the problem(s) experienced, including a brief description of how the
equipment is being used and with what brand, model and output power of amplifier.
Upon receipt, the service center will determine if the problem is covered under warranty. If covered under
this warranty, the product will be repaired or replaced, at Community’s option, and returned to the owner
freight prepaid. If the problem is not covered under this warranty, the owner will be notified of the problem
with an estimate of the repair costs.
Consequential and Incidental Damages: Community shall not be liable for any consequential or incidental
damages including, without limitation, injury to persons, property, or loss of use. Some states do not allow
Community S-Series - Operation and Installation Manual - Page 58
the exclusion or limitations of consequential or incidental damages, so the above limitations and exclusions
may not apply.
This Community warranty is not extended by the length of time which an owner is deprived of the use of the
product. Repairs and replacement parts provided under the terms of this warranty shall carry only the
remaining portion of the warranty.
Community reserves the right to change the design of any product from time to time, without notice and
with no obligation to make corresponding changes in products previously manufactured.
While this warranty gives specific legal rights, there may also be other rights that vary from state to state.
No action to enforce this warranty shall be permitted ninety days after expiration of the warranty period.
Warranty Information and Service For Countries Other Than The USA
To obtain specific warranty information and available service locations for countries other than the United
States of America, contact the authorized Community Distributor for your specific country or region.
Community S-Series - Operation and Installation Manual - Page 59
Community Professional Loudspeakers
333 East Fifth Street, Chester, PA 19013-4511 USA
Tel: 1-(610) 876-3400 | Fax: 1-(610) 874-0190
www.communitypro.com
© 2008 All Rights Reserved
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