Harman DBX 20 Series User manual

OperatiOn Manual
MOde d’eMplOi
Bedienungsanleitung
MOdO de eMpleO
20 SERIES
EQUALIZER/LIMITER
with TYPE III NR

IMPORTANT SAFETY INFORMATION
WARNING FOR YOUR PROTECTION
READ THE FOLLOWING:
KEEP THESE INSTRUCTIONS
HEED ALL WARNINGS
FOLLOW ALL INSTRUCTIONS
THE APPARATUS SHALL NOT BE EXPOSED TO DRIPPING OR SPLASHING
LIQUID AND NO OBJECT FILLED WITH LIQUID, SUCH AS VASES, SHALL BE
PLACED ON THE APPARATUS.
CLEAN ONLY WITH A DRY CLOTH.
DO NOT BLOCK ANY OF THE VENTILATION OPENINGS. INSTALL IN AC-
CORDANCE WITH THE MANUFACTURER’S INSTRUCTIONS.
DO NOT INSTALL NEAR ANY HEAT SOURCES SUCH AS RADIATORS,
HEAT REGISTERS, STOVES, OR OTHER APPARATUS (INCLUDING AMPLI-
FIERS) THAT PRODUCE HEAT.
ONLY USE ATTACHMENTS/ACCESSORIES SPECIFIED BY THE MANUFAC-
TURER.
UNPLUG THIS APPARATUS DURING LIGHTNING STORMS OR WHEN
UNUSED FOR LONG PERIODS OF TIME.
Do not defeat the safety purpose of the polarized or grounding-type plug. A
polarized plug has two blades with one wider than the other. A grounding
type plug has two blades and a third grounding prong. The wide blade or third
prong are provided for your safety. If the provided plug does not fit your outlet,
consult an electrician for replacement of the obsolete outlet.
Protect the power cord from being walked on or pinched particularly at plugs,
convenience receptacles, and the point where they exit from the apparatus.
Use only with the cart stand, tripod bracket, or table specified by the manufac-
ture, or sold with the apparatus. When a cart is used, use caution when moving
the cart/apparatus combination to avoid injury from tip-over.
Refer all servicing to qualified service personnel. Servicing is required when
the apparatus has been damaged in any way, such as power-supply cord or plug
is damaged, liquid has been spilled or objects have fallen into the apparatus, the
apparatus has been exposed to rain or moisture, does not operate normally, or
has been dropped.
POWER ON/OFF SWITCH: If the equipment has a Power switch, the Power
switch used in this piece of equipment DOES NOT break the connection from
the mains.
MAINS DISCONNECT: The plug shall remain readily operable. For rack-mount
or installation where plug is not accessible, an all-pole mains switch with a
contact separation of at least 3 mm in each pole shall be incorporated into the
electrical installation of the rack or building.
FOR UNITS EQUIPPED WITH EXTERNALLY ACCESSIBLE FUSE RECEPTA-
CLE: Replace fuse with same type and rating only.
MULTIPLE-INPUT VOLTAGE:This equipment may require the use of a different
line cord, attachment plug, or both, depending on the available power source at
installation. Connect this equipment only to the power source indicated on the
equipment rear panel.To reduce the risk of fire or electric shock, refer servicing
to qualified service personnel or equivalent.
If connected to 240V supply, a suitable CSA/UL certified power cord shall be
used for this supply.
This Equipment Is Intended For Rack Mount Use Only.
Safety InStructIonS
NOTICE FOR CUSTOMERS IF YOUR UNIT IS EQUIPPED WITH A POWER CORD.
WARNING: THIS APPLIANCE SHALL BE CONNECTED TO A MAINS SOCKET OUTLET WITH A
PROTECTIVE EARTHING CONNECTION.
The cores in the mains lead are coloured in accordance with the following code:
GREEN and YELLOW - Earth BLUE - Neutral BROWN - Live
As colours of the cores in the mains lead of this appliance may not correspond with the coloured
markings identifying the terminals in your plug, proceed as follows:
•The core which is coloured green and yellow must be connected to the terminal in the plug
marked with the letter E, or with the earth symbol, or coloured green, or green and yellow.
•The core which is coloured blue must be connected to the terminal marked N or coloured
black.
•The core which is coloured brown must be connected to the terminal marked L or coloured
red.
This equipment may require the use of a different line cord, attachment plug, or both, depending
on the available power source at installation. If the attachment plug needs to be changed, refer
servicing to qualified service personnel who should refer to the table below. The green/yellow
wire shall be connected directly to the units chassis.
CONDUCTOR WIRE COLOR
Normal Alt
LLIVE BROWN BLACK
NNEUTRAL BLUE WHITE
EEARTH GND GREEN/
YEL GREEN
WARNING: If the ground is defeated, certain fault conditions in the unit or in the system to
which it is connected can result in full line voltage between chassis and earth ground. Severe
injury or death can then result if the chassis and earth ground are touched simultaneously.
The symbols shown above are internationally accepted symbols that warn of
potential hazards with electrical products. The lightning flash with arrowpoint in
an equilateral triangle means that there are dangerous voltages present within
the unit. The exclamation point in an equilateral triangle indicates that it is nec-
essary for the user to refer to the owner’s manual.
These symbols warn that there are no user serviceable parts inside the unit. Do
not open the unit. Do not attempt to service the unit yourself. Refer all servic-
ing to qualified personnel. Opening the chassis for any reason will void the
manufacturer’s warranty. Do not get the unit wet. If liquid is spilled on the unit,
shut it off immediately and take it to a dealer for service. Disconnect the unit
during storms to prevent damage.
CAUTION
ATTENTION: RISQUE DE CHOC ELECTRIQUE - NE PAS OUVRIR
WARNING: TO REDUCE THE RISK OF FIRE OR ELECTRIC
SHOCK DO NOT EXPOSE THIS EQUIPMENT TO RAIN OR MOISTURE
RISK OF ELECTRIC SHOCK
DO NOT OPEN

LITHIUM BATTERY
WARNING
CAUTION!
This product may contain a lithium battery.There is danger of
explosion if the battery is incorrectly replaced. Replace only with
an Eveready CR 2032 or equivalent. Make sure the battery is
installed with the correct polarity. Discard used batteries according
to manufacturer’s instructions.
ADVARSEL!
Lithiumbatteri - Eksplosjonsfare.Ved utskifting benyttes kun batteri
som anbefalt av apparatfabrikanten. Brukt batteri returneres appa-
ratleverandøren.
ADVARSEL!
Lithiumbatteri - Eksplosionsfare ved fejlagtig håndtering.
Udskiftning må kun ske med batteri av samme fabrikat og type.
Levér det brugte batteri tilbage til leverandøren.
VAROITUS!
Paristo voi räjähtää, jos se on virheellisesti asennettu.Vaihda paristo
ainoastaan laitevalmistajan suosittelemaan tyyppin. Hävitä käytetty
paristo valmistajan ohjeiden mukaisesti.
VARNING!
Explosionsfara vid felaktigt batteribyte.Använd samma batterityp
eller en ekvivalent typ som rekommenderas av apparattillverkaren.
Kassera använt batteri enligt fabrikantens instruktion.
IMPORTANT SAFETY INFORMATION
U.K. MAINS PLUG WARNING
A molded mains plug that has been cut off from the cord is unsafe.
Discard the mains plug at a suitable disposal facility. NEVER
UNDER ANY CIRCUMSTANCES SHOULD YOU INSERT A
DAMAGED OR CUT MAINS PLUG INTO A 13 AMP
POWER SOCKET. Do not use the mains plug without the fuse
cover in place. Replacement fuse covers can be obtained from your
local retailer. Replacement fuses are 13 amps and MUST be ASTA
approved to BS1362.
ELECTROMAGNETIC COMPATIBILITY
This unit conforms to the Product Specifications noted
on the Declaration of Conformity. Operation is sub-
ject to the following two conditions:
 •thisdevicemaynotcauseharmfulinterference,and
 •this device must accept any interference received,
including interference that may cause undesired
operation.
Operation of this unit within significant electromagnetic
fields should be avoided.
 •useonlyshieldedinterconnectingcables.
Manufacturer’s Name: dbx Professional Products
Manufacturer’s Address: 8760 S. Sandy Parkway
Sandy, Utah 84070, USA
declares that the product:
Product name: dbx 2031, dbx2215 and dbx2231
Note: Product name may be suffixed by the letters-EU.
Product option: None
conforms to the following Product Specifications:
Safety: IEC 60065 -01+Amd 1
EMC: EN 55022:2006 (N/A; Analog Product)
IEC61000-4-2
IEC61000-4-3
IEC61000-4-4
IEC61000-4-5
IEC61000-4-6
IEC61000-4-8
IEC61000-4-11
Supplementary Information:
The product herewith complies with the requirements of the:
Low Voltage Directive 2006/95/EC
EMC Directive 2004/108/EC.
RoHS Directive 2002/95/EC
WEEE Directive 2002/96/EC
With regard to Directive 2005/32/EC and EC Regulation
1275/2008 of 17 December 2008, this product is designed,
produced, and classified as Professional Audio Equipment and
thus is exempt from this Directive.
Roger Johnsen
Director, Engineering
Signal Processing
8760 S. Sandy Parkway
Sandy, Utah 84070, USA
Date: November 19, 2010
European Contact: Your local dbx Sales and Service Office or
Harman Music Group
8760 South Sandy Parkway
Sandy, Utah 84070 USA
Ph: [phone]
Fax: [phone]
DECLARATION OF CONFORMITY
If you want to dispose this product, do not mix it with general household waste. There is a
separate collection system for used electronic products in accordance with legislation that
requires proper treatment, recovery and recycling.
Private household in the 25 member states of the EU, in Switzerland and Norway may return their used
electronic products free of charge to designated collection facilities or to a retailer (if you purchase a similar
new one).
For Countries not mentioned above, please contact your local authorities for a correct method of disposal.
By doing so you will ensure that your disposed product undergoes the necessary treatment, recovery and
recycling and thus prevent potential negative effects on the environment and human health.
Warranty
This warranty is valid only for the original purchaser and only in the United States.
1. The warranty registration card that accompanies this product must be mailed within 30
days after purchase date to validate this warranty. You can also register online at
www.dbxpro.com. Proof-of-purchase is considered to be the responsibility of the consumer.
A copy of the original purchase receipt must be provided for any warranty service.
2. dbx warrants this product, when bought and used solely within the U.S., to be free from
defects in materials and workmanship under normal use and service.
3. dbx liability under this warranty is limited to repairing or, at our discretion, replacing
defective materials that show evidence of defect, provided the product is returned to dbx
WITH RETURN AUTHORIZATION from the factory, where all parts and labor will be covered up
to a period of two years. A Return Authorization number must first be obtained from dbx. The
company shall not be liable for any consequential damage as a result of the product’s use in
any circuit or assembly.
4. dbx reserves the right to make changes in design or make additions to or improvements
upon this product without incurring any obligation to install the same additions or improve-
ments on products previously manufactured.
5. The foregoing is in lieu of all other warranties, expressed or implied, and dbx neither
assumes nor authorizes any person to assume on its behalf any obligation or liability in con-
nection with the sale of this product. In no event shall dbx or its dealers be liable for special
or consequential damages or from any delay in the performance of this warranty due to
causes beyond their control.

OPERATION MANUAL
1
20 SERIES GRAPHIC EQUALIZERS
Manual Contents
English ..................................................... 2
Français ..................................................... 7
DEutsch ..................................................... 15
Español ..................................................... 23
english Contents
introDuction.................................................. 2
inspEction .................................................... 2
opErating controls ........................................... 2
connEcting thE EQ to your systEm .............................. 4
rEar panEl DEscriptions........................................ 4
installation consiDErations .................................... 5
opEration anD applications notEs............................... 6
tEchnical support / Factory sErvicE ............................. 6
spEciFications ................................................. 32
Block Diagram................................................ 33

2
OPERATION MANUAL
introduCtion
Congratulations on your purchase of a dbx graphic equalizer. All dbx graphic equalizers are high performance multi-
functional units designed to deliver all the flexibility and power that professional users demand. We recommend that
you take a moment to read through this operation manual. It provides information that will assist you from system set-
up to EQ applications. The 20 Series Equalizers include the following features:
 •RevolutionarydbxTYPEIII™NoiseReductioncapableofrestoringupto20dBS/Nratio
 •Proprietarypatent-pendingPeakPlus™Limiterforsystemprotection
 •Switchablerangebetween±6dBand±15dB
 •Balancedinputsandoutputs
 •XLR,BarrierStrip,and1/4”TRSconnectors
 •-12dB/+12dBinputgainrange
 •18dB/octave40HzBesselLow-Cutfilter
 •Chassis/signalgroundliftcapability
 •Internalpowersupplytransformer
 •Power-offhard-wirerelaybypasswith2-secondpower-updelay
inspeCtion
Verify that the equalizer’s package contains the following:
 •Equalizerunitmatchingserialnumbermarkedonpackage
 •ACpowercord
 •OperationManual
 •RegistrationCard
 •Fourrackmountscrewsandwashers
If any of these items are missing please contact dbx customer service at the number provided on the back cover of this
manual.
operating Controls
Front Panels
2031-singlechannel31bandgraphicequalizer
2231-dualchannel31bandgraphicequalizer
RANGE
GAIN
REDUCTION (dB)
OUTPUT
LEVEL (dBu)
LOW
CUT
EQ
BYPASS
TYPE III
NR
INPUT
GAIN
dB
-12
0
+12
PeakPlus
THRESHOLD
dBu
0 OFF
+20+5
+15+10
+/-6
+/-15
CLIP
1
0
-6
+6
20 25 31.5 40 50 63 80 500400315250 1.6k1.25k1k800 5k4k3.15k2.5k 16k12.5k10k8k6.3k 20k2k630100 125 160 200
0
-15
+15
3610+18+100-10
2031
Equalizer/Limiter
with TYPE III NR
85-2564-A0 2031 FRONT ART 12-16-96
2231
Equalizer/Limiter
with TYPE III NR
20 25 31.5 40 50 63 80 500400315250 1.6k1.25k1k800 5k4k3.15k2.5k 16k12.5k10k8k6.3k 20k2k630100 125 160 200
RANGE
GAIN
REDUCTION (dB)
OUTPUT
LEVEL (dBu)
LOW
CUT
EQ
BYPASS
TYPE III
NR
INPUT
GAIN
dB
-12
0
+12
PeakPlus
THRESHOLD
dBu
0 OFF
+20+5
+15+10
+/-6
+/-15
CLIP
13610+18+100-10
RANGE
GAIN
REDUCTION (dB)
OUTPUT
LEVEL (dBu)
LOW
CUT
EQ
BYPASS
TYPE III
NR
INPUT
GAIN
dB
-12
0
+12
PeakPlus
THRESHOLD
dBu
0 OFF
+20+5
+15+10
+/-6
+/-15
CLIP
13610+18+100-10
0
-15
+15
0
-15
+15
0
-6
+6
0
-6
+6
85-2568-A0 2231 FRONT ART 12-16-96

OPERATION MANUAL
3
20 SERIES GRAPHIC EQUALIZERS
2215-dualchannel15bandgraphicequalizer
Input Gain Control: Thiscontrolsetsthesignalleveltotheequalizer.Itiscapableof-12dBto+12dBofgain.Its
effectisapparentbyviewingtheOUTPUTLEVELBARGRAPH.
EQ Bypass: Thisswitchremovesthegraphicequalizersectionfromthesignalpath.(SeeBlockdiagramonPage
32.)TheBYPASSswitchdoesnot,however,affecttheINPUTGAIN,orLOWCUTfilters.
EQ Bypass LED:ThisredLEDlightswhentheEQisinbypassmode.Notethatbypassmodeonlyeffectsthe
graphic equalizer section of the 20 Series EQs. TheINPUTGAIN and and LOWCUT controls remain unaffected
when the EQ is bypassed.
Boost/Cut Range Selection Switch and LEDs: Thisswitchselectswhichofthetwoboost/cutrangestheequalizer
willuse,either±6dBor±15dB.TheredLEDlightswhenthe±15dBrangeisselected,andtheyellowLEDlights
whenthe±6dBrangeisselected.NotethattheBOOST/CUTswitchisslightlyrecessed.Thisistopreventacciden-
talactivationoftheswitch,possiblycausingdamagetoothersoundsystemcomponents.
Output Level Bar Graph: ThesefourLEDsindicateoutputleveloftheequalizer.TheredLEDis3dBbelowclip-
pingandismarkedas+18dBu.Itmonitorsthelevelattheoutputoftheequalizerafterallotherprocessing,includ-
ing the limiter.
Clip LED: ThisLEDlightswheneveranyinternalsignallevelreaches3dBbelowclippingwhichmayoccurwhen
anyofthefollowinghappen:1)theinputsignalis“hotter”than+22dBu,2)excessivegainisappliedbytheinput
gaincontrol,or3)excessiveboostisappliedusingthefrequencysliders.
Gain Reduction Meter: ThesefourLEDsindicatetheamountofgainreductionbeinginducedbythesettingofthe
PeakPlus™LIMITERTHRESHOLDcontrol as the signal level from the graphic EQ section exceeds this limiter
threshold setting.
PeakPlus™ Limiter Threshold Control:ThiscontrolengagesthePeakPlus™limiter.Itsetsthethresholdlevelat
which ∞:1gainreductionwillbegintooccur.Itsdesignisborrowedfromthepatent-pendingPeakStopPlus™
Limiterfoundonthepopulardbx1066and1046compressor/limiters.Itiscapableofarangeof0dButhrough
“OFF”(+24dBu).Whenthethresholdcontrolissetto“OFF”,thelimiteriseffectivelydisabled,andnogainreduc-
tion will occur.
dbx Type III™ Noise Reduction Switch: TheswitchengagesthedbxTypeIII™NoiseReductioncircuitwithin
the EQ.
dbx Type III™ Noise Reduction LED:TheyellowLEDlightswhenthedbxTypeIII™NoiseReductioncircuitis
activated via theNOISEREDUCTIONSwitch.
Frequency Band Slider Controls: Each one of these slider potentiometers will boost or cut at its noted frequency
by±6dBor±15dB,dependinguponthepositionoftheBOOST/CUTRANGEswitch.Whenalltheslidersarein
thecenterdetentedpositiontheoutputoftheequalizerisflat.Thefrequencybandcentersofthe2031andthe2231
aremarkedat1/3rdofanoctaveintervalsonISOstandardspacings,whilethefrequencybandcentersofthe2215
aremarkedat2/3rdsofanoctaveintervalsonISOstandardspacings.
Low Cut Enable Switch: TheLOW-CUTswitchinsertsorremovesthe18dB/octave40HzBessellow-cutfilter
fromthesignalpath.WhentheLOW-CUTswitchispushedin,theLOW-CUTfilterisINtheaudiopath.
RANGE
GAIN
REDUCTION (dB)
OUTPUT
LEVEL (dBu)
LOW
CUT
EQ
BYPASS
TYPE III
NR
INPUT
GAIN
dB
-12
0
+12
PeakPlus
THRESHOLD
dBu
0 OFF
+20+5
+15+10
+/-6
+/-15
CLIP
1
0
-6
+6
25 40 63 100 160 250 400 16k10k6.3k4k630 1k 1.6k 2.5k
3610+18+100-10
2215
Equalizer/Limiter
with TYPE III NR
85-XXXX-A0 2215 FRONT ART 12-16-96
0
-15
+15
RANGE
GAIN
REDUCTION (dB)
OUTPUT
LEVEL (dBu)
LOW
CUT
EQ
BYPASS
TYPE III
NR
INPUT
GAIN
dB
-12
0
+12
PeakPlus
THRESHOLD
dBu
0 OFF
+20+5
+15+10
+/-6
+/-15
CLIP
1
0
-6
+6
25 40 63 100 160 250 400 16k10k6.3k4k630 1k 1.6k 2.5k
3610+18+100-10
0
-15
+15

4
OPERATION MANUAL
ConneCting the eQtoyour systeM
The 20 Series Equalizers have balanced inputs and outputs that can be used with any balanced or unbalanced line-
leveldevice.Formorespecificinformationaboutcablingpossibilities,pleaserefertothesectionentitled
Installation Considerations, Page 5.
To connect the equalizer to your sound system refer to the following steps:


Install the EQs in a rack with the rack screws provided. It can be mounted above or below anything that does
notgenerateexcessiveheat.Ambienttemperaturesshouldnotexceed113°F(45°C)whenequipmentisinuse.
Althoughtheunit’schassisisshieldedagainstradiofrequencyandelectromagneticinterference,extremely
highfieldsofRFandEMIshouldbeavoided.

All three types of connectors for the inputs and outputs can be used for balanced or unbalanced connections.
Theuseofmorethanoneconnectoratatimefortheinputscouldunbalancebalancedlines,causephasecancel-
lation,shortaconductortoground,orcausedamagetootherequipmentconnectedtotheequalizer.Morethan
oneoutputmaybeusedsimultaneouslyaslongasthecombinedparallelloadisgreaterthan600Ω.
BOOST/CUT RANGE SELECTION switch
Note: Be sure to reduce audio levels at the power amplifiers when changing the setting of this switch as it may generate an audible transient.

ConnecttheACpowercordtotheACpowerreceptacleonthebackoftheequalizer.RoutetheACpowercord
to a convenient power outlet away from audio lines. The unit may be turned on and off from the rear panel
power switch or a master equipment power switch. Since the 20 Series Equalizers consume a relatively small
amountofpower,theunitsmaybeleftoncontinuously.
rear panel desCriptions
Rear Panels
2031-singlechannel31bandgraphicequalizer
2231-dualchannel31bandgraphicequalizer
4
#85-1565-P1 2031 REAR ART (12-10-96) buyoff
15 WATTS
POWER
OUTPUT
- +
INPUT
- +
OUTPUT INPUT
PHONE:
TIP
RING
SLEEVE
XLR:
PIN 1
PIN 2
PIN 3
CONNECTOR POLARITY
INPUTOUTPUT
100V 50/60Hz
120V 60Hz
PROFESSIONAL PRODUCTS
A HARMAN INTERNATIONAL
COMPANY
SALT LAKE CITY, UTAH
MADE IN USA
MODEL 2031
EQUALIZER/LIMITER WITH
TYPE III NOISE REDUCTION
MANUFACTURED UNDER ONE OR MORE OF THE FOLLOWING
U.S. PATENTS: 4,234,804 4,316,107 4,329,598 4,331,931 4,377,792
4,403,199 4,409,500 4,425,551 4,434,380 4,454,433 4,471,324
4,473,793 OTHER PATENTS PENDING
WARNING: TO REDUCE THE RISK OF FIRE OR ELECTRIC
SHOCK DO NOT EXPOSE THIS EQUIPMENT TO RAIN OR MOISTURE
RISK OF ELECTRIC SHOCK
DO NOT OPEN
ATTENTION: RISQUE DE CHOC ELECTRIQUE - NE PAS OUVRIR
CAUTION: TO REDUCE
THE RISK OF FIRE REPLACE
ONLY WITH SAME TYPE FUSE.
ATTENTION: UTILISER
UN FUSIBLE DE RECHANGE DE
MEME TYPE.
#85-2569-P0 2231 REAR ART (12-10-96) buyoff
28 WATTS
OUTPUT INPUT
PHONE:
TIP
RING
SLEEVE
XLR:
PIN 1
PIN 2
PIN 3
CONNECTOR POLARITY
INPUTOUTPUT
OUTPUT INPUT
INPUTOUTPUT
100V 50/60Hz
120V 60Hz
PROFESSIONAL PRODUCTS
A HARMAN INTERNATIONAL
COMPANY
SALT LAKE CITY, UTAH
MADE IN USA
MODEL 2231
EQUALIZER/LIMITER WITH
TYPE III NOISE REDUCTION
WARNING: TO REDUCE THE RISK OF FIRE OR ELECTRIC
SHOCK DO NOT EXPOSE THIS EQUIPMENT TO RAIN OR MOISTURE
RISK OF ELECTRIC SHOCK
DO NOT OPEN
ATTENTION: RISQUE DE CHOC ELECTRIQUE - NE PAS OUVRIR
CAUTION: TO REDUCE
THE RISK OF FIRE REPLACE
ONLY WITH SAME TYPE FUSE.
ATTENTION: UTILISER
UN FUSIBLE DE RECHANGE DE
MEME TYPE.
POWER
MANUFACTURED UNDER ONE OR MORE OF THE FOLLOWING
U.S. PATENTS: 4,234,804 4,316,107 4,329,598 4,331,931 4,377,792
4,403,199 4,409,500 4,425,551 4,434,380 4,454,433 4,471,324
4,473,793 OTHER PATENTS PENDING
OUTPUT
- +
INPUT
- +
OUTPUT
- +
INPUT
- +

OPERATION MANUAL
5
20 SERIES GRAPHIC EQUALIZERS
2215-dualchannel15bandgraphicequalizer
Power Cord Receptacle: Connects AC power to the equalizer.
Power Switch: Switches the power on and off. Always make audio connections with the power switch in the OFF
position.
Input Connectors: Threetypesofinputconnectorsareprovidedforinputconnections:femalelockingXLRtype
connectors,1/4”tip-ring-sleevephonejackconnectors,andabarrierstrip.Themaximuminputlevelthattheequal-
izercanacceptis+22dBu(ref:0.775Vrms).
Output Connectors:Threetypesofoutputconnectorsareprovidedforoutputconnections:maleXLRtypecon-
nectors,1/4”tip-ring-sleevephonejackconnectorsandabarrierstrip.
Byremovingthejumperconnectingthetwoscrewsonthebarrierstrip,thechassis
groundisseparatedfromthecircuitgroundoftheequalizer.Thisissometimesnecessarytoprevent“groundloops”
inasoundsystem.Whenliftingthegroundstrap,youmustmakeaconnectionfromthecircuitground(
++
+
++ +
++
Without Jumper in Place With Jumper in Place
jumper
optional
circuit
ground
chassis
ground
circuit
ground
chassis
ground
to system
ground
optional
WIRING CONNECTIONS WITH GROUND
Input
Cable
Output
Cable
Input
Cable
Output
Cable
) terminal
to some other ground point in your audio system in order for the equalizer to function properly.
installation Considerations
Hookups and Cabling: The20SeriesEqualizersaredesignedfornominal+4dBulevels.Theequalizerscanbe
usedwitheitherbalancedorunbalancedsources,andtheoutputscanbeusedwitheitherbalancedorunbalanced
loads,providedthepropercablingisused.
A balanced line is defined as two-conductor shielded cable with the two center conductors carrying the same signal
but of opposite polarity when referenced to ground. An unbalanced line is generally a single-conductor shielded
cable with the center conductor carrying the signal and the shield at ground potential.
Theequalizerhasaninputimpedanceof40kΩ balanced and 20kΩunbalanced. This
makes the 20 Series Equalizers’ audio inputs suitable for use with virtually any low source impedance (under 2kΩ).
Theequalizer’soutputiscapableofdrivinga600Ωloadto+18dBu.Formaximum
humrejectionwithabalancedsource,avoidcommongroundingattheequalizer’sinputsandoutputs.Mostbal-
anced (3-conductor) cables have the shield connected at both ends. This can result in ground loops which cause
hum.Ifhumpersiststrydisconnectingtheshieldononeormoreofthecablesinthesystem,preferablyattheinput
ofadevice,notattheoutput.
5
#85-2563-P2 2215 REAR ART (12-17-96) buyoff
OUTPUT
- +
INPUT
- +
OUTPUT INPUT
PHONE:
TIP
RING
SLEEVE
XLR:
PIN 1
PIN 2
PIN 3
CONNECTOR POLARITY
INPUTOUTPUT
OUTPUT
- +
INPUT
- +
OUTPUT INPUT
INPUTOUTPUT
PROFESSIONAL PRODUCTS
A HARMAN INTERNATIONAL
COMPANY
SALT LAKE CITY, UTAH
MADE IN USA
MODEL 2215
EQUALIZER/LIMITER WITH
TYPE III NOISE REDUCTION
MANUFACTURED UNDER ONE OR MORE OF THE FOLLOWING
U.S. PATENTS: 4,234,804 4,316,107 4,329,598 4,331,931 4,403,199
4,409,500 4,425,551 4,434,380 4,454,433 4,471,324 4,473,793
OTHER PATENTS PENDING
WARNING: TO REDUCE THE RISK OF FIRE OR ELECTRIC
SHOCK DO NOT EXPOSE THIS EQUIPMENT TO RAIN OR MOISTURE
RISK OF ELECTRIC SHOCK
DO NOT OPEN
ATTENTION: RISQUE DE CHOC ELECTRIQUE - NE PAS OUVRIR
CAUTION: TO REDUCE
THE RISK OF FIRE REPLACE
ONLY WITH SAME TYPE FUSE.
ATTENTION: UTILISER
UN FUSIBLE DE RECHANGE DE
MEME TYPE.
28 WATTS
POWER
100V 50/60Hz
120V 60Hz
++
+
++ +
++
Without Jumper in Place With Jumper in Place
jumper
optional
circuit
ground
chassis
ground
circuit
ground
chassis
ground
to system
ground
optional
WIRING CONNECTIONS WITH GROUND
Input
Cable
Output
Cable
Input
Cable
Output
Cable
Wiring Connections With Ground

6
OPERATION MANUAL
operation and appliCation notes
Thedbx20SeriesGraphicEqualizersareusefulaudiosignalprocessingtoolsinsituationswhereprecisefrequency
control is required across the audible frequency spectrum.
When used with an audio spectrum analyzer the EQs can tune any acoustical environment -- from the studio to the
concerthall--tostopringing,increaseclarity,andflattentheoverallfrequencyresponseoftheenvironment.A
real-time spectrum analyzer or other types of audio environment analyzers are very useful in determining the
amount of equalization needed.
Insert the graphic equalizer between the signal source (usually a mixer) and the power amplifiers (or the crossover if
thereisone).Adjustthelevelandequalizationasrequiredtoyieldthedesiredsystemresponse.Thelongthrowfad-
ers of the EQs allow very precise settings of the equalization for accurate equalization curves.
Foroptimumsignal-to-noiseresponse,thegainstructureofthesoundsystemmustbeproperlysetup.Eachcompo-
nentofthesoundsystemshouldbesetatitsnominaloperatinglevel,startingwiththefirstelementinthesystem,
usually a mixing console. Each element should be run at its nominal operating level in order to take advantage of
themaximumsignal-to-noisepropertiesofthatelement.Loudspeakeramplifiers,asthelastelementinthechain,
shouldbesetonlyasloudasnecessary,inordertoavoidinducingunnecessarynoiseintothesystem.
Allactiveequalizers,bynatureofdesign,addnoisewhenboostingorcuttingthatcaneasilydegradetheotherwise
acceptablesignal-to-noiseratioofasoundsystem.Drasticequalizationcanresultinalossof20dBormoresignal-
to-noise.dbxTypeIII™NoiseReductionwasengineeredspecificallyforapplicationssuchasthis.Itprovidesupto
20dBofnoisereduction,thusrestoringthedynamicrangenecessaryforeventhemostdemandingprofessional
soundsystems.Thecombinationofproperwiring,propergainstructureandTYPEIII™NoiseReductionshould
render your sound system virtually noise free.
teChniCal support / FaCtory serviCe
The dbx 20 Series EQs are all solid-state products with components chosen for high performance and excellent reli-
ability.Eachunithasbeentestedandburned-inatthefactory.Noadjustmentofanytypeshouldberequired
throughout the life of the unit.
Ifcircumstancesarisewhichnecessitaterepair,werecommendthatyourEQbereturnedtothefactory.Thiscan
onlybedonebyreceivingaRETURNAUTHORIZATIONnumberfromdbxcustomerservice.
IfyourequiretechnicalsupportcontactCustomerService.Bepreparedtoaccuratelydescribetheproblem.Know
the serial number of your unit (printed on a sticker attached to the chassis of the unit).
Contact information is printed on the back cover of this manual.

OPERATION MANUAL
31
20 SERIES GRAPHIC EQUALIZERS
dbx 2031 Graphic Equalizer
Block Diagram
.....
VCA VCA
40Hz
GRAPHIC
EQ
PeakPlus TM
Limiter
Detector/
Timing
TYPE III NR
Detector/
Timing
PeakPlus TM
Threshold
20Hz 20kHz
EQ
Bypass
±6dB ±15dB
Range
CLIP
Input
Gain
Input
Output
Level
Gain
Reduction
RF Filter RF
Filter
Output

32
OPERATION MANUAL
Inputs / Entrées / Eingänge / Entradas
Connectors:  1/4”TRS,femaleXLR(pin2hot),andbarrierterminalstrip
Connecteurs:  Jacks6,35mm,XLRfemelle(pointchaud=broche2)etbornier
Anschlüsse:  6,3-mm-Stereoklinkenbuchsen,XLR-Buchsenweibl.(Inphase=Stift2)undKlemmleiste
Conectores:  Clavijasjackestéreo6,3mm,XLRhembra(espiga2=enfase)yregletadebornes
Type:  Electronicallybalanced/unbalanced,RFfiltered
Type:  Symétrie,asymétrieélectroniques,filtréescontrelesinterférencesradio
Schaltung:  Elektronischsymmetriert/asymmetrisch,HF-geschützt
Tipo:  Electrónicamentebalanceado/desbalanceado,confiltroRF
Impedance:  Balanced40kΩ,unbalanced20kΩ
MaxInputLevel:  >+21dBubalancedorunbalanced
CMRR:  >40dB,typically>55dBat1kHz
Outputs / Sorties / Ausgänge / Salidas
Connectors:  1/4”TRS,maleXLR(pin2hot),andbarrierterminalstrip
Connecteurs:  Jacks6,35mm,XLRfemelle(pointchaud=broche2)etbornier
Anschlüsse:  6,3-mm-Stereoklinkenbuchsen,XLR-Buchsenmännl.(Inphase=Stift2)undKlemmleiste
Conectores:  Clavijasjackestéreo6,3mm,XLRmacho(espiga2=enfase)yregletadebornes
Type:  Balanced/unbalanced,RFfiltered
Type:  Symétrique,asymétrique
Schaltung:  Impedanzsymmetriert/asymmetrisch,HF-geschützt
Tipo:  Balanceadoporimpedancia/desbalanceado,confiltroRF
Impedance:  Balanced120Ω,unbalanced60Ω
MaxOutputLevel: >+21dBubalanced/unbalancedinto2kΩor greater
  >+18dBmbalanced/unbalanced(into600Ω)

Bandwidth:  20Hzto20kHz,+0.5/-1dB
FrequencyResponse: <10Hzto>50kHz,+0.5/-3dB
NoiseReductionIn (+/-6and+/-15dBrange):
Signal-to-Noise:  >100dB,unweighted,ref:+4dBu,22kHzmeasurementbandwidth
DynamicRange:  >118dB,unweighted
NoiseReductionOut: (+/-6dBrange):
Signal-to-Noise:  >94dB,unweighted,ref:+4dBu,22kHzmeasurementbandwidth
DynamicRange:  >112dB,unweighted
NoiseReductionOut: (+/-15dBrange):
Signal-to-Noise:  >90dB,unweighted,ref:+4dBu,22kHzmeasurementbandwidth
DynamicRange:  >108dB,unweighted
THD+Noise:  <0.04%,0.02%typicalat+4dBu,1kHz
  <0.5%at1kHzwith15dBgainreduction
InterchannelCrosstalk: <-80dB,20Hzto20kHz(2215/2231)
NoiseReduction:  Upto20dBofdynamicbroadbandnoisereduction

TYPE III NR:  ActivatesdbxTypeIII™NoiseReduction
  ActivelaréductiondebruitdbxTypeIII™
  SchaltetdbxTypeIII™Rauschunterdrückungeinundaus
  ActivalaReduccióndeRuidodbxTypeIII™
EQ BYPASS:  Bypassesthegraphicequalizersectioninthesignalpath
  ”Bypasse”lasectioncorrecteurgraphique
Schaltet den graphischen Equalizerteil aus dem Signalweg aus
  Haceunaderivacióndelaseccióndeecualizadorgráficoenelcaminodelaseñal
LOW CUT(recessed): Activatesthe40Hz18dB/octaveBesselhigh-passfilter
 (enfoncé): Activelefiltrepasse-haut40Hz18dB/octavedetypeBessel
 (versenkt): SchaltetdasBessel-Hochpassfilter(40Hz,18dB/Oktave)einundaus
 (empotrado): ActivaelfiltrodepasoaltodeBesselde40Hz,18dB/octava
RANGE (recessed): Selectseither+/-6dBor+/-15dBsliderboost/cutrange
 (enfoncé): Sélectionnelaplaged’atténuation/accentuation+/-6dBou+/-15dB
 (versenkt): SchaltetdenRegelbereichderSchiebereglerzwischen+/-6dBund+/-15dBum.
 (empotrado): Seleccionaunadelasdosgamasrefuerzo/cortedelosdeslizadores:+/-6dBó+/-15dB
speCiFiCations / CaraCtéristiQues teChniQues /teChnisChe daten /
espeCiFiCaCiones

OPERATION MANUAL
33
20 SERIES GRAPHIC EQUALIZERS

OUTPUT LEVEL: 4-LEDbargraph(Green,Green,Yellow,Red)at-10,0,+10,and+18dBu
  VUmètre4-Leds(verte,verte,jaune,rouge)à-10,0,+10,et+18dBu
  4-teiligeLED-Zeile(grün-grün-gelb-rot)bei-10,0.+10,+18dBu
  4LEDs(verde,verde,amarillo,rojo)a-10,0,+10y+18dBu
GAIN REDUCTION: 4-LEDbargraph(allRed)at0,3,6,and10dB
  VUmètre4-Leds(toutesrouges)à0,3,6,et10dB
  4-teiligeLED-Zeile(4xrot)bei0,3,6,10dB
  4LEDsrojosa0,3,6y10dB
TYPE III NR:  1LED:yellow/jaune/gelb/amarillo
EQ BYPASS:  1LED:red/rouge/rot/rojo
CLIP:  1LED:red/rouge/rot/rojo
LOW CUT:  1LED:red/rouge/rot/rojo
  1LED:yellow/jaune/gelb/amarillo
:  1LED:red/rouge/rot/rojo

OperatingVoltage: 100VAC50/60Hz,120VAC60Hz;230VAC50/60Hz
Tension:
Netzspannung: 
Tensiónderegimen:
PowerConsumption: 203115W;221528W;223128W
Consommation:
Leistungsaufnahme:
Consumo de energía:
MainsConnection: IECreceptacle
Connecteursecteur: PrisechâssisIEC
Netzanschluss:  IEC-Kaltgerätebuchse
Conexióndered:  tomacorrienteIEC

Dimensions:  2031/2215:3.5”HX19”WX7.9”D(8.9cmx48.3cmx20.1cm)
  2231:5.25”HX19”WX7.9”D(13.4cmx48.3cmx20.1cm)
Dimensions(hxlxp):
Abmessungen(HxBxT):
Dimensiones(alxanxprf: 2031/2215:89x483x201mm
  2231:134x483x201mm
Weight:  2031:7.5lbs.
  2215:8.5lbs.
  2231:10.6lbs.
Poids:  2031:3.4kg
Nettogewicht:  2215:3.9kg
Pesoneto  2231:4.8kg
ShippingWeight:  2031:8.5lbs.
  2215:9.5lbs.
  2231:11.6lbs.
Poidsàl’expédition: 2031:3,8kg
Bruttogewicht:  2215:4,3kg
Pesodeembarque:  2231:5,3kg
Note:Specificationssubjecttochange.
Note:Caractéristiquessujettesàmodifications.
Anm.: Technische Änderungen vorbehalten.
Nota:Especificacionessujetasacambio.

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Part No: 18-2276V-C - Printed in China