ATC C1, C3, C4, C5, C6 User Manual

AV Products

User Manual: Centre Channel Speakers: C1 • C3 • C4 • C5 • C6 • C7

Sub-woofers: C1 • C2 • C4 • C6 • C7

MULTICHANNEL

ACOUSTICENGINEERS

®

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

Safety Warnings

Welcome. In selecting ATC you have chosen an

example of the finest audio engineering

available. ATC was founded on a principle of

engineering excellence, and that principle still

defines our products today. Given the right

opportunities, ATC products will deliver

exceptional audio performance, but the

opportunities will only arise from careful and

thoughtful installation and use. Please read the

following manual fully. It will help you

understand the product and to realise its full

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

manual.

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
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 lev els 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.

AV Products

ATC has become synonymous with active systems. Choosing to offer active
loudspeakers (where the passive crossover network is replaced by active filters and
multiple power amplifiers) is simply a result of the uncompromising attitude to
loudspeaker design.While passive systems still have their place,and ATC engineering
skills can still bring remarkable results from them,“active” is a fundamentally better
solution to the problems posed by accurate,high level music reproduction.The ATC
instinct is always for the better solution.Not cheaper,not quicker,but better.

It was the development of active loudspeakers that first brought ATC into
electronics design and engineering. Active speakers demand multiple power
amplifiers so ATC from the mid 1980s became not just a loudspeaker manufacturing
company but an electronics manufacturer too.The further step from electronics for
active speakers to a range of stand-alone amplifier products was natural and now
means that ATC engineering is
available from the recording
desk or CD player output to
the ears.

From modest beginnings ATC
has grown to become one of
the very few manufacturers
successful across both
domestic and professional
audio. By selecting ATC you
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.

Introduction

2

Contents

Page 2 Introduction

Page 3 C4/C5/C6/C7 Active Centres

Section 1.1 Centre Speaker

Placement

Section 1.2 Connection

Page 4 Section 1.3 Signal Cable Options

Section 1.4 Operation
Section 1.5 Listening

Page 5 Section 1.6 Care and Maintenance

Section 1.7 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 Care and Maintenance

Section 2.6 Warranty and Contact

Specifications

Page 8 C1 Active Sub-woofer

Section 3.1 Sub-woofer Placement
Section 3.2 Connection

Page 9 Section 3.3 Operation

Section 3.4 Listening

Page 10 Section 3.5 Care and Maintenance

Section 3.6 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 Operation

Section 4.4 Listening

Page 13 Section 4.6 Care and Maintenance

Section 4.7 Warranty and Contact

Specifications

Page 14 System Installation Notes

Section 5.1 Full Bandwidth Speaker

Positioning

Page 15 Section 5.2 Bass Management in

Domestic Systems
Section 5.3 Bass Management

Compromises
Section 5.4 Bass Management

Conclusions

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 ma y 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 pictur e 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.

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
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

Diagram 1 - input connection pins

Pin 1,ScreenPin 2,Signal (hot)

Pin 3,Signal (return)

Centre Speaker Installation

1.3 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.

Hum problems resulting from unbalanced
connection may be reduced by making ONE of the
following modifications to the signal cable
connections: If the driving preamplifier (or desk) is
“double insulated” (i.e. has no mains earth),
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 make
the source the reference signal earth.

Installation

4

C4/C5/C6/C7 Active

1.4 Operation

The C4,C5,C6 and C7 are connected to the mains and signal cables via sockets on
the rear panel. The rear panel also carries the mains switch and fuse holder. Each
feature is described below.

• 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
(above the input socket) corresponds with the local supply.

• Power Switch:Switches on the speaker.When switched on the indicator on the
back of the monitor will illuminate (C6 & C7 only).

• Fuseholder: 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. It
should be stressed however that 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 fuse failure. The monitor should be returned to ATC for service if a
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
power is applied or disconnected.The noise heard will not damage
the speaker and is quite normal. Although ATC uses the highest­grade components, a different noise may be heard from each
speaker due to slight tolarance variations in the amplifier
components.

1.5 Listening

The ear and brain tend to interpret distorted sound as loudness
and thus underestimate the actual level of undistorted sound.The
C4, C5, C6 and C7, like all ATC monitors, demonstrate very much
lower levels of distortion than conventional 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 C4, C5, C6 or C7 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.

Diagram 2 - balanced cable

Diagram 3 - unbalanced cable

Two Core Screened Cable

3 Pin Male XLR

Connector

3 Pin Female XLR

Connector

To Monitor Input

Hot

Return
Screen

To Source Output

1

2

3

1

2

3

Two Core Screened Cable

3 Pin Male XLR

Connector

Phono (RCA)

Connector

To Monitor Input

Hot

Return
Screen

To Source Output

1

2

3

Centre Speakers

C4/C5/C6/C7 Active

1.6 Care and Maintenance

High technology material finishes are used in these products. The surfaces are
durable and with a little care can be kept as good as new even under conditions of
heavy use. Normally a dr y duster will be all that is required to keep the finishes
clean. Heavy soiling can be cleaned using a cloth slightly moistened with a non­abrasive household cleaner.

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 prev entativ e 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 fuse failure.The speaker should be returned to ATC for service if
a second fuse fails.

There are no user replaceable parts within the speakers and in the unfortunate
event of any malfunction,repair should be referred to either the supplying dealer or
consultant,the relevant importer, or ATC.

5

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.

Drivers:

HF 25mm (1") 25mm (1") 25mm (1") 25mm (1")
MF 75mm (3") 75mm (3")
LF 2 x 125mm (5”) 2 x 150mm (6”) 2 x 234mm (9") 2 x 234mm (9")

Amplitude Linearity ±2dB 75Hz – 20kHz 75Hz – 12kHz 50Hz – 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

Dispersion:

Horizontal ±10° Coherent ±10° Coherent ±60° Coherent ±60° Coherent

Vertical ±80° Coherent ±80° Coherent ±10° 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

Amplifier Output:

LF 200 Watts RMS 200 Watts RMS 200 Watts RMS 200 Watts RMS

MF 100 Watts RMS 100 Watts RMS

HF 50 Watts RMS 50 Watts RMS 50 W atts RMS 50 Watts RMS
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 100, 115, 230V 100, 115, 230V 100, 115, 230V 100, 115, 230V

Frequency 50/60Hz 50/60Hz 50/60Hz 50/60Hz
Cabinet Finishes Black/Silver Black/Silver Cherry,Walnut, Rosewood Black/Silver

veneers standard.Others to Others to special order
special order.

C4 Active Centre C5 Active Centre C6 Active Centre C7 Active Centre

Specifications

1.7 Warranty and Contact

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.

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.

ATC can be contacted at:
Loudspeaker Technology Ltd, Gypsy Lane,Aston

Down,Stroud,Gloucestershire GL6 8HR, UK.
Telephone: [phone]
Fax: [phone]
Email: [e-mail]
Website: www.atc.gb.net