AV Products
User Manual: Centre Channel Speakers: C1 • C3 • C4 • C5 • C6 • C7
Sub-woofers: C1 • C2 • C4 • C6 • C7
M U LT I C H A N N E L
®
AC O U S T I C ENGINEERS
Safety Warnings
AV Products
1. Read instructions – all the safety and operating instructions should be read
before the appliance is operated.
2. Retain these instructions – the safety and operating instructions should be
retained for future reference.
3. Heed warnings – all warnings on the appliance and in the operating
instructions should be adhered to.
4. Follow instructions – all operating and other instructions should be
followed.
5. Water and moisture – the appliance should not be used near water, for
example near a bathtub, washbowl, kitchen sink, laundry tub, in a wet
basement or near a swimming pool etc..
6. Ventilation – the appliance should be situated so that its location or
position does not interfere with its proper ventilation. For example, the
appliance should not be situated on a bed, sofa, rug or similar surface that
may block the ventilation openings. Similarly, the appliance should not be
built into an installation, such as a bookcase or cabinet, that may impede
the flow of air through the ventilation openings.
7. Heat – the appliance should be situated away from heat sources such as
radiators, stoves or other appliances that produce heat.
8. Power sources – the appliance should be connected to a power supply only
of the type described in the operating instructions or as marked on the
appliance.
9. Power cord protection – power supply cords should be routed so that they
are not likely to be walked on or pinched by items placed upon or against
them, paying particular attention to cords at plugs, convenience
receptacles and the point where they exit the appliance.
10. Cleaning – the appliance should be cleaned only as recommended by the
manufacturer.
11. Unattended periods – the power cord of the appliance should be
unplugged from the outlet when left unused for a long period of time.
12. Object and liquid entry – care should be taken so that objects and liquids
do not fall into the appliance.
13. Damage requiring service – the appliance should be serviced by qualified
service personnel when:
i. the power supply cord or the plug has been damaged
ii. objects have fallen or liquid has been spilled into the appliance
iii. the appliance has been exposed to rain or other serious liquid exposure
iv. the appliance does not appear to operate normally or exhibits a marked
change in performance
v. the appliance has been dropped or the cabinet damaged
14. Servicing – the user should not attempt to service the appliance beyond
those measures described in the operating instructions.All other servicing
should be referred to qualified service personnel.
15. Grounding or polarisation – precautions should be taken so that grounding
or polarisation means for the appliance are not defeated.
1
AV Products
Introduction
Welcome. In selecting ATC you have chosen an
ATC has become synonymous with active systems. Choosing to offer active
example of the finest audio engineering
loudspeakers (where the passive crossover network is replaced by active filters and
available. ATC was founded on a principle of
multiple power amplifiers) is simply a result of the uncompromising attitude to
engineering excellence, and that principle still
loudspeaker design.While passive systems still have their place, and ATC engineering
defines our products today. Given the right
skills can still bring remarkable results from them,“active” is a fundamentally better
opportunities, ATC products will deliver
solution to the problems posed by accurate, high level music reproduction.The ATC
exceptional audio performance, but the
instinct is always for the better solution. Not cheaper, not quicker, but better.
opportunities will only arise from careful and
It was the development of active loudspeakers that first brought ATC into
thoughtful installation and use. Please read the
electronics design and engineering. Active speakers demand multiple power
following manual fully. It will help you
amplifiers so ATC from the mid 1980s became not just a loudspeaker manufacturing
understand the product and to realise its full
company but an electronics manufacturer too.The further step from electronics for
potential. We are happy to answer questions
and offer advice on any issues that arise
through installation or use of ATC products.
Contact details can be found at the back of this
active speakers to a range of stand-alone amplifier products was natural and now
means that ATC engineering is
available from the recording
Contents
desk or CD player output to
Page 2
the ears.
manual.
C4/C5/C6/C7 Active Centres
Section 1.1
Centre Speaker
Placement
Section 1.2
Connection
Page 4
Section 1.3
Section 1.4
Section 1.5
Signal Cable Options
Operation
Listening
Page 5
Section 1.6
Section 1.7
Care and Maintenance
Warranty and Contact
Specifications
Page 6
C1/C3 Passive Centres
Section 2.1
Centre Speaker
Placement
Section 2.2
Amplification
Section 2.3
Connection
Section 2.4
Listening
Page 7
Section 2.5
Section 2.6
Page 8
C1 Active Sub-woofer
Section 3.1
Sub-woofer Placement
Section 3.2
Connection
Page 9
Section 3.3
Section 3.4
Operation
Listening
Page 10
Section 3.5
Section 3.6
Care and Maintenance
Warranty and Contact
Specifications
Page 11
C2, C4, C6, C7 Active Sub-woofers
Section 4.1
Sub-woofer Placement
Section 4.2
Connection
Section 4.3
Signal Cable Options
Page 12
Section 4.4
Section 4.4
Operation
Listening
Page 13
Section 4.6
Section 4.7
Care and Maintenance
Warranty and Contact
Specifications
Page 14
System Installation Notes
Section 5.1
Full Bandwidth Speaker
Positioning
Page 15
Section 5.2
From modest beginnings ATC
ATC was founded in London in 1974 by Australian
emigre Bill Woodman, who still heads the company
today. An enthusiastic pianist and engineer he was
naturally drawn to loudspeaker design and after a
period working at Goodmans, where many of the
names that went on to found British loudspeaker
companies began their careers, he struck out on
his own. The premise on which ATC began is a
simple one, and one that in many respects is still
true today: hi-fi loudspeakers tend to be detailed
and accurate but of limited dynamic range, while
professional monitor speakers tend to express the
has grown to become one of
the very few manufacturers
successful
across
both
domestic and professional
audio. By selecting ATC you
Introduction
Page 3
join a group of music lovers,
professional audio engineers,
studios and musicians across
the World that understand and
value the engineering that
goes into an ATC product and the sound that comes out.
opposite character. ATC products were designed
from the outset to offer the best of both. It’s an
easy concept to describe, but surprisingly difficult
to engineer.
The
difficulty
inherent
in
designing
such
loudspeakers is one of scale. Hi-fi levels of accuracy
and detail call for lightweight moving parts and
delicate engineering. Professional monitor levels of
performance however demand far more robust
components engineered to survive the rigours of
high level use for extended periods. The only way
to combine the two is through precision
engineering of a class and scale more often
associated with aerospace or motorsport. But the
results are worth the effort and the cost. ATC
loudspeakers, with their unique in-house designed
drivers, combine the best of hi-fi and professional
to devastating effect.
Section 5.3
Section 5.4
2
Care and Maintenance
Warranty and Contact
Specifications
Bass Management in
Domestic Systems
Bass Management
Compromises
Bass Management
Conclusions
Centre Speaker Installation
C4/C5/C6/C7 Active
1.1 Centre Speaker Placement
The positioning constraints on a centre channel loudspeaker are always influenced by
the type and location and of the associated screen. However, the basic parameters that
influence the subjective performance of any loudspeaker in a listening room alignment to the listening position and proximity of room boundaries - also apply to
a centre channel and should be taken into account.
ATC centre channel speakers are intended to be positioned relatively clear of room
boundaries and centrally either just below or just above the screen. If the screen is
either a plasma or projector type located close to the wall it may not be possible to
position the centre channel speaker very far forward. In these cases, some adjustment
of low frequency equalisation via the AV processor may be necessary to reduce excess
bass. It is always preferable however to experiment with loudspeaker positioning
before resorting to electronic equalisation.
If the screen is a CRT type and its stand is also to carry the centre channel speaker it
is advisable to mount the speaker via some decoupling material so that vibration does
not disturb the picture.
While every ATC centre channel speaker is effectively magnetically shielded, the
extreme sensitivity of some CRT tubes to residual levels of magnetic flux may mean
that, in rare cases, ATC centre channel speakers are not appropriate. Adjusting the
relative front/back position of the center speaker and the CRT can reduce magnetic
interference but should your screen suffer intractable picture distortion caused by the
proximity of a centre speaker contact your dealer or installer for advice.
If the centre speaker is to be placed in any form of cabinet, adequate side and top
clearance for cooling airflow must be provided.
More information on loudspeaker positioning in multi-channel systems can be found
later in this manual in Section 5.
Diagram 1 - input connection pins
1.2 Connection
Two cable connections are required for each monitor: one for
mains power and one for the audio signal. The mains cable is
specifically supplied to comply with local statutory safety
approvals and alternatives should not be substituted. If you intend
to use your monitors in an alternative territory please contact
Pin 2, Signal (hot)
Pin 1, Screen
Pin 3, Signal (return)
ATC for advice.The mains connection must always be earthed.
The signal cable and plug (not necessarily supplied) should be
of a good quality and XLR terminated. Poor cable and plug
quality will compromise the performance of your monitors.The
signal input pin configuration is illustrated in Diagram 1.
3
C4/C5/C6/C7 Active
Centre Speakers
Installation
1.3 Signal Cable Options
1.4 Operation
Balanced cable configuration is the preferred
The C4, C5, C6 and C7 are connected to the mains and signal cables via sockets on
option, however unbalanced connection is possible.
the rear panel. The rear panel also carries the mains switch and fuse holder. Each
Diagrams 2 and 3 illustrate the signal cable
feature is described below.
connections required for each option. Balanced
•
(XLR to XLR) connection offers lower noise and
Mains Inlet: The supplied mains power lead (appropriate to the local territory)
should be connected here. Ensure that the mains voltage specified on the panel
better immunity to “hum” pick-up. Unbalanced
(above the input socket) corresponds with the local supply.
(XLR to Phono or Two Pole Jack) connection
•
carries risk of hum caused by multiple signal earths.
Hum
problems
resulting
from
Power Switch: Switches on the speaker.When switched on the indicator on the
back of the monitor will illuminate (C6 & C7 only).
unbalanced
•
connection may be reduced by making ONE of the
Fuseholder: Should a speaker fail to switch on when the power switch is
following modifications to the signal cable
operated the fuse should be inspected. Lift out the fuseholder cover using a
connections: If the driving preamplifier (or desk) is
small flat-blade screwdriver, remove the fuse and inspect it for damage. If
“double insulated” (i.e. has no mains earth),
required, a spare fuse may be supplied in the body of the fuseholder cover. It
disconnect the signal cable screen at the RCA Phono
should be stressed however that fuses most often fail only because of a serious
plug end. Alternatively, disconnect the signal cable
electrical fault. If this is the case then simply replacing the fuse will only result in
screen at the XLR end.This second option will make
another fuse failure. The monitor should be returned to ATC for service if a
the source the reference signal earth.
second fuse fails.
•
Input Socket: The audio signal cable should be connected here. Balanced or
unbalanced cables may be used (See Section 1.3).
Due to the nature of the electronics in ATC active loudspeakers it
is quite normal for a sound to be heard from the speaker when the
Diagram 2 - balanced cable
power is applied or disconnected.The noise heard will not damage
the speaker and is quite normal. Although ATC uses the highest-
3 Pin Male XLR
Connector
Two Core Screened Cable
2
3
1
3 Pin Female XLR
Connector
Hot
Return
2
Screen
1
grade components, a different noise may be heard from each
speaker due to slight tolarance variations in the amplifier
components.
3
1.5 Listening
To Monitor Input
To Source Output
The ear and brain tend to interpret distorted sound as loudness
and thus underestimate the actual level of undistorted sound. The
Diagram 3 - unbalanced cable
C4, C5, C6 and C7, like all ATC monitors, demonstrate very much
lower levels of distortion than conventional systems of a similar
3 Pin Male XLR
Connector
Phono (RCA)
Connector
Two Core Screened Cable
size and it is therefore advisable to begin listening at an artificially
low level and carefully increase the volume. It is also possible for
2
Hot
Return
the C4, C5, C6 or C7 to produce sufficient sound pressure levels
1
Screen
make the sound appear harsh.Any audible distortion indicates that
3
for your ears themselves to become a source of distortion and
either the system or your ears are being overloaded and that the
To Monitor Input
4
To Source Output
volume level should be reduced.
C4/C5/C6/C7 Active
Specifications
C4 Active Centre
C5 Active Centre
C6 Active Centre
C7 Active Centre
25mm (1")
25mm (1")
25mm (1")
75mm (3")
2 x 234mm (9")
50Hz – 12kHz
Drivers:
HF
MF
LF
2 x 125mm (5”)
2 x 150mm (6”)
25mm (1")
75mm (3")
2 x 234mm (9")
Amplitude Linearity ±2dB
75Hz – 20kHz
75Hz – 12kHz
50Hz – 12kHz
Cut-off Frequencies
(-6dB free standing)
57Hz & 20kHz
48Hz & 20kHz
32Hz & 20kHz
32Hz & 20kHz
Matched Response
±0.5dB
±0.5dB
±0.5dB
±0.5dB
±10° Coherent
±80° Coherent
±10° Coherent
±80° Coherent
±60° Coherent
±10° Coherent
±60° Coherent
±10° Coherent
Max Continuous SPL
108dB SPL @ 1 metre
112dB SPL @ 1 metre
115dB SPL @ 1 metre
115dB SPL @ 1 metre
Crossover Frequency
2.5kHz
2.5kHz
380Hz and 3.5kHz
380Hz and 3.5kHz
Input Connector
Male XLR
Male XLR
Male XLR
Male XLR
Input Sensitivity
1.0V Balanced
1.0V Balanced
1.0V Balanced
1.0V Balanced
Input Impedance
>10k Ohms
>10k Ohms
>10k Ohms
>10k Ohms
200 Watts RMS
200 Watts RMS
50 Watts RMS
50 Watts RMS
200 Watts RMS
100 Watts RMS
50 Watts RMS
200 Watts RMS
100 Watts RMS
50 Watts RMS
Dispersion:
Horizontal
Vertical
Amplifier Output:
LF
MF
HF
Overload Protection
All products: Active Momentary Gain Reduction on all amplifiers plus Tweeter LDR protection.
Cabinet Dimensions (HxWxD) 190 x 550 x 380mm
245 x 650 x 571mm
388 x 1200 x 511
550 x 1200 x 480mm
Overall Weight
48.9kg (107.5lb)
45kg (99lbs)
83.6kg (184.3lb)
101kg (222.7lb)
Power Requirements:
Voltage
Frequency
100, 115, 230V
50/60Hz
100, 115, 230V
50/60Hz
100, 115, 230V
50/60Hz
100, 115, 230V
50/60Hz
Cabinet Finishes
Black/Silver
Black/Silver
Cherry,Walnut, Rosewood
veneers standard. Others to
special order.
Black/Silver
Others to special order
Specifications comply with the following standards: Australian Standard Specification No 1127 "Sound System Loudspeakers" Part 5,
IEFE Specification Standard No 219-1975
ATC reserves the right to vary products and specifications without prior notice. Acoustic Transducer Co. is a trading name and ATC
is the registered trade mark of Loudspeaker Technology Ltd.
1 . 7 Wa r r a n t y a n d C o n t a c t
1.6 Care and Maintenance
All ATC products are guaranteed against any defect
High technology material finishes are used in these products. The surfaces are
in materials or workmanship for a period of two
durable and with a little care can be kept as good as new even under conditions of
years from the date of purchase.Within this period
heavy use. Normally a dry duster will be all that is required to keep the finishes
we will supply replacement parts free of charge
clean. Heavy soiling can be cleaned using a cloth slightly moistened with a non-
provided that the failure was not caused by misuse,
abrasive household cleaner.
accident or negligence.
There are no components within the speakers that can be considered expendable,
Purchasers who complete and return the
or that would benefit from regular maintenance. There is no requirement for any
Warranty Card will have their warranty period
kind of routine service work and there is no schedule for preventative maintenance.
Should a speaker fail to switch on when the power switch is operated the fuse
should be inspected. Lift out the fuseholder cover using a small flat-blade
screwdriver, remove the fuse and inspect it for damage. If required, a spare fuse may
extended up to a period of six years from the
date of purchase.This guarantee does not limit
statutory rights.
be supplied in the body of the fuseholder cover. Fuses most often fail only because
ATC can be contacted at:
of a serious electrical fault. If this is the case then simply replacing the fuse will only
Loudspeaker Technology Ltd, Gypsy Lane, Aston
result in another fuse failure.The speaker should be returned to ATC for service if
Down, Stroud, Gloucestershire GL6 8HR, UK.
a second fuse fails.
Telephone:
01285 760561
There are no user replaceable parts within the speakers and in the unfortunate
Fax:
01285 760683
event of any malfunction, repair should be referred to either the supplying dealer or
Email:
info@atc.gb.net
consultant, the relevant importer, or ATC.
Website:
www.atc.gb.net
5
C1/C3 Passive
Centre Speaker
Installation
2 . 1 C e n t re S p e a ke r
Placement
2.2 Amplification
The choice of partnering amplifier for the C1 and C3 will have significant influence on
The positioning constraints on a centre channel
loudspeaker are always influenced by the type and
location and of the associated screen. However, the
basic parameters that influence the subjective
performance of any loudspeaker in a listening room
- alignment to the listening position and proximity of
room boundaries - also apply to a centre channel
and should be taken into account.
The C1 and C3 are intended to be positioned
relatively clear of room boundaries and centrally
either just below or just above the screen. If the
screen is either a plasma or projector type located
close to the wall it may not be possible to position
the C1 or C3 very far forward. In these cases, some
adjustment of low frequency equalisation via the AV
the performance of the system. Consider the following when selecting the amplifier:
• With any passive loudspeaker there is a trade-off between low frequency
extension and sensitivity. The C1 and C3’s extended low frequency response
means that their sensitivity is relatively low. It is advisable therefore to select an
amplifier of relatively high power capabilities. Use of an under specified amplifier
will result in distortion at high levels and may risk damage. Valve or solid state
amplifiers with high output impedance should be auditioned carefully to establish
that their characteristic reduced damping at low frequencies is acceptable.
• Thanks in part to their underhung voice coil construction, the C1 and C3 not only
demonstrate extremely low distortion at all levels but also a greatly enhanced
effective dynamic range. This exceptional distortion performance, also combined
with very wide dispersion, will ruthlessly reveal deficiencies in ancillary equipment.
It is advisable therefore to audition the C1 or C3 with your proposed amplifier
and ancillary system.
processor may be necessary to reduce excess bass.
It is always preferable however to experiment with
2.3 Connection
loudspeaker positioning before resorting to
electronic equalisation.
The C1 and C3 are equipped with a “bi-wire” connection panel that enables
separate amplification of the bass drivers and tweeter. Remove the linking bars
If the screen is a CRT type and its stand is also to
between the two pairs of terminals if you wish to take advantage of the bi-wire
carry the C1 or C3 it is advisable to mount the
facility.
speaker via some decoupling material so that
vibration does not disturb the picture.
The terminals can accommodate either stripped cable ends or 4mm plugs. Always
While every ATC centre channel speaker is
conductor (79 strand). Cable of a smaller cross sectional area or fewer strands is
effectively magnetically shielded, the extreme
unsuitable. For cable runs longer than 10m use a significantly heavier gauge cable.
sensitivity of some CRT tubes to residual levels of
Consult your dealer or consultant for specific cable recommendations.
use good quality speaker cable with a 2.5mm2 minimum cross sectional area per
magnetic flux may mean that, in rare cases, ATC
centre channel speakers are not appropriate.
Ensure that the positive and negative terminals on each connection panel are
Adjusting the relative front/back position of the
connected back to the corresponding positive and negative terminals on the amplifier.
center speaker and the CRT can reduce magnetic
interference but should your screen suffer
2.4 Listening
intractable picture distortion caused by the
proximity of a centre speaker contact your dealer
The ear and brain tend to interpret distorted sound as loudness and thus
or installer for advice.
underestimate the actual level of undistorted sound. The C1 and C3, like all ATC
monitors, demonstrates very much lower levels of distortion than conventional
More information on loudspeaker positioning in
multi-channel systems can be found later in this
manual in Section 5.
systems of a similar size and it is therefore advisable to begin listening at an
artificially low level and carefully increase the volume. It is also possible for the C1
and C3 to produce sufficient sound pressure levels for your ears themselves to
become a source of distortion and make the sound appear harsh. Any audible
distortion indicates that either the system or your ears are being overloaded and
that the volume level should be reduced.
6
C1/C3 Passive
Specification
C1 Passive Centre
C3 Passive Centre
HF
LF
25mm (1")
2 x 125mm (5")
25mm (1")
2 x 150mm (6")
Amplitude Linearity ±2dB
75Hz – 12kHz
60Hz – 12kHz
Cut-off Frequencies
(-6dB free standing)
57Hz & 20kHz
48Hz & 20kHz
Matched Response
±0.5dB
±0.5dB
±10° Coherent
±80° Coherent
±10° Coherent
±80° Coherent
Drivers:
Dispersion:
Horizontal
Vertical
Max Continuous SPL
108dB SPL @ 1 metre
112dB SPL @ 1 metre
Crossover Frequency
2.5kHz
2.5kHz
Input Connector
Binding Posts/4mm Sockets (Bi-Wire capable)
Sensitivity
84dB for 1 Watt @ 1 metre
86dB for 1 Watt @ 1 metre
Nominal Impedance
8 Ohms
8 Ohms
Recommended Power
Amplifier:
100 - 1500 Watts
50 - 1500 Watts
Cabinet Dimensions (HxWxD) 160 x 450 x 268mm
212 x 600 x 300mm
Overall Weight
11kg (24.2lb)
30kg (66.0lb)
Cabinet Finishes
Cherry, Rosewood veneers standard.
Other veneers can be supplied to special order.
Specifications comply with the following standards: Australian Standard Specification No 1127 "Sound System Loudspeakers" Part 5, IEFE Specification Standard
No 219-1975
ATC reserves the right to vary products and specifications without prior notice. Acoustic Transducer Co. is a trading name and ATC is the registered trade mark
of Loudspeaker Technology Ltd.
2.5 Care and Maintenance
High technology material finishes are used in this product.The surfaces are durable
and with a little care can be kept as good as new even under conditions of heavy
use. Normally a dry duster will be all that is required to keep the finishes clean.
2 . 6 Wa r r a n t y a n d C o n t a c t
Heavy soiling can be cleaned using a cloth slightly moistened with a non-abrasive
All ATC products are guaranteed against any
household cleaner.
defect in materials or workmanship for a period of
There are no components within the speaker that can be considered expendable,
two years from the date of purchase. Within this
or that would benefit from regular maintenance. There is no requirement for any
period we will supply replacement parts free of
kind of routine service work and there is no schedule for preventative maintenance.
charge provided that the failure was not caused by
misuse, accident or negligence.
There are no user replaceable parts within the speaker and in the unfortunate event
of any malfunction, repair should be referred to either the supplying dealer or
Purchasers who complete and return the
consultant, the relevant importer, or ATC. ATC has every confidence in the quality
Warranty Card will have their warranty period
of each product that it manufactures.
extended up to a period of six years from the
date of purchase.This guarantee does not limit
statutory rights.
ATC can be contacted at:
Loudspeaker Technology Ltd, Gypsy Lane, Aston
Down, Stroud, Gloucestershire GL6 8HR, UK.
Telephone:
01285 760561
Fax:
01285 760683
Email:
info@atc.gb.net
Website:
www.atc.gb.net
7
C1 Active
Sub-woofer
Installation
3.1 Sub-woofer Placement
3.2 Connection
The subjective performance of any sub-woofer will
Mains power and signal connections are required for the C1 Sub-woofer. The mains
be fundamentally influenced by the acoustic
cable is specifically supplied to comply with local statutory safety approvals and
character of the room in which it is used, and its
alternatives should not be substituted. If you intend to use your sub-woofer in an
position within the room. Speaker and sub-woofer
alternative territory please contact ATC for advice.The mains connection must always
systems are most often installed in rooms which
be earthed. Ensure that the local mains voltage matches that specified on the
are comfortable to sit and talk in, and the typical
connection panel voltage selector.
mixture of carpets, curtains and soft furnishings
help ensure that middle and high frequencies are
reasonably well controlled.There may however be
low frequency problems; either too much or too
little bass.
The audio signal can be connected to the C1 either through the stereo pair of linelevel RCA Phono inputs, or through a stereo set of 4mm binding post connectors.The
binding post connectors are designed to accept high level signals from power
amplifiers but should be used only if an appropriate line level signal is not available.
High level signals from power amplifiers rated at up to 300 Watts into 8 Ohms are
To minimise these problems the sub-woofer
compatible. Take care to ensure that correct, positive to positive and negative to
should be kept away from corners or walls. Start
negative, polarity of high-level connections is retained. Diagram 1 illustrates these
with it positioned around 1 metre from the side
signal connection options.
walls and 2 metres from the back. If the balance is
bass-light, the sub-woofer can be moved towards
the corner. Use the sub-woofer controls (see
Section 4.5) to optimise satellite integration and
If two signal connections are made to the sub-woofer (i.e. a stereo pair) the left and
right signals will be summed to mono internally by the amplifier. The mono subwoofer signal from an audio-visual processor may be connected to either left or right
line-level Phono input.
for fine tuning rather than to compensate for
inappropriate positioning All rooms vary and it is
The signal cable(s) and plug(s) should be of a good quality. Poor cable and plug quality
a good idea to experiment with both listening and
will compromise the performance of your sub-woofer.
speaker positions until a good compromise is
reached.
If the sub-woofer is to be placed in any form of
enclosure, adequate side and top clearance for
Diagram 1 - C1 signal connections
cooling airflow must be provided. For professional
installations the requirements are often very
specific. Please consult with an experienced
professional acoustician if necessary.
More information on sub-woofer installation and
use can be found later in Section 5.
Stereo high level
inputs. Connect to
satellite power
amplifier output if
line-level signal is
not available.
Stereo line-level
inputs. Connect to
line-level signal from
satellite preamplifier
or AV processor.
8
C1 Active
Sub-woofer Installation
3.3 Operation
The C1 sub-woofer control and connection panel provides a range of adjustment
facilities to assist its integration with the satellite speakers. These facilities are
explained below and illustrated in Diagrams 2, 3 and 4.
Level: Sets the overall sensitivity of the sub-woofer.
Diagram 2 - connection and control panel
Initially the level control should be set towards the
centre of its range and only adjusted once the
Filter Frequency and Mode controls have been set.
Filter Frequency: Varies the upper crossover
frequency as indicated on the control panel and
Diagram 3. Filter frequency is the fundamental
parameter that defines the integration of the subwoofer with the satellites. The Filter Frequency
control should be set at or slightly above the
specified low frequency cut-off of the satellite
speakers.
If the Filter Frequency control is set fully anticlockwise, a supplementary control providing
alternative fine adjustment of filter frequency
between 40 and 100Hz becomes operational.
Mode: With the Mode control set to the Music+ position the sub-woofer passband frequency response is fundamentally flat and in phase with the satellite
speakers.With the Mode control to the Music– position the frequency response
remains flat but the phase is reversed. Depending on the relative position of the
Diagram 3 - low pass options, music mode
sub-woofer and satellite speakers within the listening environment, phase reversal
can result in more consistent integration.The Music position is recommended for
music programme material. The response curves for each Low Pass filter position
with Music+ selected is shown on the control panel and in Diagram 3.
15dB
10dB
5dB
With the Mode control in the Theatre+ position the frequency response is lifted
in the 40 - 60Hz region. This boosted setting is designed to provide a more
0dB
demonstrative sub-woofer performance appropriate for audio/visual programme
-5dB
material. The response curves for each Low Pass filter position with Theatre+
-10dB
selected is shown on the control panel and in Diagram 4. The Theatre– position
-15dB
Off
200Hz
120Hz
60Hz
40Hz
retains the frequency response but reverses the phase.
10Hz
100Hz
1000Hz
Due to the nature of the electronics in ATC active loudspeakers it is quite normal
for a sound to be heard from the speaker when the power is applied or
disconnected. The noise heard will not damage the speaker and is quite normal.
Diagram 4 - low pass options, theatre mode
Although ATC uses the highest-grade components, a different noise may be heard
from each speaker due to slight tolarance variations in the amplifier components.
15dB
10dB
3.4
Listening
5dB
0dB
The ear and brain tend to interpret distorted sound as loudness and thus
-5dB
underestimate the actual level of undistorted sound. ATC sub-woofers, like all ATC
-10dB
products, demonstrate very much lower levels of distortion than conventional systems
Off
200Hz
120Hz
60Hz
40Hz
-15dB
of a similar size and it is therefore advisable to begin listening at an artificially low level
and carefully increase the volume. It is also possible for the ATC systems to produce
10Hz
100Hz
1000Hz
9
C1 Active
Specifications
C1 Active Sub-woofer
3.4
L i s t e n i n g c o n t ’d
sufficient sound pressure levels for your ears
themselves to become a source of distortion and
make the sound appear harsh. Any audible
distortion indicates that either the system or your
ears are being overloaded and that the volume level
should be reduced.
3.5 Care and Maintenance
High technology material finishes are used in this
product.The surfaces are durable and with a little
care can be kept as good as new even under
conditions of heavy use. Normally a dry duster will
Driver:
234mm (9")
Cut-off Frequencies
(-3dB free standing)
20Hz & 2kHz
Max Continuous SPL
112dB SPL @ 1 metre
Input Connectors
RCA Phono or Stripped cable
Input Sensitivity
1V Un-balanced (Phono input)
Input Impedance
>10k Ohms
Amplifier Output
Continuous
250 Watts RMS
Gain Control Range
±6dB
Theatre Equaliser
6dB lift @ 40 - 60Hz
Filter Characteristics
Preset or variable, 40 - 200Hz
Power Requirements:
100, 115, 230V, 50/60Hz
Cabinet Dimensions (HxWxD) 434 x 350 x 350mm
Overall Weight
20kg (44lb)
Cabinet Finish
Cherry, Rosewood
be all that is required to keep the finishes clean.
The above specifications comply with the following standards: Australian Standard Specification No 1127 "Sound System
Heavy soiling can be cleaned using a cloth slightly
Loudspeakers" Part 5, IEFE Specification Standard No 219-1975
moistened with a non-abrasive household cleaner.
ATC reserves the right to vary products and specifications without prior notice. Acoustic Transducer Co. is a trading name and ATC
is the registered trade mark of Loudspeaker Technology Ltd.
There are no components within the speaker that
can be considered expendable, or that would
benefit from regular maintenance. There is no
requirement for any kind of routine service work
and there is no schedule for preventative
maintenance. Should a speaker fail to switch on
when the power switch is operated the fuse
should be inspected. Lift out the fuseholder cover
using a small flat-blade screwdriver, remove the
fuse and inspect it for damage. If required, a spare
fuse may be supplied in the body of the fuseholder
cover. Fuses most often fail only because of a
serious electrical fault. If this is the case then
simply replacing the fuse will only result in another
3 . 6 Wa r r a n t y a n d C o n t a c t
All ATC products are guaranteed against any defect in materials or workmanship for
a period of two years from the date of purchase.Within this period we will supply
replacement parts free of charge provided that the failure was not caused by misuse,
accident or negligence.
fuse failure. The speaker should be returned to
ATC for service if a second fuse fails.
There are no user replaceable parts within the
speaker and in the unfortunate event of any
Purchasers who complete and return the Warranty Card will have their
warranty period extended up to a period of six years from the date of
purchase.This guarantee does not limit statutory rights.
malfunction, repair should be referred to either
ATC can be contacted at:
the supplying dealer or consultant, the relevant
Loudspeaker Technology Ltd, Gypsy Lane, Aston
importer, or ATC.
Down, Stroud, Gloucestershire GL6 8HR, UK.
Telephone:
10
01285 760561
Fax:
01285 760683
Email:
info@atc.gb.net
Website:
www.atc.gb.net
C2/C4/C6/C7 Active
Sub-woofer Installation
4.1 Sub-woofer Placement
The subjective performance of any sub-woofer will be fundamentally influenced by
the acoustic character of the room in which it is used, and its position within the
room. Monitor and sub-woofer systems are most often installed in rooms which are
comfortable to sit and talk in, and the typical mixture of carpets, curtains and soft
furnishings help ensure that middle and high frequencies are reasonably well
controlled.There may however be low frequency problems; either too much or too
little bass. To minimise these problems the sub-woofer should be kept away from
corners or walls. Start with it positioned around 1 metre from the side walls and 2
metres from the back. If the balance is bass-light, the sub-woofer can be moved
towards the corner. Use the sub-woofer controls to optimise satellite integration
and for fine tuning rather than to compensate for inappropriate positioning All
4.3 Signal Cable Options
Balanced cable configuration is the preferred
option, however unbalanced connection is
possible. Diagrams 2 and 3 illustrate the signal
cable connections required for each option.
Balanced (XLR to XLR) connection offers lower
noise and better immunity to “hum” pick-up.
Unbalanced (XLR to Phono or Two Pole Jack)
connection carries risk of hum caused by multiple
signal earths.
rooms vary and it is a good idea to experiment with both listening and speaker
Hum
positions until a good compromise is reached. If the sub-woofer is to be placed in
connection may be reduced by making ONE of the
any form of enclosure, adequate side and top clearance for cooling airflow must be
following modifications to the signal cable
provided. For professional installations the requirements are often very specific.
connections: If the driving preamplifier (or desk) is
Please consult with an experienced professional acoustician if necessary.
“double insulated” (i.e. has no mains earth),
More information on sub-woofer installation and use can be found later in Section 5.
problems
resulting
from
unbalanced
disconnect the signal cable screen at the RCA
Phono plug end. Alternatively, disconnect the signal
cable screen at the XLR end.This second option will
4.2 Connection
Either two or three cable connections are required for each subwoofer: one for mains power and one or two for the audio signal.
make the source the reference signal earth.
Diagram 1 - input connection pins
The mains cable is specifically supplied to comply with local statutory
safety approvals and alternatives should not be substituted. If you
intend to use your sub-woofer in an alternative territory please
contact ATC for advice. The mains connection must always be
Pin 2, Signal (hot)
Pin 1, Screen
Pin 3, Signal (return)
earthed.
The signal cable(s) and plug(s) should be of a good quality and XLR
terminated. Poor cable and plug quality will compromise the
performance of your sub-woofer.The signal input pin configuration is
illustrated in Diagram 1. If two signal connections are made to the
sub-woofer (i.e. a stereo pair) the left and right signals will be
Diagram 2 - balanced cable
summed by the amplifier so increasing the effective sensitivity by 6dB.
The mono sub-woofer signal from an audio-visual processor may be
connected to either left or right line-level XLR input.
3 Pin Male XLR
Connector
Two Core Screened Cable
3 Pin Female XLR
Connector
2
Hot
Return
2
1
Screen
1
3
To Monitor Input
3
To Source Output
Diagram 3 - unbalanced cable
3 Pin Male XLR
Connector
Phono (RCA)
Connector
Two Core Screened Cable
2
Hot
Return
1
Screen
3
To Monitor Input
To Source Output
11
C2/C4/C6/C7 Active
4.4
Sub-woofer Installation
Operation
The sub-woofer amplifier control and connection panel provides a range of
adjustment facilities to assist its integration with the satellite speakers.These facilities
are explained below and illustrated in Diagrams 4, 5 and 6.
Level: Sets the overall sensitivity of the sub-woofer. Initially the level control should
be set towards the centre of its range and only adjusted once the Low Pass and
Contour controls have been set.
Low Pass:Varies the upper crossover frequency as
Diagram 4 - connection and control panel
indicated on the control panel and Diagram 5.This
is the fundamental parameter that defines the
integration of the sub-woofer with the satellites.
The Low Pass control should be set at or slightly
above the specified low frequency cut-off of the
satellite speakers.
Contour: With the Contour control set to the
Flat+ position the sub-woofer pass-band frequency
response is fundamentally flat and in phase with the
satellite speakers.With the Contour control to the
Flat– position the frequency response remains flat
but the phase is reversed. Depending on the
relative position of the sub-woofer and satellite
speakers within the listening environment, phase
reversal can result in more consistent integration.
The Flat position is recommended for music programme material. The response
curves for each Low Pass filter position with Flat+ selected is shown in Diagram 5.
With the Contour control in the Lift+ position the frequency response is lifted in
Diagram 5 - low pass options, contour flat
the 40 - 60Hz region. This boosted setting is designed to provide a more
demonstrative sub-woofer performance appropriate for audio/visual programme
15dB
material.The response curves for each Low Pass filter position with Lift+ selected
is shown in Diagram 6. The Lift– position retains the frequency response but
10dB
5dB
reverses the phase.
Badge Indicator (C6 Only):The badge located on the lower front of the C6 cabinet
incorporates an amplifier status indicator. GREEN indication shows that the
0dB
RED indication shows that the amplifier is
-10dB
operating at the full available output. Any more than brief RED indication means
-15dB
amplifier is operating normally.
2kHz
90Hz
80Hz
70Hz
60Hz
50Hz
-5dB
that the amplifier is being over-driven and that its protection circuits are operating.
Protection will limit and distort the acoustic output of the sub-woofer so the
10Hz
100Hz
1000Hz
operating volume should be reduced.
Due to the nature of the electronics in ATC active loudspeakers it is quite normal
Diagram 6 - low pass options, contour lift
for a sound to be heard from the speaker when the power is applied or
disconnected. The noise heard will not damage the speaker and is quite normal.
15dB
Although ATC uses the highest-grade components, a different noise may be heard
10dB
from each speaker due to slight tolarance variations in the amplifier components.
5dB
0dB
4.5 Listening
2kHz
90Hz
80Hz
70Hz
60Hz
50Hz
-5dB
-10dB
The ear and brain tend to interpret distorted sound as loudness and thus
underestimate the actual level of undistorted sound. ATC sub-woofers, like all ATC
products, demonstrate very much lower levels of distortion than conventional systems
12
-15dB
10Hz
100Hz
1000Hz
C2/C4/C6/C7 Active
Specifications
C2 Active Sub-woofer
C4 Active Sub-woofer
C6 Active Sub-woofer
C7 Active Sub-woofer
Driver:
234mm (9”)
314mm (12")
375mm (15")
375mm (15")
Cut-off Frequencies:
(-3dB free standing)
18Hz & 250Hz
18Hz & 250Hz
18Hz & 250Hz
18Hz & 250Hz
Max Continuous SPL:
108dB SPL @ 1 metre
112dB SPL @ 1 metre
115dB SPL @ 1 metre
115dB SPL @ 1 metre
650 Watts
650 Watts
Input Connector:
2 x Male XLR
Input Sensitivity:
1.0V Balanced
Input Impedance:
Amplifier Output:
>10k Ohms
250 Watts
650 Watts
Gain Control Range:
±6dB
Contour Equaliser:
+6dB @ 40 - 60Hz
Filter Characteristics:
50Hz, 60Hz, 70Hz, 80Hz, 90Hz low pass second order critically damped
Power Requirements:
100, 115, 230V 50/60Hz
Cabinet Dimensions (HxWxD) 470 x 400 x 400mm
582 x 500 x 500mm
635 x 550 x 550mm
672 x 600 x 575mm
Overall Weight
46kg (101.4lb)
52g (114.6lb)
63.6kg (140.2lb)
70kg (154.3lb)
Cabinet Finishes
Black, Silver
Black, Silver
Cherry,Walnut, Rosewood
Silver (others to special order)
Specifications comply with the following standards: Australian Standard Specification No 1127 "Sound System Loudspeakers" Part 5,
IEFE Specification Standard No 219-1975
ATC reserves the right to vary products and specifications without prior notice. Acoustic Transducer Co. is a trading name and ATC
is the registered trade mark of Loudspeaker Technology Ltd.
4.5 Listening cont’d
of a similar size and it is therefore advisable to begin listening at an artificially low level
and carefully increase the volume. It is also possible for the ATC systems to produce
sufficient sound pressure levels for your ears themselves to become a source of
distortion and make the sound appear harsh. Any distortion indicates that either the
system or your ears are being overloaded and that the volume should be reduced.
4 . 7 Wa r r a n t y a n d C o n t a c t
4.6 Care and Maintenance
All ATC products are guaranteed against any defect
High technology material finishes are used in these products. The surfaces are
in materials or workmanship for a period of two
durable and with a little care can be kept as good as new even under conditions of
years from the date of purchase.Within this period
heavy use. Normally a dry duster will be all that is required to keep the finishes
we will supply replacement parts free of charge
clean. Heavy soiling can be cleaned using a cloth slightly moistened with a non-
provided that the failure was not caused by misuse,
abrasive household cleaner.
accident or negligence.
There are no components within the speakers that can be considered expendable,
or that would benefit from regular maintenance. There is no requirement for any
kind of routine service work and there is no schedule for preventative maintenance.
Should a speaker fail to switch on when the power switch is operated the fuse
should be inspected. Lift out the fuseholder cover using a small flat-blade
screwdriver, remove the fuse and inspect it for damage. If required, a spare fuse is
Purchasers who complete and return the
Warranty Card will have their warranty period
extended up to a period of six years from the
date of purchase.This guarantee does not limit
statutory rights.
supplied in the body of the fuseholder cover. Fuses most often fail only because of a
ATC can be contacted at:
serious electrical fault. If this is the case then simply replacing the fuse will only result
Loudspeaker Technology Ltd, Gypsy Lane, Aston
in another fuse failure. The speaker should be returned to ATC for service if a
Down, Stroud, Gloucestershire GL6 8HR, UK.
second fuse fails.
Telephone:
01285 760561
There are no user replaceable parts within the speakers and in the unfortunate
Fax:
01285 760683
event of any malfunction, repair should be referred to either the supplying dealer or
Email:
info@atc.gb.net
consultant, the relevant importer, or ATC.
Website:
www.atc.gb.net
13
System Installation
S p e a ke r Po s i t i o n i n g
5.1
Full Bandwidth
S p e a k e r Po s i t i o n i n g
While each loudspeaker in an AV system should be
located appropriately in its immediate acoustic
environment (see the positioning section in each
loudspeaker User Guide), if an AV system is to
reach its full potential the relative position of each
loudspeaker element must be considered.
In professional environments the relative position is
important because it will fundamentally influence
multichannel mix decisions, while in domestic
systems correct positioning will offer the best
chance of programme material being heard as
intended.
The basic guidelines for positioning the five full
bandwidth speakers of a 5.1 system are illustrated
in Diagram 1.The elements of an AV system should
follow this positioning guide as closely as possible.
There is some latitude for compromise
in the speaker to listener distance of a
domestic
installation
as
Diagram 1 - full bandwidth speaker positioning
AV
decoders/processors provide facilities
to adjust the delay time of all or some
speaker
channels.
Centre
Professional
installations however should adhere
Right Front
Left Front
strictly to the recommendations of
Diagram
1
and
not
adjustment
to
alternative
speaker
use
delay
compensate
to
for
listener
distances.
30˚
30˚
110˚
110˚
Listening Position
Left Surround
14
Right Surround
System Installation
Bass Management
5.2
Bass Management in Domestic Systems
•
High quality systems have enough dynamic
range and bass extension without the use of
This section aims to clarify some of the issues surrounding the use of Bass
Bass Management. Less software processing of
Management (or bass redirection as it sometimes known) in ATC multichannel
the source material implies less potential for
systems.Topics discussed apply to the whole range of ATC systems and can be used
undesirable artefacts.
for guidance when making installation decisions.
•
Differences in professional and domestic requirements dictate slightly different
High quality active speakers often have built-in
protection
approaches to Bass Management. In the recording studio, the primary aim is to
against
the
extreme
low
frequencies responsible for the majority of
achieve a result which will transport well to a range of domestic equipment and
undesirable
listening environments, whilst retaining the artistic intentions.These notes however
bass-related
effects
so
underminining the value of Bass Management.
focus on the needs of the domestic user which are rather more particular. The
This is the case for ATC active speakers.
primary function of Bass Management in domestic applications (home theatre or
multichannel audio only reproduction) is to increase the dynamic range, or the total
•
Without accurate knowledge of the acoustic
sound pressure that can be delivered by the speaker system. However, depending on
character of satellite and sub-woofer it is
the performance of the loudspeakers in use, this priority may not be appropriate in
impossible for Bass management to achieve a
some situations - this is commonly the case when using ATC loudspeakers. Switching
flat overall frequency response. Similarly the
off bass management in the majority of AV processors is simply a case of ensuring
phase response will be unpredictable.
that the Sub-woofer output is turned “ON” and that all satellite speaker size options
•
Bass Management encourages the crossover
are set to “LARGE”.
frequency between sub-woofer and satellites
The advent of multichannel reproduction technology in the home has led to the
to be above the onset of directionality in the
desire for inexpensive and robust speaker systems which can reproduce high sound
sub-woofer output. The resulting ability to
pressure levels. Unfortunately the latter two requirements are in direct conflict with
hear the location of the sub-woofer is clearly
the former. Obviously, the simplest way of reducing the retail price of a product such
to be avoided.
as a loudspeaker is to cut back on the quality of the components used. However,
•
When a significant proportion of the
when designed properly, there is a direct relationship between the cost of a moving
frequency range is separated from the
coil loudspeaker and its potential dynamic range.This can be attributed to a number
satellites and passed to the sub-woofer, any
of factors. For example, a drive-unit’s metal parts act as a sink for the heat generated
difference in the dynamic behaviour between
by its voice coil, so as the mass of steel used is reduced for cost purposes, so the
the two types of loudspeaker will cause the
speaker’s ability to handle power is degraded. Magnet size and diaphragm area also
system frequency response to change with
tend to be reduced in an attempt to cut costs. Again, the trade-off is efficiency and
output level.
dynamic range, both of which suffer as the compromises are made.
•
The addition of filter slopes to the existing
A convenient way of helping a low power system to deliver more sound pressure is
roll-off shapes of the loudspeakers may incur
to divert the potentially more damaging low frequencies away from the vulnerable
time-domain ringing and audible colouration.
speakers and into a sub-woofer. Bass management was devised to perform this task
in the digital domain. It is a system of software filters and gain controls commonly
fitted to AV processors/decoders that can redirect low frequencies away from the
satellite speakers (left, centre, right, surround left and surround right in a 5.1
configuration) and route it to the dedicated low frequency channel. Because the
processing is done in software it is virtually free of cost and thus attractive to those
who wish to maximise the dynamic range of a modest speaker system.
5.4
Conclusion
There is good argument for the use of Bass
Management in modest, cost sensitive systems
with restricted dynamic range. However, when
applied to high quality systems the side effects are
likely to be intrusive.We strongly recommend that
5.3
Bass Management Compromises
Bass Management should not be used with ATC
loudspeakers in domestic applications.
As described above, Bass Management was devised for domestic use as a means of
extracting more performance from cost-sensitive systems. However in high quality
audio systems it should be avoided. The improvement in dynamic range that may be
achieved with Bass Management is not without side effects and in high quality
systems these side effects are significant. The reasons for avoiding its use in high
quality systems, such as ATC systems, are these:
15
®
AC O U S T I C ENGINEERS
Loudspeaker Technology Ltd, Gypsy Lane, Aston Down, Stroud, Gloucestershire GL6 8HR United Kingdom
Telephone 01285 760561 Fax 01285 760683
Email: info@atc.gb.net Website: www.atc.gb.net