Meridian C52 User manual

IMPORTANT: PLEASE READ THIS COMPLETE MANUAL TO ENSURE PROPER
INSTALLATION AND OPERATION.
INSTALLERS: Please review this manual carefully before contacting Technical Support.
PRODUCT OWNERS: Please contact your authorised Meridian dealer for product or installation
questions.
Meridian C Series
Installation Components
C52
Dual Active Subwoofer Controller
Installation and Operation Manual

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3
CONTENTS
IMPORTANT SAFETY INSTRUCTIONS ..............................................................................................4
SERVICE AND GUARANTEE............................................................................................................5
ABOUT THE PRODUCT...................................................................................................................6
C52 SPECIFICATIONS .....................................................................................................................6
INSTALLATION AND SETUP.............................................................................................................7
CONNECTING THE C52..................................................................................................................8
CONFIGURING THE C52...............................................................................................................10
TROUBLESHOOTING ....................................................................................................................11
Please review the instructions in the following pages of this manual to help insure a smooth
installation and a happy customer.
Copyright © 2007 Meridian Audio Limited. No part of this document may be copied, photocopied, translated, or
reproduced to any electronic medium or machine readable form without prior consent, in writing, from Meridian.
Specifications subject to change without notice. All Rights Reserved.

4
IMPORTANT
SAFETY INSTRUCTIONS
• Readtheinstructions.
• Keeptheseinstructions.
• Followallinstructions.
• Donotusethisapparatusnearwater.
• Cleanonlywithadrycloth.
• Installonlyinaccordancewithmanufacturer’s
instructions.
• Referallservicingtoapprovedservicepersonnel.
This apparatus has been designed with Class
1 construction and must be connected to a
mains socket outlet with a protective earth
connection (the third grounding prong).
Do not defeat the safety purpose of the
polarized or grounding-type plug. A polarized
plug has one prong wider than the other. A
grounding type plug has two blades and a
third grounding prong. The wide blade or the
third prong are provided for your safety. If the
provided plug does not fit into your outlet,
consult an electrician for replacement of the
obsolete outlet.
WARNING:TOREDUCETHERISKOFFIRE
ORELECTRICSHOCK,DONOTEXPOSETHIS
APPARATUS TO RAIN OR MOISTURE
This apparatus uses a single-pole power
switch. As a result it is not isolated from AC
mains power when switched off at the rear
panel. The apparatus may be isolated from
mains power either by unplugging the power
connector from the rear of the unit, or by
unplugging the connector at the opposing
end of the power cord or cable from its supply
outlet. As a result, either or both of these
connectors should remain accessible.
Safety warnings
• Donotexposetheunittodrippingorsplashing.
• Donotplaceanyobjectlledwithliquid,such
as a vase, on the unit.
• Donotplacenakedamesources,suchas
lighted candles, on the unit.
To avoid interference
Do not position the unit:
• Nearstrongmagneticradiation.
• Neartoatelevision,orwhereconnectingcables
may be subject to or cause interference.
To avoid overheating
• Leaveatleast10cmaroundtheequipmentto
ensure sufficient ventilation.
Do not position the product:
• Indirectsunlight.
• Nearheatsources,suchasaradiator.
• Stackedwithanyotheraudioproductsother
than in a properly ventilated rack, as the heat it
generates may damage the other products.
The sides and top of the C52 case contain
venting holes for the internal heatsinks which
should not be obstructed. Ensure that air can
owaroundthem.Theproductnormallyruns
warm to the touch when not in standby.
Warning: The C52 is moderately heavy; take
care when lifting it.
Radio interference
FCC Warning: This equipment generates
and can radiate radio frequency energy
and if not installed and used correctly in
accordance with our instructions may cause
interference to radio communications or radio
and television reception. It has been type-
tested and complies with the limits set out in
Subpart J, Part 15 of FCC rules for a Class B
computing device. These limits are intended
to provide reasonable protection against such
interference in home installations.
EU: This product has been
designed and type-tested to
comply with the limits set out in
EN55013 and EN55020.

5
Warning: live terminals
Terminals marked with the ‘lightning
ash’symbolarehazardousliveandthe
externalwiringconnectedtothese
terminals requires installation by an
instructed person or the use of ready-
made leads or cords.
Information for Users on Disposal of
Old Equipment (EU Only)
Attention:
This symbol is only
valid in the European
Union.
[European Union]
This symbol indicates that the electrical and
electronic equipment should not be disposed
as general household waste at its end-of-
life. Instead, the product should be handed
over to the applicable collection point for the
recycling of electrical and electronic equipment
for proper treatment, recovery and recycling
in accordance with your national legislation.
By disposing of this product correctly, you will
help to conserve natural resources and will
help prevent potential negative effects on the
environment and human health which could
otherwise be caused by inappropriate waste
handling of this product. For more information
about collection point and recycling of this
product, please contact your local authority,
your household waste disposal service or
the shop where you purchased the product.
Penalties may be applicable for incorrect
disposal of this waste, in accordance with
national legislation.
(Business users)
If you wish to dispose of this product, contact
your Meridian dealer or distributor or Meridian
Audio Ltd to obtain information about the
take-back of the product.
[Other Countries outside the European
Union]
If you wish to dispose of this product, please
do so in accordance with applicable national
legislation or other rules in your country for
the treatment of old electrical and electronic
equipment.
Accessory Kit
The following items are supplied with C52
Dual Subwoofer Controller
1 - This manual
1 - Power Cord
Cables for connection to a Meridian Digital
Theatre System.
SERVICE AND GUARANTEE
Service
The Meridian components have been carefully
designed to give years of untroubled service.
There are no user-serviceable parts inside the
case, nor do the units require any form of
maintenance.
In the unlikely event that your subwoofer fails
to function correctly, it should be returned, in
its original packaging, to your Meridian dealer.
IncaseofdifcultywithintheUKorUSA
please contact Meridian Audio Limited or
Meridian America Inc respectively.
IncaseofdifcultyoutsidetheUKorUSA,
contact the importing agent for the territory. A
list of Meridian agents abroad is available from
Meridian.
No responsibility can be accepted for the
subwoofer whilst in transit to the factory or an
agent, and customers are therefore advised to
insure the unit. When seeking service under
guarantee, proof of the date of purchase will
be required.
Guarantee
Each unit is guaranteed against defects in
material and workmanship for two years from
the date of purchase.
The guarantee is void if the unit has been
subject to misuse, accident, or negligence,
or has been tampered with or modified in
any way without the written authorisation of
Meridian Audio Limited.
Note: Connecting anything other than the

6
correct network lead to the COMMS sockets
may cause damage to the subwoofer which
will not be covered by this guarantee.
Attempted servicing by unauthorised people
may also invalidate this guarantee. Labour and
carriage charges are not covered unless by
local agreement.
OutsidetheUK,localwarrantyliabilityis
restricted to equipment purchased within
the territory. Our agents abroad are only
under contractual obligation to service under
guarantee equipment sold through them. They
are entitled to make a non-refundable charge
for any service carried out on other equipment.
This guarantee does not limit your statutory
rightswithintheUnitedKingdom.
ABOUT THE PRODUCT
The Meridian C52 combines the finest
materials with state of the art design to create
what we believe is a superior subwoofer
controller,emphasisingextremebass,depth,
clarity, control, and articulation.
Each unit provides two controller and power
amplifier channels allowing the use of two
independent subwoofers. Both digital and
active analogue inputs are provided, allowing
the C52 to be connected either to a digital
surround controller or digital source with
adigitalcoaxoutput,ortoananalogue
preamplifier or surround controller with either
phono or balanced outputs.
Digital connectivity
The unit employs 96kHz/24bit digital-to-
analogue conversion and accept digital inputs
up to 96kHz including those carrying MHR
signals.
Separate analogue and digital power supplies
areusedtofeedtheC52’sprecisionelectronic
circuits, ensuring that both high and low
power sections receive continual smooth
supply.
If you are using the subwoofers with a digital
source, such as CD or DVD, the signals remain
in digital form until the last possible stage.
Subwoofer drivers
The C52 is designed to be used with Meridian
Installation Series subwoofer driver assemblies
such as the SW320. However, passive
subwoofers with similar specifications and
capabilities may alternatively be employed.
Power amplifiers
The C52 includes Class D high efficiency ultra
low output impedance amplifiers, optimised
for both music and movie soundtracks.
The whole electronic assembly is supplied from
substantial toroidal transformers feeding high-
quality, audiophile-grade capacitors.
C52 SPECIFICATIONS
Digitalinputs 2xcableinputs,32–96kHz
PCM using S/PDIF, or MHR
connection support with auto-
detection.
Analogueinputs 3xphonoinputs:mono,left,
right, per channel.
 2xXLRbalancedinputs:
Channel 1 and Channel 2.
Output stage Power amplifier: 300W
Class D high efficiency ultra
low output impedance (per
channel).
Characteristics Distortion <0.01%, typically
<0.02% up to full power at
all frequencies.
 Noiseandhum<–72dBm.
 Frequencyresponse20Hz–
400Hz.
Control 2xsetsMeridianComms
(BNC in and out; DIN in and
out).
Variable gain control (per
channel).
Variable low pass filter 40Hz-
150Hz.
Filter defeat switch (per
channel).
Absolute phase (polarity)
switch (per channel).
Power
100/115/120V; 220/230/240V
AC 50-60Hz.
20-500VA
Meridian Audio reserves the right to amend
product specifications at any time.

7
Accessories
Each unit is shipped complete with cables
to enable it to be used in a Meridian Digital
Music System.
Other applications, and some advanced
features, may require one or more of the
following accessories, which can be purchased
from your Meridian dealer:
• Additional S5 leads (8m and 14m).
• 511slavepatchboxifconnectingmorethan
two DSP loudspeakers to a Digital Surround
Controller.
INSTALLATION AND SETUP
Unpacking
• Inspectproductboxandunitforanyshipping
damage.
• Saveproductboxintheeventtheunitneedsto
be shipped in the future. Shipping the unit in a
genericboxmayvoidwarranty.
Mounting
The C52 is primarily designed to be mounted
in a standard 19in rack. However, screw-on
optional feet are provided for free-standing
operation. The feet should be removed if the
unit is to be rack-mounted.
• EXCESSIVEHEATMAYCAUSETHEUNITTO
MALFUNCTION OR SHORTEN PRODUCT LIFE.
Follow regular installation rules for proper
ventilation.
• Besureracklocationhasadequateventilation.
Allow a minimum of 1U rack space (1.75in)
above and below unit for ventilation.
• Allowadditionalventilationwhenmounted
near other power amplifiers or other equipment
thatmaygenerateexcessiveheat.
Connections
Be sure to use high quality cables for both
sources and output signals.
AC Power Connector
Connect to a stable AC power line. Ensure
that the unit is connected to a supply of the
voltage specified on the unit and that the unit
is of the correct type for the territory in which
it is being installed.
• Toavoidgroundloops,apowerconditionerfor
the equipment rack is recommended.
• Staticelectricitycancauseequipmentproblems.
Be sure installer is grounded to chassis or
equipment rack before connecting sources.

8
The C52 contains two identical subwoofer
controllers, Channel 1 and Channel 2. Unless
otherwise stated, this section refers to one
section only.
Output Connections
Connect the cables from the rear-panel output
terminals to the loudspeakers. Be sure to
observe correct polarity, and note that these
terminals can develop significant voltages/
current-passing capability when the C52 is
powered up and being fed with an active
signal. Ensure that connections are made
with the power disconnected from the
unit.
Digital connections
Identify the S/PDIF digital connections on the
rear panel as shown on the diagram above.
The Digital Input should be connected to
a digital source, such as a digital sound
processor, or digital preamplifier.
The Digital Output may be connected to a
second (slave) DSP loudspeaker, using an S5
lead.
The S/PDIF cable connected to the digital
input carries two channels. Set the DIGITAL
CHANNEL SELECTOR switches on the front
panel switch to indicate which channel(s) are
directed to each subwoofer.
• Ifyouareconnectingthesubwoofertothe
Centre/Sub or Side/Sub output of a Meridian
digital surround processor, set the switch to
position 2.
• Ifyoursystemincludesastereopairof
subwoofers, set the left subwoofer to position 1
and the right subwoofer to position 2.
• Ifyouareconnectingasinglesubwoofertoa
stereo digital system with no centre channel
output, such as a Meridian CD player, set the
switchtoposition1+2,tomixthesignalsfrom
both channels.
• Thedigitalconnectionsshouldbemadewith
high-quality 75Ωscreened cable. Suitable cables
are available from Meridian.
• Wedonotrecommendusinganalogueaudio
cables, which do not have adequate shielding
or the correct impedance, or cables intended
for UHF applications, as these do not provide
adequateshieldinginthe1–30MHzregion.
• Whenadigitalsignalisappliedtoachannel,
the front panel “Digital Signal Lock” indicator
will illuminate to show that the digital signal is
being correctly received.
Communications connections
Connect the Meridian Communications
sockets to the COMMS connection on a
Meridian control unit or preamplifier, using a
COMMS lead.
C52 Rear Panel (above) and front panel with acrylic cover removed (below)
CONNECTING THE C52

9
To connect a subwoofer in a Meridian
digital surround system
COMMS
OUTPUT INPUT
DIGITAL INPUT
2 1
DIGITAL
OUTPUT
COMMS
OUTPUT INPUT
DIGITAL INPUT
21
DIGITAL
OUTPUT
COMMS
OUTPUT INPUT
DIGITAL INPUT
21
DIGITAL
OUTPUT
DSP loudspeaker
Centre (master)
COMMS
S5 lead
M5 lead
SY lead S5 lead (digital unused)
Meridian Surround Processor
511 S-patch box
S5 lead
S5 lead
DSP loudspeaker – Main
C52 SUBWOOFER CONTROLLER
RDSP loudspeaker – Main L
COMMS
2
DIGITAL
INPUT
DIGITAL
OUTPUT
DIGITAL OUTPUTS
L/RC/S
If your system includes more than two
Meridian DSP loudspeakers you will need a
511slavepatchbox(availableseparately)to
link together the S5 leads from each speaker,
as shown above.
• Note:Thismaynotapplytothe861,whichmay
be ordered with a built-in patch box.
• UsethecommspartofanM5leadtoconnect
one of the COMMS sockets on the Meridian
Surround Processor to the DSP loudspeaker you
have chosen as the master (typically the centre
speaker).
• UsetheaudiopartoftheM5leadtoconnect
the DSP loudspeaker to the C/S digital output
on the Meridian Surround Processor.
• ConnectanSY-leadtotheCOMMSoutputfrom
the master DSP loudspeaker, then connect one
of the sockets on the SY lead to one socket on
the 511 using an S5 lead.
• LinkalltheotherDSPloudspeakerstogetherin
pairs using S5 leads, as shown in the illustration.
• ConnecteachpairofDSPloudspeakerstothe
appropriate digital output on the Meridian
Surround Processor, using an S5 lead. The
other part of the S5 lead is used to distribute
the COMMS from the 511 to each pair of DSP
loudspeakers.
• Setthedigitalchannelselectionswitchto
position 2 on the subwoofer.
To connect a subwoofer to a stereo
digital source, such as a Meridian CD
Player
COMMS
OUTPUT INPUT
DIGITAL INPUT
2 1
DIGITAL
OUTPUT
DIGITAL
OUTPUT
COMMS
DSP loudspeaker – Main R DSP loudspeaker – Main L
M5 lead
Meridian CD Player
COMMS
OUTPUT INPUT
DIGITAL INPUT
2 1
DIGITAL
OUTPUT
S5 lead
C52 SUBWOOFER CONTROLLER
COMMS DIGITAL
INPUT
DIGITAL
OUTPUT
S5 lead
1+2
You can connect a pair of DSP loudspeakers
and a subwoofer directly to a digital source.
The DSP loudspeakers include volume,
balance, and tone controls allowing you to
control the system using the MSR+.
• ConnecttheDIGITALOUTPUTandaCOMMS
socket from the Meridian source or control unit
to DIGITAL INPUT 1 and the COMMS input on
the DSP loudspeaker chosen as the master,
using an M5 lead.
• ConnecttheDIGITALandCOMMSoutputsfrom
the master DSP loudspeaker to DIGITAL INPUT 1
and the COMMS input on the other (slave) DSP
loudspeaker, using an S5 lead.
• ConnecttheDIGITALandCOMMSoutputs
from the slave DSP loudspeaker to the DIGITAL
INPUT and COMMS on the subwoofer, using an
S5 lead.
• Setthedigitalchannelselectorswitchto
position1+2,tomixtheleftandrightchannels
to the subwoofer.
Analogue input connections
Connect the PHONO INPUT MONO to the
dedicated subwoofer output of a preamplifier
or surround controller, if it is the only
subwoofer in the system, or the left or right
output of a preamplifier or digital surround
processor, if the subwoofer is used as one of a
stereo pair.
PHONO INPUT LEFT/RIGHT should be
connected to the left and right outputs of a
preamplifier or surround processor, if it is the
only subwoofer.

10
XLRBALANCEDINPUT(Channel1/2)should
be connected to the dedicated balanced
subwoofer output of a preamplifier or
surround controller, if it is the only subwoofer
inthesystem,ortheleftorrightXLRoutput
of a preamplifier or digital surround processor
with balanced outputs, if the subwoofer is one
of a stereo pair.
If you are connecting a single subwoofer to
a preamplifier or surround processor with a
dedicated subwoofer output, connect that
balanced output to the appropriate balanced
mono input channel on the C52.
If you are connecting two subwoofers to a
system, connect the left channel output to the
balanced input of the one C52 channel and
the right channel output to the balanced input
of the other C52 channel.
The audio connections should be made with
highqualityaudiophonoleadsorXLRleads.
To connect a subwoofer to an
analogue preamplifier
PHONO
INPUTS
XLR BALANCED
INPUTS
PHONO
OUTPUTS
L
R
Analogue Preamplifier
C52 SUBWOOFER CONTROLLER
• Connecttheanalogueoutputsfromthe
preamplifier or analogue surround processor
to the LEFT and RIGHT phono inputs of the
subwoofer.Thesubwoofermixesthechannels
to create a mono signal.
• Ifyourpreamplierprovidesbalancedoutputs,
usetheLEFTandRIGHTXLRBALANCEDinputs
on the subwoofer instead.
To connect a stereo pair of subwoofers
to an analogue preamplifier
C52 CONTROLLER
PHONO
INPUTS
XLR BALANCED
INPUTS
PHONO
OUTPUTS
L
R
Analogue Preamplifier
C52 CONTROLLER
PHONO
INPUTS
XLR BALANCED
INPUTS
• Connecttheleftanalogueoutputfromthe
preamplifier to the MONO PHONO INPUT of the
left subwoofer.
• Connecttherightanalogueoutputfromthe
preamplifier to the MONO PHONO INPUT of the
right subwoofer.
• Ifyourpreamplierprovidesbalancedoutputs,
usetheMONOXLRBALANCEDinputoneach
subwoofer instead.
CONFIGURING THE SUBWOOFER
To adjust the C52, remove the smoked acrylic
front panel to access the controls. Replace it
when configuration has been satisfactorily
completed to avoid unintentional adjustment.
Setting the adjustable low-pass filter
Each channel includes a low-pass filter which
can be adjusted between 40Hz and 150Hz, or
disabled using the DEFEAT switch.
If you are connecting the subwoofer to a
digital surround processor that provides its
own crossover, such as a Meridian digital
surround processor, set the low-pass filter
switch to DEFEAT.
If you are connecting the subwoofer to an
analogue preamplifier or surround processor,
set the low-pass filter to the middle of its
range, and then listen to a sweep tone from
the processor if it provides one, or alternatively
from a test disc, and make sure the bass is
smooth throughout the range.
If there is a peak in the bass loudness, the
subwoofer may be adding to the bass from
your main speakers, in which case reduce the
low-pass filter frequency.
Likewise, if there is a dip in the bass loudness,
increase the low-pass filter frequency.
Setting the gain
The GAIN control allows you to adjust the
loudness of the subwoofer to suit the other
components in your system.
For the best signal to noise ratio, adjust the
level of the subwoofer using the level control
on the subwoofer. If you are using a Meridian
Digital Surround Processor, you can then use
theprocessor’scalibrationoptiontone-tune
the subwoofer level if necessary.

11
If your surround processor or preamplifier
does not include a Calibration option, listen to
familiar source materials and adjust the gain
until the bass sounds solid and deep, but not
boomy or intrusive.
Setting the phase (polarity)
The PHASE switch allows you to invert the
phase (reverse the polarity) of the signal to the
subwoofer.
If your digital surround processor includes
a Calibration option and you can adjust the
phase there, set the switch to the + position.
If the bass sounds hollow or phasey, and does
not image correctly, change the position of the
PHASE switch. If in doubt, select the position
that gives the most bass.
When you have completed configuration of
the C52, replace the acrylic cover provided, to
avoid unintentional adjustment.
TROUBLESHOOTING
Unit goes silent when played hard
The unit has a temperature sensing system
on board, which prevents overheating of the
electronics. The sound will continue when the
speaker has cooled.
There is radio interference
The subwoofer is a digital audio and
computing device which has been designed
to very high standards of electromagnetic
compatibility.
If this equipment does cause or suffer from
interference to/from radio or television
reception then the following measures should
be tried:
• Reorientthereceivingaerial(orantenna)or
route the antenna cable of the receiver as far as
possible from the subwoofer and its cabling.
• Ensurethatthereceiveruseswell-screened
antenna cable.
• Relocatethereceiverwithrespecttothe
subwoofer.
• Connectthereceiverandthisproductto
different AC outlets.
• Iftheproblempersistscontactyourdealer.
Drive units move when the C52 is
switched on or off
This is normal as the electronics settle.
Subwoofer stays in standby
This indicates a problem with the Comms
setup:
• Checkthecommscabling
• Reselectthesourceandincreaseordecreasethe
volume.
Subwoofer output sounds odd and
lacking in bass when connected to a
Meridian digital processor
A digital audio connection carries two
channels. Make sure that you are picking
uptherightone.Forexample,ifyouhave
connected the subwoofer to the Centre/Sub
output of the processor, make sure that the
digital input switch is set to 2 to pick up the
sub signal. If it is set to 1 you will hear the
signal intended for the centre channel.
If the speaker on a channel is configured as
Small its signal will not contain any bass, and
a subwoofer set to pick up that channel will
therefore not output much of a signal. Check
the subwoofer definitions in the configuration
and change as necessary.

C52manv1.1•REƒ•20070810
Meridian Audio Limited
Latham Road,
Huntingdon, Cambridgeshire PE29 6YE
UnitedKingdom
Tel [phone]
Fax+44(0)1480445686
Web: www.meridian-audio.com
Meridian is registered trademark of Meridian Audio Ltd
Other trademarks are the property of their respective owners.
Meridian America Inc
8055 Troon Circle, Suite C
Austell, Atlanta GA 30168-7849
USA
Tel [phone]
Fax+1(404)3467111
Email: [email protected]