Drawmer SP2120 User manual

DRAWMER
SP2120
Speaker Protector
CONTENTS
Warranty
Safety Consideration
Chapter 1 - Introduction
Introduction
Installation
Tamper-proofBracket
AudioConnections
Installationand Connection Guide -Stereo Pair
InstallationandConnectionGuide-MultipleSpeakers
Chapter 2 - Control Description
FrontPanelControls
TheSetupProcedure
Chapter 3 - General Information
Ifafaultdevelops
Contacting Drawmer
Specification
Block Diagram
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Drawmer Electronics Ltd., warrants the Drawmer SP2120
SpeakerProtectortoconformsubstantiallytothespecifications
ofthismanualfor a periodofoneyear from theoriginaldateof
purchase when used in accordance with the specifications
detailed in this manual. In the case of a valid warranty claim,
yoursole andexclusive remedy andDrawmer’s entireliability
underany theoryof liabilitywill beto, atDrawmer’s discretion,
repairorreplace theproductwithout charge, or,ifnot possible,
to refund the purchase price to you. This warranty is not
transferable. It applies only to the original purchaser of the
product.
For warranty service please call your local Drawmer dealer.
Alternatively call Drawmer Electronics Ltd. at +44 (0)1709
527574. Then ship the defective product, with transportation
andinsurance chargespre-paid, to DrawmerElectronics Ltd.,
ColemanStreet,Parkgate,Rotherham,S62 6EL UK.Writethe
RA number in large letters in a prominent position on the
shippingbox.Enclose your name,address,telephonenumber,
copyoftheoriginal sales invoiceanda detailed descriptionof
theproblem.Drawmer will notacceptresponsibility forlossor
damage during transit.
This warranty is void if the product has been damaged by
misuse, modification or unauthorised repair.
THIS WARRANTY IS IN LIEU OF ALL WARRANTIES,
WHETHERORALORWRITTEN,EXPRESSED,IMPLIEDOR
STATUTORY.DRAWMER MAKES NOOTHER WARRANTY
EITHER EXPRESS OR IMPLIED, INCLUDING, WITHOUT
LIMITATION, ANY IMPLIED WARRANTIES OF
MERCHANTABILITY,FITNESSFORAPARTICULARPURPOSE,
OR NON-INFRINGEMENT. PURCHASER’S SOLE AND
EXCLUSIVEREMEDYUNDERTHIS WARRANTY SHALLBE
REPAIRORREPLACEMENTASSPECIFIEDHEREIN.
IN NO EVENT WILL DRAWMER ELECTRONICS LTD. BE
LIABLEFORANYDIRECT,INDIRECT,SPECIAL,INCIDENTAL
ORCONSEQUENTIALDAMAGESRESULTINGFROMANY
DEFECT IN THE PRODUCT, INCLUDING LOST PROFITS,
DAMAGETOPROPERTY,AND,TOTHEEXTENTPERMITTED
BY LAW, DAMAGE FOR PERSONAL INJURY, EVEN IF
DRAWMERHAS BEENADVISED OF THEPOSSIBILITY OF
SUCHDAMAGES.
Somestates and specificcountries do notallow the exclusion
of implied warranties or limitations on how long an implied
warranty may last, so the above limitations may not apply to
you. This warranty gives you specific legal rights. You may
haveadditionalrightsthatvary from state tostate,andcountry
tocountry.
In the interests of product development, Drawmer reserve the right to modify or
improve specifications of this product at any time, without prior notice.
ONE YEAR LIMITED WARRANTY
COPYRIGHT
This manual is copyrighted 82012 by Drawmer Electronics Ltd. With all rights reserved. Under copyright
laws, no part of this publication may be reproduced, transmitted, stored in a retrieval system or translated
intoany language in any formby any means, mechanical, optical, electronic, recording, or otherwise, with-
out the written permission of Drawmer Electronics Ltd.
DRAWMER
SP2120
SPEAKER PROTECTOR
SAFETY CONSIDERATIONS
CAUTION-MAINSFUSE
TO REDUCE THE RISK OF FIRE
REPLACETHEMAINS FUSEONLY WITH
A FUSE THAT CONFORMS TO IEC127-2.
250 VOLT WORKING, TIME DELAY TYPE
AND BODY SIZE OF 20mm x 5mm.
THEMAINS INPUTFUSE MUSTBE
RATEDAT230V=T50mAand115V=T100mA.
CAUTION-MAINSCABLE
DO NOT ATTEMPT TO CHANGE
OR TAMPER WITH THE
SUPPLIEDMAINSCABLE.
CAUTION-SERVICING
DO NOT PERFORM ANY SERVICING.
REFERALL SERVICING TO QUALIFIED
SERVICE PERSONNEL.
WARNING
TO REDUCE THE RISK OF FIRE OR
ELECTRIC SHOCK DO NOT EXPOSE
THISEQUIPMENT TO RAINOR MOISTURE.
It is the responsibility of the installer to ensure that the continuous power rating of the speakers is not exceeded, as
Drawmer Electronics Ltd will not accept any responsibility for damage caused by incorrect installation and settings.

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DRAWMER
SP2120
SPEAKER PROTECTOR
TheDrawmer SP2120SpeakerProtector offersbothstrict
level control and tremendous peace of mind to the con-
tractor, installer and venue in the knowledge that, as its
namesuggests, the 1U,twochannel processor eliminates
thepossibilityof’unauthorised’ excessive sound pressure
levelson speaker systems (as caused by spikes andpops
inthesystem,orbyover-enthusiastdj’s/engineers)which
CHAPTER 1
INTRODUCTION
could result in damage to both chassis drivers and ampli-
fier electronics. In addition only the maintenance engi-
neer and the venue manager hold a key. The unit also
gives a wide variety of venues, such as clubs, theatres,
pubs, schools, universities etc. the opportunity to comply
withthe local legislation regarding noise levels.
The key features are as follows:
• Key Holder access only
• Takes only minutes to install
•Tamper-Proofbracket(availableseparately) to lock-in the XLR’s and conform to Local Authority regulations.
• Dual 16 segment Left/Right bargraphs for ’at a glance’ level metering
• ’Protection’ processing 16 segment bargraph display
• No sound quality loss even during heavy protection processing
• Once installed and calibrated completely eliminates the possibility of ’unauthorised’ volume levels
• Eliminates sound system abuse and the resulting cost of chassis speaker re-cones, HF diaphragm
replacements and amplifier repairs.
• Reduces ’call-out’ costs of sound system service/repair engineers
• Reduces sound system ’down time’ and the consequential loss of venue income
•Isolationtransformeroutputoption.
TheSP2120 front panel features an integral security lock
toensure thatadjustmentstomaximumvolume levelsare
implemented by key holders only. In ’unlocked’ mode two
front panel pre-sets are exposed and available for
adjustment by the installer. The first calibrates the 16
segment Left/Right bargraphs to the incoming audio and
dictates the point at which ’protection’ processing
commences. The second sets the absolute volume level
to which the sound system is allowed to perform. If the
SP2120receives increased signal levels, the transparent
’protection’ circuitry is activated which maintains the
specifiedsystemvolumelevelwithout degradationinsound
quality.
The SP2120 greatly benefits from Drawmer’s 25 years
experience in designing industry standard dynamic
processing devices. Its signal path combines a mixture of
’multipletime constant’circuitryand automaticgaincontrol
(AGC)which allow smalloverloadstosound louder –even
though they’re not.
Itsconcept anddevelopmentwas encouragedbyDrawmer
distributorsand installers dissatisfied with other protection
systems currently available. These often take the form of
acrudeswitch,eitherturningoffthepower ordisconnecting
the speakers, both of which are ’disruptive’ in any event.

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(orbeforetheactivespeakers),withtheamplifiervolume
settomaximum.Ifthe SP2120weretobeconnectedearlier
inthechain,priortothe pre-amp/mixer for example, then
itwouldbepossibleto addgain,sendingnoiselevelshigher
thanrequired.
TheSP2120 can be usedinaconfiguration where a stereo
outputisdistributed around several speakers. Fig.3shows
a setup where the signal is distributed into six pairs using
a Drawmer DA6, whilst still providing speaker protection
for all twelve speakers. Again, note the position of the
SP2120’s along the audio chain - they should all be
connected directly before the amplifier that is supplying
thespeakers(oractivespeakers), withtheamplifiervolume
set to maximum.
INSTALLATION
AUDIO CONNECTIONS
The inputs and outputs are electronically balanced XLRs where pin 1 is screen, pin 2 hot, pin 3 cold and the XLR shell
• Interference:
If the unit is to be used where it maybe
exposedto highlevels ofdisturbance such
asfoundclosetoaTV orradio transmitter,
we advise that the unit is operated in a
balancedconfiguration. The screensofthe
signal cables should be connected to the
chassisconnectionon the XLR connector
as opposed to connecting to pin1. The
SP2120 conforms to the EMC standards.
• Ground Loops:
Ifgroundloop problems are encountered,
never disconnect the mains earth, but
instead, try disconnecting the signal
screen on one end of each of the cables
connecting the outputs of the SP2120 to
the patchbay. If such measures are
necessary, balanced operation is
recommended.
fig.1 XLR WIRING
The SP2120 Speaker Protector is designed for standard
19"rack mounting and occupies 1U of rack space.Where
possible, avoid mounting the unit directly above power
amplifiersorpowersuppliesthat radiatesignificantamounts
ofheat.
If the unit is to be used in a mobile situation, it is strongly
recommended that the rear of the unit is supported in the
carryingracktoavoidbendingthefrontpanelrackmounting
‘ears’.Usefibreorplastic washerstopreventthefrontpanel
becomingmarkedbythemountingbolts.Alwaysconnect
the mains earth to the unit.
Fig. 2 shows the ideal connection setup, providing the
greatest protection for your system. Note the position of
theSP2120 along theaudiochain - itshouldbe connected
directlybeforetheamplifierthatissupplyingthespeakers,
Drawmerhavegoneto great lengths to make the Speaker
Protector tamper-proof by incorporating the locking
mechanism on the front. However, if the rear of the unit,
alongwiththe power amplifier, were reconnected then the
protectionsystemwouldeffectivelybebypassed.Forthis
reason Drawmer have designed the Speaker Protector
Tamper-proof Bracket - trapping the XLR’s in place and
making it extremely difficult to disconnect them without
removing the bracket. This bracket could be specified in
order to conform to Local Authority noise abatement
regulations.
Installation of the Tamper-proof bracket could not be
simpler: After setting up the SP2120 Speaker Protector
as described in the manual, with the XLR’s in place,
simplyslidetheTamper-proof Bracketoverthe rear of the
unit,making sure that theprotrudingcableslocate through
is connected to chassis. The operating
levelis nominally+4dBu.Balanced use is
recommended.
the gaps on the bracket. Next, screw in to place at the
four locating points (arrowed below) using the M3 screws
provided. Further protection can be gained by fitting M3
TORXtamperproof screws, toamaximum lengthof6mm,
though a specialist screwdriver will also be required.
In addition, for extra protection, both the SP2120 and the
power amp should be locked in a rack, where access to
therear is very difficult.
You should note that the Tamper-proof bracket is only
availableforSP2120’swho’sserialnumberis0845or higher
(September 2006). On older versions the bracket could
be retro- fitted, though this would invalidate any warranty
thatDrawmerhas provided for the SP2120.Alternatively,
Drawmercould bring your SP2120 up to current Drawmer
specification-pleasecontactyour localdistributororemail:
[email protected]for furtherdetails.
TAMPER-PROOF BRACKET

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fig.2 INSTALLATION AND CONNECTION GUIDE - Stereo Pair

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fig.3 INSTALLATION AND CONNECTION GUIDE - Multiple Speakers

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f.Adjustthe“SetMaximum Output Level” control until
the noise levels from the power amp reaches a level
as set by the local authority, or the maximum level
that can be tolerated (whichever is lowest) - in this
way even if the input levels are increased, by an
engineer applying gain on the mixing desk for
example, this noise level will never be exceeded.
g.Lock the unit and remove the key .
h.If required, for increased security, or if regulations
recommend it, fit a Drawmer Tamper-Proof Bracket
to the rear. (Avaliable seperately).
i.Lock the cabinet that the SP2120 and amplifier are
in.
Test the system by increasing gain from the mixing desk (or
anywhere preceeding the SP2120 in the audio chain) - as
you increase the level the protection meter should
increase but the overall signal level of the system will remain
within the set parameters.
a.Ensure that the system is connected correctly and
that both the SP2120 and the amplifier that follows
it are locked in a cabinet where access is limited.
b.Using the key provided unlock the front to provide
access the the calibration controls.
c.Using a small screwdriver turn the calibrate controls
“Set VU Meter to 0dB” and “Set Maximum Output
Level” fully anti-clockwise to the min position.
d.Turn the level on the power amp to its maximum
gain level.
e.Playing a load piece of music, that will provide high
input levels to the SP2120, rotate the “Set VU Meter
to 0dB” control until the L/R VU meters
reach 0dB on signal peaks, and no more than the
first two leds of the protection meter are lit.
CONTROL DESCRIPTION
THE SETUP PROCEDURE
SECURITYLOCK-OUT A lock prevents access to the front panel controls of the SP2120 once it has been calibrated.
Unlock, calibrate, lock again. Only authorised personnel should be supplied with a key.
CALIBRATE
SET VU METER With the unit unlocked, rotate using a screwdriver to adjust the level of signal to the vu meters.
TO0dB The general rule is to adjust the level so that the meters reach 0dB only on signal peaks.
SET MAXIMUM With the unit unlocked, rotate using a screwdriver to adjust the level of signal supplied to
OUTPUTLEVEL the amplifier.
VU METER Two 16 LED, left and right bargraph meters provides a visual indication of the levels to adjust
the “Set VU meter to 0dB” control.
PROTECTION A 16 LED bargraph meter provides a visual indication of the amount of protection that is being
METER carried out by the SP2120. The higher the protection meter reads the more the SP2120 is
having to work to keep the levels of sound within the set parameters - set the controls so that
this meter illuminates as little as possible.
CHAPTER 2
1 2 3 4 5
1
2
3
4
5
1
2
3
4
5
2
3
1
Use the following procedure to setup your system. In a configuration where a stereo output is distributed around several
speakers, such as in fig.3, then the setup procedure should be used for each speaker pair.
5

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IF A FAULT DEVELOPS
For warranty service please call Drawmer Electronics Ltd. or
their nearest authorised service facility, giving full details of
the difficulty.
A list of all main dealers can be found on the Drawmer
webpages.
On receipt of this information, service or shipping instructions
will be forwarded to you.
No equipment should be returned under the warranty without
prior consent from Drawmer or their authorised representative.
For service claims under the warranty agreement a service
Returns Authorisation (RA) number will be issued.
Write this RA number in large letters in a prominent position
on the shipping box. Enclose your name, address, telephone
number, copy of the original sales invoice and a detailed
description of the problem.
Authorised returns should be prepaid and must be insured.
All Drawmer products are packaged in specially designed
containers for protection. If the unit is to be returned, the original
container must be used. If this container is not available, then
the equipment should be packaged in substantial shock-proof
material, capable of withstanding the handling for the transit.
CONTACTING DRAWMER
Drawmer Electronics Ltd., will be pleased to answer all
application questions to enhance your usage of this
equipment. Please address correspondence to:
Drawmer (Technical Help line)
Coleman Street
Parkgate
Rotherham
S62 6EL
UK
Alternatively contact us by E-mail on :
[email protected]
Further information on all Drawmer dealers, Authorised service
departments and other contact information can be obtained
from our web pages on:
http://www.drawmer.com
GENERAL INFORMATION
CHAPTER 3
INPUT
Input Impedance 20k Ohms
Max Input level +21dBu
CMR >40dB (22Hz-22kHz)
OUTPUT
Output Impedance 100 Ohms
Output Level Variable. Infinity to +14dBu
Balance >40dB (22Hz-22kHz)
Isolating Transformers can be fitted in Output stage.
Crosstalk > 90dB at 20k Hz
Noise -103dB (Unity gain ref +4dBu /
22Hz-22kHz)
SP2120 SPEAKER PROTECTOR
DATA SPECIFICATION
It is the responsibility of the installer to ensure that the continuous power rating of the speakers is not
exceeded, as Drawmer Electronics Ltd will not accept any responsibility for damage caused by incorrect
installation and settings.
Power Requirements 115Voltor 230Voltat50-60Hz,9VA
Fuse CONFORMSTOIEC127-2.
230V=T50mA, 115V=T100mA.
Dimensions 482mm(W) x 44mm (H) x
160mm(D)
Weight 2.2kg

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BLOCKDIAGRAM
SP2120ver03A15/11/12