Directed Audio 4500 Troubleshooting guide

100-05-0/F, LIB 2/6/01 9:26 AM Page 1
Troubleshooting Guide
Having trouble with the sound system?
Possible Cause
No sound (power LED not lit):
• power switch OFF
• batteries fully discharged (LED flashes briefly)
Charge indicator doesn’t light:
• blown fuse
No sound (power LED lights):
no output from source
input cable unplugged
input volume control low or off
plug inserted into switched speaker output,
but no speaker connected
Shortened battery life:
short in external speaker cable or speaker
total external speaker impedance < 4Ω
batteries not fully charged
batteries need replacement
Distorted sound:
• poor connection on input cable
• input signal too strong
Excessive hum or noise:
• input cable not shielded
• not using balanced microphone
Having trouble with the wireless system?
Possible Cause
No sound (TX ON indicator lights):
• mute switch set to ‘mute’ position
• wireless volume control low or off
• no mic plugged into belt-pack transmitter
No sound (TX ON indicator off):
• sound system not turned on
• transmitter power switch turned off
• low battery or no battery in transmitter
Owner’s Manual
ANCHOR Audio, Inc. (310) 784-2300
100-0005-000 / Revision F, 03/97
100-05-0/F, LIB 2/6/01 9:26 AM Page 3
Important Safeguards
CAUTION: To reduce the risk of electric shock, do not remove the cover.
No user-serviceable parts inside. Refer servicing to qualified personnel.
WARNING: To prevent fire or electric shock, do not expose this equipment to
rain or moisture.
ATTENTION: Pour eviter les risques de choc électrique, ne pas enlever le
couvercle. Aucun entretien de pièces intérieures par l'usager. Confier
l'entretien au personnel qualifié.
AVIS: Pour eviter les risques d'incendie ou d’électrocution, n'exposez pas cet
article à la pluie ou a l'humidité.
The lightning flash with arrowhead symbol, within an equilateral triangle, is
intended to alert the user to the presence of uninsulated “dangerous
voltage” within the product’s enclosure that may be of sufficient magnitude
to constitute a risk of electric shock to humans.
The exclamation point, within an equilateral triangle, is intended to alert the
user to the presence of important operating and maintenance (servicing)
instructions in the literature accompanying the appliance.
Le symbole éclair avec point de flèche à l'intérieur d'un triangle équilatéral
est utilisé pour alerter l'utilisateur de la presence à l'intérieur du coffret de
“voltage dangereux” non isolé d'ampleur suffisante pour constituer un risque
Le point d'exclamation à l'intérieur d'un triangle équilatéral est employé pour
alerter les utilisateurs de la présence d'instructions importantes pour la
fonctionnement et l'entretien (ser vice) dans le livret d'instruction
accompagnant l'appareil.
Rated power output:
70 watts @ 4Ω continuous
120 watts @ 4Ω dynamic
Max SPL @ rated power:
119 dB project mode, 109 dB music mode
Rated power output:
50 watts @ 4Ω continuous
Max SPL @ rated power:
117 dB project mode, 107 dB music mode
Batteries (two):
12 Volt rechargeable, 2.6 AH
(7.0 AH with heavy duty batteries)
Frequency response:
60 Hz - 15 kHz ± 3 dB music mode
(project mode: + 10 dB from 1.5 - 12kHz)
Speaker type:
8" woofer, titanium dome compression driver
Microphone inputs (two):
Lo-Z (1 kΩ), balanced, XLR
phantom powered, 12 VDC / 6.8 k
Auxiliary (line) input:
Hi-Z (10 kΩ), unbalanced, 1⁄4"-phone
Sensitivity for rated output:
-52 dBV (2.5 mVrms)
Auxiliary (line):
-14 dBV (200 mVrms)
Line output (post fader):
Lo-Z (< 1 kΩ), buffered, 1⁄4"-phone
Speaker out; switched:
8Ω, 1⁄4"-phone
Speaker out; unswitched:
4Ω, 1⁄4"-phone
DC Output:
12 Volts DC, 300 ma max.
AC power requirements:
Export model:
110-125 VAC, 50/60 Hz
208-240 VAC, 50/60 Hz
(MPA: 120 watts max, 30 watts idle.
MPB: 50 watts max)
Dimensions (HWD) :
22.5 x 13 x 10", 57 x 33 x 25 cm
31 pounds, 13 Kg.
36 pounds, 16 Kg.
44 pounds, 20 Kg.
Specifications subject to change without notice.
The date of manufacture of this Anchor Audio product can be determined by
the seven or eight digit serial number code. The fifth and sixth digits from the
right denote the year, the seventh digit (letter) from the right denotes the
month (A=Jan, B=Feb, etc.) Example: "XD960083" states that the unit was
manufactured in April of 1996. An "X" may or may not exist as the eighth
digit (letter) and has no significance in the serial number or date code.
100-05-0/F, LIB 2/6/01 9:26 AM Page 5
MIC-90 Handheld Microphone
Anchor’s dynamic, balanced, low impedance microphone
with a unidirectional pick-up pattern. It has an on/off switch
and comes with a 20' cable and mic clip.
SS-450 Speaker Stand
Thank you for choosing an Anchor Audio portable sound system. Our products
incorporate state-of-the-art design and the finest quality of materials and
workmanship. We’re proud of our products and appreciate the confidence which
you have shown by selecting an Anchor system.
I hope you’ll take a few of minutes to review this manual. We’ve incorporated
several unique features into our products, and your knowledge of how to use
them will enhance the performance and your enjoyment of the system.
Made of heavy duty structural aluminum.
MP-4501 Companion Speaker
David Jacobs, President on behalf of all Anchor employees
Dual function (music/project) unpowered speaker which can
be connected to the speaker outputs of a Liberty for increased
crowd coverage. Speaker cable not included.
Quick Use Guide
SC-50 Speaker Cable
Heavy duty 50' speaker cable.
Microphone floor stand with 33" adjustable boom.
Liberty is a portable sound system with a built-in amplifier
and multiple inputs. The dual-function feature makes it
suitable for music or speech applications, indoors or out.
You’ll need a microphone or some other input source before
you get started. If you have a battery-powered model, make
sure the batteries are fully charged before use (see page 11).
FL-4500 Admiral Lectern
Here’s how easy it is to use
VL-45 Storage Cover
Heady duty cover for Liberty.
MSB-201 Microphone Stand and Boom
Floor model lectern with a center console to accommodate a
Liberty sound system. It has a shock-mounted mic input.
Consult the
section on the
back page of
this manual.
1. Set the unit in front of your audience on the floor,
table or on a speaker stand.
2. Plug a microphone into the Mic 1 or Mic 2 input,
or plug an audio source into the auxiliary input.
3. Set all input level controls to minimum, and set the
bass and treble controls to the 12:00 position.
4. Turn the power switch ON (plug in the power cord if
you’re using an AC model). Slowly increase the level
control adjacent to the input used until desired volume
is reached.
5. For music and indoor applications, set the mode
switch to Music.
For speech and outdoor applications, set the mode
switch to Project.
6. Adjust the bass and treble for desired sound quality.
To operate the wireless mic system on wireless models, see
“Wireless Operation” on pages 12 and 13. And for more detailed
instructions, see the “Operation” section beginning on page 8.
100-05-0/F, LIB 2/6/01 9:26 AM Page 7
Save the
shipping carton
and packing
materials. They
were specially
designed to
ship your unit
Getting Started
Wireless Operation
Inspection and inventory of your system
Replacing the transmitter battery
Check unit carefully for damage which may have occurred
during transit. Each Anchor product is carefully inspected at
the factory and packed in a special carton for safe transport.
Note: The transmitter power switch must be in the OFF position!
• Liberty sound system
• Warranty registration card
HANDHELD: Unscrew the battery compartment cover on
the lower end of microphone. Install a fresh 9 Volt alkaline
battery* and replace the cover.
BODY-PACK: Press the “OPEN” end of the battery cover,
slide it back and lift the cover. Install a fresh 9 Volt alkaline
battery* being sure to observe proper polarity. Close the cover.
MN1604 or
All damage claims must be made with the freight carrier.
Notify the freight carrier immediately if you observe any
damage to the shipping carton or product. Repack the unit
in the carton and await inspection by the carrier’s claim agent.
Notify your dealer of the pending freight claim.
Operating the wireless microphone system
Returning your unit for service or repairs
Operating the wireless microphone system:
Should your unit require service, contact your dealer or our
Customer Service Department at (310) 784-2300 to obtain a
Return Authorization (RA) number. All shipments to Anchor
must include an RA number and must be shipped prepaid.
C.O.D. shipments will be refused and returned at your cost.
The audio signal from the built-in wireless receiver is fed into
the mixing bus. The wireless mic may be used simultaneously
with any of the other inputs .
1. Set the wireless volume control to minimum.
2. Turn the sound system power switch ON.
3. Slide the transmitter power switch to PWR.
The sound system’s TX ON indicator
lights to indicate wireless signal (RF)
is being transmitted and received.
4. Adjust the wireless control to desired volume.
Warranty registration
Please fill out the warranty card and return it with a copy of
your invoice to Anchor’s Customer Service Department. This
will activate your limited two year warranty.
Caution: Harmful feedback may occur when walking in front of a
sound system or speaker with a wireless microphone. Always point
mic away from speakers.
Using the microphone ON/MUTE switch:
When set to the “ON” position the mic operates normally.
To prevent unwanted sounds from being picked up without
turning the transmitter off, move switch to “MUTE” position.
(The handheld mic/transmitter comes with a protective
sleeve which fits over the power and mute switches to prevent
accidental movement during use. To install it, unscrew the
battery cover and slide the sleeve onto the microphone handle.
Replace the cover.)
100-05-0/F, LIB 2/6/01 9:26 AM Page 9
Now Featuring
Wireless Operation
Feedback Information
Setting up the wireless system
What causes feedback?
Checking the Frequency Code:
Feedback is a ringing, howling, or shrill sound that is selfgenerated by the sound system. It is the result of sound from
the speakers being picked up by the microphone(s) in use
and then re-amplified by the system. This can form a selfsustaining loop that can damage the sound system if allowed
to continue.
Before proceeding, you must first verify that the wireless
frequency of your transmitter matches the frequency of the
receiver installed in your Anchor sound system.
1. The control panel of the sound system should have
the following label:
Frequency Code label
(Shure designates a one- or two-letter code
which corresponds to the wireless frequency
at which the component operates.)
2. The frequency code must match the code found on
the transmitter as described below:
HANDHELD: Unscrew the battery compartment
cover on lower end of the microphone. Remove the
battery (if installed) and check code on the label.
label on handheld mic/transmitter
176.200 MHz
CANADA: 616 C9398
LX1 – CA 176.200 MHz
label on body-pack transmitter
BODY-PACK: Check the code on the label located
behind the belt clip.
3. If the frequency codes don’t match, locate the correct
transmitter whose code matches the sound system.
How to prevent feedback
CAUTION: Feedback can damage your equipment and may be
hazardous to your hearing. To avoid feedback, always make
sure volume controls are at minimum before turning unit on.
If feedback occurs, immediately reduce the volume.
About the transmitter battery gauge/indicator
Operating times
using a fresh
9 volt alkaline
battery *Duracell
MN1604 or
Assuming a battery is installed in the transmitter, you can
estimate the remaining operating time by sliding the power
switch to the PWR position (first turn the sound system off,
or set the transmitter mute switch to the MUTE position).
Observe the color of the LED indicator(s) that light up:
Battery LED Indicator
Operating Time
green & amber
6 - 20 hours
4 - 6 hours
2 - 4 hours
< 1 hour
100-05-0/F, LIB 2/6/01 9:26 AM Page 11
Keep in mind,
the best sound
system set-up is
when the
audience is not
conscious of a
sound system
being used.
Battery Operation (MPB-4500)
Setting up the Liberty sound system
Caring for the built-in batteries
Positioning of the speaker(s) is perhaps the most important
consideration when setting up a sound system. You should
survey the location prior to the activity and observe the
seating arrangement and area of coverage.
It is very important that you fully charge the batteries in your
system before first use, and as soon as possible after each and
every use—even if operated only briefly.
IMPORTANT: Do not store system with a partially or fully
discharged batteries, as this will reduce battery service life.
Basic principles of sound system set up:
• Position your sound system in front of the audience
and ahead of the microphone. This is especially
important when a person is addressing the audience.
Flashing = low battery.
Sound System
When the “Battery” LED flashes or won’t light:
The automatic protection circuit turns the unit off when the
batteries approach their ‘critical discharge point’ to prevent
damage. When the Battery LED begins flashing, this indicates
the batteries are low and the unit will shut off in 15 -30 minutes.
Charging the batteries
• Elevate the sound system so the sound projects over
the front listeners. This permits sound to reach the
listeners in the rear without overpowering those in
front. The Liberty is easily and safely elevated above
the audience by using Anchor’s SS-450 speaker stand.
• For long, narrow seating arrangements, position your
powered sound system in front and off to one side of
the listeners. Then position an unpowered companion
speaker mid-way back on the same side of the audience.
Direct the speakers diagonally across the audience.
Companion Speaker
Sound System
• There may be times when the crowd size requires
more than one Liberty sound system, or when the
overflow crowd is in a separate listening area. To use
multiple powered systems, connect a shielded cable
between the Line Out of the primary Liberty
Plug cord into AC outlet.
Light On = charging.
Flashing = fully charged.
To squeeze a
little more time
out of a fullycharged unit,
plug the AC
power cord into
an outlet while
you’re using
the system.
Your system has a built-in automatic charger designed to
properly charge and maintain the batteries—there is one thing
you need to do, however: Plug the power cord into an outlet!
But let’s go through it step by step, just to make sure.
1. Turn the system’s power switch off.
2. Plug the cord into an AC outlet (the Charger LED will
light, indicating the batteries are being charged).
When the batteries are fully charged (about 6-8 hours),
the Charger LED will flash. That’s all there is to it!
IMPORTANT: Always store your system with the batteries
in a fully charged condition. During extended periods of
storage, leave the system plugged into an outlet. If this is not
possible, charge the system at least once each month for a
minimum of 24 hours.
Expected service time from the batteries
Battery service time will vary depending on the volume level,
type of program usage and if a companion speaker is used
with the system. You can expect about 6-8 hours of operation
at medium volume, 2-4 hours at full volume of continuous
music input (usually longer for speech applications). Service
times are doubled on the MPB-4500H (heavy duty batteries).
100-05-0/F, LIB 2/6/01 9:26 AM Page 13
Mode (music/project) Switch
To control
feedback, try
attenuating the
respective tone
Use the mode switch to tailor the sound
output of the Liberty for your particular
system to the Auxiliary Input of the secondary system
(known as ‘daisy chain’ operation). Set the volume of
the second system, and thereafter the volume of the
primary Liberty will control both units. For even
more coverage, an unpowered companion speaker
can be driven by each powered Liberty system.
Using the music mode:
Liberty provides flat, full-range frequency response for
music/singing or indoor vocal applications.
Companion Speaker
Using the project mode:
Frequencies in the vocal range (800Hz-12KHz) are boosted
for added clarity and efficient projection. Use for outdoor
functions, large crowds and speech applications.
When using the MP-4501 speaker with a powered Liberty, verify
that the mode switch of both units are set the same.
12 Volt DC Output
(300 milliamp)
The DC output jack is used to power
auxiliary equipment such as an outboard
wireless receiver or Anchor’s Mini-Mix. It
is rated output is 12 volts DC, 300 ma
maximum (output available at jack may be
lower depending on options installed).
Powered Liberty “Daisy Chained” to
the performers Liberty Sound System.
+12 VDC
Setting up difficult rooms
Reverberant rooms—those with acoustically-reflective
surfaces like glass or concrete (such as a gymnasium), can be
troublesome when using a sound system. Proper care must
be used during setup to minimize feedback, which is caused
by the microphone ‘hearing’ the sound reflected back from
the walls, floors and ceilings.
Using the cassette tape player
The cassette player features auto reverse for continuous
playback. The audio signal is fed directly into the mixing bus
so the sound can be mixed with other inputs of the Liberty.
To change tracks
(sides), push
button half-way in.
To eject tape, push
button fully in.
Techniques to reduce feedback in difficult rooms:
Note: Use only high-quality tapes, and periodically clean the tape
head with a cleaning kit.
A lapel mic will
perform poorly
under these
conditions and
should not be
• The best microphones to use in feedback-prone rooms
are handheld, CollarMic™ or headset boom types. They
allow the mic element to be close to the mouth so the
system ‘sees’ more of the users voice and less of the
room. The gain control can be turned down while still
maintaining adequate volume—another important
factor in reducing feedback.
• Orienting the speakers directly at the crowd and away
from the walls (and the user, or course) will help
reduce feedback. Experimentation may be necessary.
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Mic 1 and Mic 2 Inputs
Liberty Control Panel
Mic Volume
Liberty is equipped with two balanced, low impedance XLR
microphone inputs. Use with a balanced microphone to help
prevent hum or interference when using long cables. They
have phantom power for use with condenser-type microphones.
Auxiliary Input
(1/4" phone jack)
Auxiliary Input
Mode Switch
Mic Inputs (XLR)
(battery models only)
The auxiliary (line-level) input is used for playback of a tape
or CD player, musical instrument, VCR or similar source. It
may be combined with the mic inputs for a composite output.
Note: All line-level connections must be made with shielded
cable to avoid hum, buzzing or radio interference.
DC Output
Line Output
Line Output
(1/4" phone jack)
(line level)
Charger Indicator
(line level)
Plug cord into AC outlet.
Light On = charging.
Flashing = fully charged.
(300 milliamp)
AC Receptacle
Flashing = low battery.
115 VAC, 50/60 Hz
External Speaker Outputs
Use the speaker outputs to drive an unpowered speaker for
greater crowd coverage. There are two output jacks located
in the lower right corner of the back panel:
(100 watts)
250 V/2A
Power Switch
Speaker Output
Using the unswitched speaker output.
Speaker Output
Use the unswitched output to power a companion speaker in
addition to the speakers in the Liberty (for broader sound
coverage and distribution). Use a speaker rated at 8Ω, such as
Anchor’s MP-4501.
Using the switched speaker output.
Operating the sound system
1. Set all input level controls to minimum and bass and
treble to 12:00 position before turning the power on.
2. Plug a microphone into either Mic input jack or
connect an audio source to the auxiliary input.
3. Turn power ON (red LED above switch will light).
On battery models, if the LED flashes or does not light,
the batteries must be charged (see page 11).
4. Adjust the level control adjacent to the input used to
desired volume level.
5. Adjust the bass and treble controls for desired sound.
The output signal is a composite of all the inputs. Use it to
record your presentation, or to “daisy chain” another powered
sound system to the Liberty for greater crowd coverage.
When a plug is inserted into the switched speaker output, the
Liberty’s internal speakers are disconnected and all amplifier
power is routed to the auxiliary speaker only.
Two unpowered companion speakers can be “chained”
to the switched speaker output.
NOTE: When using an auxiliary speaker with battery models,
additional power is required to drive the companion speaker which
will shorten battery service time.