ATC HIFI Series User manual

Loudspeaker Technology Ltd
Gypsy Lane
Aston Down
Stroud
Gloucestershire
GL6 8HR
United Kingdom
Telephone [phone]
Email: [e-mail]
Website: www.atc.audio
Acoustic Transducer Company is the trading name.
is the registered trade mark of Loudspeaker Technology Ltd.
HIFI SERIES
C4 Sub M k 2
12” SUBWOOFER |MANUAL

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, wash bowl, 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, 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 ow 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 qualied 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 qualied service personnel. Please contact your local ATC dealer or distributor.
15 Grounding or polarisation – precautions should be taken so that grounding or polarisation means for the appliance are not defeated.
SECTION ONE
1.1 Welcome
SECTION TWO
2.1 Product Description
SECTION THREE
3.1 Room Interaction
3.2 Subwoofer Placement
SECTION FOUR
4.1 Connection
4.2 Signal Cable Options
SECTION FIVE
Control Panel Operation
5.1 Power on/o
5.2 Level and Gain
5.3 Polarity and Phase
5.4 Frequency
5.5 Outputs
5.6 Footswitch – Input and Thru
5.7 Fault
SECTION SIX
6.1 Typical System Congurations and Recommendations
6.2 Bass Reinforcement/Bass Extension of a Stereo System
6.3 Multichannel Surround/Immersive Audio
SECTION SEVEN
7.1 L i s t e n i n g
SECTION EIGHT
8.1 Care and Maintenance
SECTION NINE
Specication
9.1 Acoustic
9.2 Electronic
9.3 Physical
SECTION TEN
10 .1 Wa r r a n t y
10.2 Contact
SAFETY WARNINGS
CONTENTS

In selecting ATC you have chosen an example of the nest audio engineering available. ATC was founded on a principle of engineering excellence, and
that principle still denes 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 oer 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 Billy Woodman. 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 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 oer the best of both. It’s an easy concept to describe, but surprisingly dicult to engineer.
The diculty inherent in designing such loudspeakers is one of scale. Hi 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 motor sport. But the results are worth the eort and the cost. ATC loudspeakers, with their unique in-house designed drivers,
combine the best of hi and professional to devastating eect.
ATC has become synonymous with active systems. Choosing to oer active loudspeakers (where the passive crossover network is replaced by
active lters and multiple power ampliers) 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 rst brought ATC into electronics design and engineering. Active speakers demand multiple
power ampliers 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 amplier 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.
SECTION ONE
Welcome
1.1

The ATC C4 Sub Mk2is a high-performance 12”/300mm active subwoofer, designed from the ground up to deliver the exceptional levels of
performance required to partner ATC’s active and passive loudspeaker range. Its performance and features make it ideally suited to use within
stereo, multi-channel surround and immersive audio systems.
The sub features a sealed-box (innite bae) design, chosen for its balance of sub-bass extension and driver control. The cabinet is heavy and inert
to minimise cabinet colouration.
The S S 7 5 - 314 S C driver employed has been meticulously optimised to reproduce the lowest 3 octaves of the audio band within the design of the
C4 Sub Mk2subwoofer system. It employs a short-coil operating in an exceptionally long magnetic gap to deliver high sound pressure levels with
very low levels of distortion.
The C4 Sub Mk2’s convection cooled amplier is mounted in the rear of the cabinet. Two balanced Inputs enable connection to mono or stereo
sources. A pair of buered, un-ltered balanced Outputs provide connection to partnering active monitor loudspeakers, ampliers or to daisy
chain multiple subs. 21d B range of gain control, three low pass frequency settings, polarity switch and a18 0 degree continuously variable phase setting
allow the user to optimise the subwoofer for use with a very wide range of partnering loudspeakers. The low pass lter can also be set to ‘O’
(320Hz) should the user wish to use the C4 Sub Mk2with external processing. The amplier features fault monitoring of amp panel temperature
and power amplier DC oset and either fault condition is indicated via illumination of a single red LED mounted on the amp panel.
When in use, the subwoofer output can be muted using a single latching footswitch connected via a ¼”/6.35mm jack. The mute function does not
aect the Outputs to the primary loudspeakers, only the output from the sub itself. Additional subs can be muted using the same single footswitch
via connection to the mute ‘Thru’ jack.
Product Description
2 .1
SECTION TWO

The room in which a loudspeaker is placed can be thought of as a lter, altering the acoustic response at the listening position from that of the
loudspeaker. The position of the loudspeaker in a room will inuence how it interacts with the space and therefore is often critical to achieving the
best performance at the listening position.
Positioning is particularly relevant to subwoofers because at low frequencies the room will have a strong inuence due to room modes/resonances.
Room modes manifest themselves in an uneven distribution of acoustic energy within the room, which can lead to either too much or too little
bass at the listening position. A room with a well-controlled low frequency response (reverb time) will have a far smaller influence on the
performance of the subwoofer and will be less sensitive to subwoofer positioning. Applying acoustic treatment in a domestic setting is not always
possible or desirable but if considered it should be noted that typically, a combination of resonant membrane traps and porous absorbers are needed
to control the low frequency. The resonant membrane traps are eective at treating the low bass, typically below 80Hz and the porous absorbers
frequencies above this. Porous absorbers such as those made from foams, breglass or rockwool are not eective at absorbing low bass energy
without a very large air space between them and the wall behind. For this reason, they are a poor choice of absorber for the subwoofer bandwidth.
To minimise problems a free-standing subwoofer should be kept away from corners where possible. Avoid placing the subwoofer mid-way between
any two parallel walls.
The C4 Sub Mk2is supplied with 4 x steel spikes which can be tted to the threaded holes in the base of the subwoofer. The spikes are optional
and can be tted to ensure the subwoofer is seated rmly when positioned on a soft carpeted oor. Without the spikes tted, the subwoofer will
sit on the 4 x xed rubber feet, which is ideal for hardwood/concrete ooring.
Start with the subwoofer positioned next to one of the stereo monitors and at the same distance from the listening position. When installing
two subwoofers, start with one by each of the stereo monitors. In most cases these guidelines will give the best results, however all rooms vary,
and it is a good idea to experiment with both listening and speaker positions until a good compromise is reached. When working on optimising the
positioning, only change one variable at a time.
Positioning the subwoofer in the centre of the room, equidistant from the two side walls and between the left and right stereo pair must be avoided.
In the majority of cases, this position will result in large irregularities in the frequency response.
Multiple subs will excite the room from multiple locations and will often give a more even in-room response. Also, a pair of subs can be placed with
the same physical relationship to the pair of main speakers and the listener.
Please see section 5 for recommendations on how to set the amplier lters and level.
SECTION THREE
Room Interaction
3.1
Subwoofer Placement
3.2

Either two or three cable connections are required for each subwoofer: one for mains power and one or two for the audio signal. The mains cable
is specically supplied to comply with local statutory safety approvals and alternatives should not be substituted. If you intend to use your subwoofer
in an alternative territory, please contact ATC for advice. The mains connection must always be 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
subwoofer. The signal input pin conguration is illustrated in Diagram 1. If two signal connections are made to the subwoofer (i.e. a stereo pair) the
left and right signals will be summed by the amplier, increasing the eective input level to the amplier stage by 6dB.
Balanced cable conguration 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 oers 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 modications to the signal cable connections:
If the driving preamplier (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.
SECTION FOUR
Connection Signal Cable Options
4.1 4.2
DIAGRAM 1 DIAGRAM 2
DIAGRAM 3

The subwoofer amplier control and connection panel, shown in Diagram 4, provides a range of functions to assist with system integration.
These are explained opposite.
Powers the subwoofer on or o. When the button is in the inward position, the loudspeaker is powered on. When the button is in the outward
position, the subwoofer is powered o.
Sets the overall sensitivity of the subwoofer. Initially, the Level control should be set towards the centre of its range and only adjusted once the
Frequency has been set. If one Input is connected, start with the Gain switch set at +6dB. If both Inputs are connected, start with the Gain switch
set at 0dB.
An additional +10dB gain setting is included for situations where the preceding equipment can only deliver a low output level. Please note that
increasing the gain does not increase the maximum acoustic output capability of the system.
Please refer to Section 9 – Product Specications for information on system sensitivity.
Sets the overall polarity of the subwoofer and oers an adjustment of the input/output phase. When set to + and 0° the subwoofer will radiate a
positive acoustic pressure for a positive electrical signal at the Input. When set to – and 0° the subwoofer will radiate in the opposite polarity to
the Input. The Phase control allows for ne adjustment of the phase relationship between subwoofer and satellite speakers. This can be thought of
as a delay, allowing for time alignment with other system elements and is useful when physical adjustment of loudspeaker/sub position is limited.
Varies the low pass crossover Frequency as indicated on the control panel. This is the fundamental parameter that denes the integration of the
subwoofer with the satellites. The Frequency control should be set at, or slightly above the specied low frequency cut-o of the satellite speakers.
The “open” setting applies a low pass lter at 320Hz. Select this setting if you will apply the sub low pass crossover lter via an external processor.
All lters are of the type 4th order Linkwitz Riley.
Provides separately buered and fully balanced Outputs with a signal identical to that at the corresponding Input terminals. The Output is unltered
and unaltered in any way, and therefore it is possible to drive a stereo amplier or pair of active loudspeakers from these terminals. Likewise, it is
also possible to drive a second C4 Sub Mk2from these Outputs. This function allows for an unlimited number of C4 Sub Mk2s to be daisy chained
together, one driving the next.
SECTION FIVE
Power on/off
5.1
Level and Gain
Polarity and Phase
Frequency
Outputs
5.2
5.3
5.4
5.5
WARNING
!
Acoustic Transducer Co. Is a trading name and
Is the registered Trade Mark of Loudspeaker Technology Ltd.
RETURN TO
MANUFACTURER
FOR DISPOSAL
Fuse:
115V : T5A H/250V
220-230V : T3.15A H/250V
THERE ARE NO USER SERVICEABLE PARTS INSIDE
CONSUMPTION
MAINS INPUT
50/60 Hz
POWER
500 WATTS MAX.
CHECK VOLTAGE BEFORE USE
Fault
Inputs Outputs
Left
Right
Left
Right
0o
180o
Frequency Phase
Level (dB) Gain (dB)
O
80Hz
65Hz
50Hz
0
-1
-2
-3
-4
-5
-6
-7
-8
-9
-10
-11
0
+6
+10
High Performance
Active Subwoofer
Power
Designed and manufactured by
Acoustic Transducer Company,
Gloucestershire,
GL6 8HR, England
Input Thru
Footswitch
+
-
Pol.
+10dB - LFE calibration only
+6dB - single input driven
0dB - stereo inputs driven
Serial No.
Voltage
Model
THIS EQUIPMENT
MUST BE EARTHED
RISK OF ELECTRIC SHOCK
DO NOT OPEN
CAUTION
DIAGRAM 4

Facilitates remote muting of the subwoofer with the addition of a standard latching footswitch (not supplied, see specication). If the system includes
more than one C4 Sub Mk2, a second subwoofer can be controlled from the Thru Output socket. This allows for all subwoofers in a system to be
controlled simultaneously from one footswitch. The signal at the Output sockets is not aected.
Indicates a temporary or permanent amplier fault. The Fault LED will illuminate if there is a DC fault on the amplier or if the thermal limit of the
heatsink is reached. In the rare case that the Fault LED illuminates, the subwoofer should be switched o. Ensure the subwoofer heatsink has
adequate ventilation and after 45 minutes switch it back on. If the Fault LED remains illuminated the amplier is registering a fault which should be
investigated by an approved technician. Please contact your ATC dealer or distributor, details can be found at www.atc.audio. If the Fault LED is no
longer illuminated, the amplier had shut down safely due to reaching high temperatures. Please reduce the system listening level, subwoofer Level
or improve amplier ventilation and continue to use the subwoofer.
SECTION FIVE
Fault
5.7
Footswitch – Input and Thru
5.6

Diagram 5 – Typical Conguration – Stereo playback (Mono Sub). A preamplier or AV receiver Output is connected to the L and R Inputs of the
subwoofer. The subwoofer L and R Outputs are connected to the Input of the L and R main stereo amplier or active loudspeakers. In this
conguration the Gain switch is normally set to 0dB.
Diagram 6 – Typical Conguration – Stereo playback (Stereo Subs). A preamplier or AV receiver Output is connected to a single Input on each
subwoofer. The corresponding Output of each subwoofer is connected to the Input of the main power amplier/active loudspeaker on that channel.
In this conguration, the Gain switch is normally set to 0dB. Note that it is also possible to connect the preamplier/AV receiver Output to both
Left and Right channel Inputs on the subwoofer using aY-Splitter cable. If connected in this way the“spare”Output can be used to connect further subwoofers.
DIAGRAM 6
It is likely that a subwoofer will be used in one of two dierent scenarios: either as Bass Reinforcement/Extension in a Stereo System or as a discrete
channel in a Multichannel Surround/Immersive Audio system.
Typically, a full-range stereo signal is driven into both Left and Right subwoofer Inputs. The subwoofer Outputs connect to and drive the main
loudspeakers. Alternatively, the C4 Sub Mk2and main loudspeakers can be driven independently from a suitable preamplier/AV receiver. Example
systems are shown in Diagrams 5, 6 and 7. All subwoofers can be controlled using the method described in section 5. All panel settings should be
set independently for each subwoofer.
All ATC loudspeakers deliver signicant low frequency output, more so with the larger monitors in the range, therefore there will always be some
degree of acoustic overlap between the subwoofer and stereo loudspeaker in this conguration. Applying an external high pass lter to the main
loudspeakers will introduce phase shift in the main loudspeakers and should be avoided where possible. Good results can be achieved through
experimentation with the subwoofer Level, Frequency and Phase adjustment.
A selection of common wiring congurations are shown but other congurations exist, please contact your reseller or ATC for advice.
Typical System Configurations and Recommendations
Bass Reinforcement/Bass Extension of a Stereo System
6 .1
6.2
SECTION SIX
DIAGRAM 5
SUBWOOFER CONNECTED IN SERIES
SUBWOOFER CONNECTED IN SERIES

Diagram 7 and 8 – 2.1 Conguration – The subwoofer is driven by a preamplier/AV receiver with a second pre-amplier Output or dedicated
subwoofer Output. Additional subwoofers may be daisy chained using the subwoofer Outputs, or connected in a stereo conguration as shown.
DIAGRAM 7
DIAGRAM 8 SUBWOOFER CONNECTED IN PARALLEL, PASSIVE SYSTEM
SUBWOOFER CONNECTED IN PARALLEL
The recommended initial settings are shown opposite in Diagram 9.
The recommended number of subwoofers required in each system is shown in Diagram 10.
SECTION SIX
* In case of a passive system the required subwoofer gain setting will depend on the gain of the amplier used. Example shown is based on the ATC P1.
Loudspeaker model (pair)
BASS REINFORCEMENT/
EXTENSION OF STEREO
SYSTEM
SCM40 50Hz-6dB* 6dB/0dB* 0° +
SCM40A 50Hz-6dB 6dB/0dB 0° -
SCM20PSL 65Hz-6dB* 6dB/0dB* 0° +
SCM50ASL 50Hz-6dB 6dB/0dB 0° -
SCM20ASL 65Hz-6dB 6dB/0dB 0° +
SCM100PSL 50Hz-3dB* 6dB/0dB* 0° +
SCM150PSL 50Hz 0dB* 6dB/0dB* 0° +
SCM50PSL 50Hz-6dB* 6dB/0dB* 0° +
SCM100ASL 50Hz-3dB 6dB/0dB 0° -
SCM150ASL 50Hz 0dB 6dB/0dB 0° -
FREQUENCY
LEVEL
ADJUST FOR BEST
BALANCE
GAIN SWITCH
(SINGLE SUB /
DUAL SUBS)
PHASE
ADJUST TO
FINE TUNE
POLARITY
Subs
C4 SUB Mk2 1111-2 2
SCM40 SCM20SL PRO SCM50SL SCM100SL SCM150SL
Stereo loudspeakers
C4 Sub Mk2 – recommended initial settings
For detailed recommendations, please contact your dealer/distributor or ATC .
DIAGRAM 10
DIAGRAM 9

DIAGRAM 13
A single subwoofer is driven from the 0.1/LFE channel Output of a multichannel processor/monitor controller. For increased dynamic range and
headroom, multiple subwoofers can be connected in series as described in Section 5.5and 5.6. All panel settings must be set independently for
each subwoofer.
The choice of loudspeaker model and the number of subwoofers required in any system is dependent on room size, mix format and target
calibration level at the listening position. Diagram11 can be used as a guide to determine suitable partnering system elements from the ATC HiFi
product range.
• = Recommended. O = Acceptable. For detailed recommendations, please contact your dealer/distributor or ATC.
Surround
loudspeakers/subs
SCM20SL • • O
SCM50SL • • O
SCM40 O•O
SCM100SL • •
SCM150SL •
C4 SUB Mk2 11-2 22-4 4
SCM20SL SCM40 SCM50SL SCM100SL SCM150SL
SECTION SIX
Left/centre/right loudspeakers
80Hz-6dB 0dB 0° +
FREQUENCY
LEVEL
ADJUST FOR BEST
BALANCE
GAIN
PHASE
ADJUST TO FINE
TUNE INTEGRATION
POLARITY
C4 Sub Mk2 – recommended initial settings
when used in a multichannel system
Multichannel Surround/Immersive Audio
6.3
DIAGRAM 11
DIAGRAM 12
Recommended initial settings for the C4 Sub Mk2 when used in a multichannel system are shown in Diagram 12.
Diagram 13 – Typical Multichannel System wiring. Depending on the AV receiver Output level and number of subwoofers, the Gain switches may
need to be set to 6dB. Further subwoofers can be added to the system by connecting them in a daisy chain using the subwoofer Output sockets.
The system shown is an example and other congurations are available.

The ear and brain tend to interpret distorted sound as loudness and thus underestimate the actual level of undistorted sound. ATC subwoofers,
like all ATC products, demonstrate very much lower levels of distortion than conventional systems of a similar size and it is therefore advisable to
begin listening at an articially low level and carefully increase the volume. It is also possible for the ATC systems to produce sucient 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.
When a subwoofer is successfully integrated into a system it should become impossible to discern from the main loudspeakers. If the subwoofer
is audible as a separate element, then it is likely the level is too high, the lter settings require adjustment, or the positioning can be improved. Please
refer to Section 5 of this manual.
High technology material nishes 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 nishes clean.
Heavy soiling of the cabinet or bae can be cleaned using a cloth slightly moistened with a non-abrasive household cleaner. Dust can carefully be
removed from the drive unit with the use of a dry, lint free cloth.
There are no components within the speakers that can be considered expendable, or that would benet from regular maintenance. There is no
requirement for any kind of routine service work and there is no schedule for preventative maintenance. 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 consultant, the relevant
importer, or ATC . ATC has every condence in the quality of each product that it manufactures.
Low Frequency Cut-o: 22Hz (-6dB, half space, low pass lter set at 80Hz).
Low Pass Filters: 50Hz, 65Hz, 80Hz, 320Hz. (-6dB, 4th order Linkwitz Riley).
MaxSPL: 11 0 dBcontinuous,11 6 dBpeak (IEC Weighted Pink Noise, measured at 1m, half space, low pass lter set at 80Hz).
Sensitivity: +4dBu ref. 88dBC (single channel driven, measured at 1m, Gain +6dB, Level 0dB, pink noise, low pass lter set at 80Hz).
Amplier type: Grounded Source MOSFET based Class A-B, convection cooled.
Output Power: 300W in to 8Ω.
THD+N: <0.003%/-90dB, at 10 0 H z, 300W into 8Ω over 90kHz bandwidth.
Input CMRR: 90dBat 200Hz.
Input Impedance: Approx. 20kΩ(dierential).
Line Output Impedance: Approx. 100Ω (dierential).
Frequency Response: <2Hz (-3dB) – 320Hz (-6dB, set by panel-controlled LP lter).
Low Pass Filters: 4th Order Linkwitz Riley.
Gain Control: 0, +6dB, +10 dB.
Level Control: 0dB-11 dBin 1dBsteps. Total range 21dBwith use of Gain switch.
Phase Control: 0-180° ref. Input.
Polarity Control: In-phase/Out-of-phase ref. Input.
Limiter: ATC Active FET Momentary Gain Reduction.
Sensitivity: 1.55Vrms for full power (single channel driven, Gain 0dB, Level 0dB).
Power Consumption: Idle 8W / 14 VA , 1/8th Power 17 0 W / 230VA, Full Power 500W / 600VA.
Mains Input: 220-230V, 115V – Factory set. Please observe panel markings and labels.
Additional: Mute via ¼”/ 6.35mm Jack socket, controlled via latching footswitch.
Listening
Care and Maintenance
7.1
8 .1
SECTION SEVENSECTION EIGHT SECTION NINE
Acoustic specification
Electronic specification
9.1
9.2

SECTION NINE
Physical specification
9.3
C4 Sub Mk2 WEIGHT – 42KG |DIMENSIONS – SEE DIAGRAM
22
3 8
"
568
18
5
16
"
465
19
16
"
40
20
7
16
"
519
17
9
16
"
446
A
77
8
"
200
7 8
"
22
(MIN)
22
3 8
"
568
18
5
16
"
465
19
16
"
40
20
7
16
"
519
17
9
16
"
446
A
77
8
"
200
7 8
"
22
(MIN)
22
3 8
"
568
18
5
16
"
465
19
16
"
40
20
7
16
"
519
17
9
16
"
446
A
77
8
"
200
7 8
"
22
(MIN)
Fixed rubber foot (x4)Optional screw-in metal spike (x4 supplied)
22
3 8
"
568
18
5
16
"
465
19
16
"
40
20
7
16
"
519
17
9
16
"
446
A
77
8
"
200
7 8
"
22
(MIN)
DETAIL A
SCALE 1:5
22
3 8
"
568
18
5
16
"
465
19
16
"
40
20
7
16
"
519
17
9
16
"
446
A
77
8
"
200
7 8
"
22
(MIN)
22
3 8
"
568
18
5
16
"
465
19
16
"
40
20
7
16
"
519
17
9
16
"
446
A
77
8
"
200
7 8
"
22
(MIN)

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 the Product Registration process, either by returning a completed Warranty Card to ATC or by registering the product at
www.atc.audio, 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.
Loudspeaker Technology Ltd
Gypsy Lane, Aston Down
Stroud, Gloucestershire
GL6 8HR
United Kingdom
Telephone [phone]
Email: [e-mail]
Website: www.atc.audio
Acoustic Transducer Company is the trading name and is the registered trade mark of Loudspeaker Technology Ltd.
Warranty
Contact
10.1
10.2
SECTION TEN
R