Mackie SRM1850 User manual

OWNER’S MANUAL
1600W 18" POWERED SUBWOOFER
SRM1850

SRM1850 Powered Subwoofer
2
SRM1850 Powered Subwoofer
1. Read these instructions.
2. Keep these instructions.
3. Heed all warnings.
4. Follow all instructions.
5. Do not use this apparatus near water.
6. Clean only with a dry cloth.
7. Do not block any ventilation openings. Install in accordance with the manu-
facturer’s instructions.
8. Do not install near any heat sources such as radiators, heat registers, stoves,
or other apparatus (including amplifiers) that produce heat.
9. 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
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.
10. Protect the power cord from being walked on or pinched particularly at plugs,
convenience receptacles, and the point where they exit from the apparatus.
11. Only use attachments/accessories specified by the manufacturer.
12. Use only with a cart, stand, tripod, bracket, or table
specified by the manufacturer, or sold with the
apparatus. When a cart is used, use caution when
moving the cart/apparatus combination to avoid injury
from tip-over.
13. Unplug this apparatus during lightning storms or when
unused for long periods of time.
14. 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.
15. This apparatus shall not be exposed to dripping or splashing, and no object
filled with liquids, such as vases or beer glasses, shall be placed on the
apparatus.
16. Do not overload wall outlets and extension cords as this can result in a risk
of fire or electric shock.
17. This apparatus has been designed with Class-I construction and must be
connected to a mains socket outlet with a protective earthing connection
(the third grounding prong).
18. This apparatus has been equipped with a rocker-style AC mains power
switch. This switch is located on the rear panel and should remain readily
accessible to the user.
19. The MAINS plug or an appliance coupler is used as the disconnect device,
so the disconnect device shall remain readily operable.
20.NOTE: This equipment has been tested and found to comply with
the limits for a Class B digital device, pursuant to part 15 of the FCC
Rules. These limits are designed to provide reasonable protection
against harmful interference in a residential installation. This equipment
generates, uses, and can radiate radio frequency energy and, if not
installed and used in accordance with the instructions, may cause
harmful interference to radio communications. However, there is no
guarantee that interference will not occur in a particular installation.
If this equipment does cause harmful interference to radio or television
reception, which can be determined by turning the equipment off and
on, the user is encouraged to try to correct the interference by one or
more of the following measures:
• Reorientorrelocatethereceivingantenna.
• Increasetheseparationbetweentheequipmentandthereceiver.
• Connecttheequipmentintoanoutletonacircuitdifferentfromthat
to which the receiver is connected.
• Consultthedealeroranexperiencedradio/TVtechnicianforhelp.
CAUTION: Changes or modifications to this device not expressly approved
by LOUD Technologies Inc. could void the user's authority to operate the
equipment under FCC rules.
21. This apparatus does not exceed the Class A/Class B (whichever is
applicable) limits for radio noise emissions from digital apparatus as set
out in the radio interference regulations of the Canadian Department of
Communications.
ATTENTION —
Le présent appareil numérique n’émet pas de bruits radioélec-
triques dépassant las limites applicables aux appareils numériques de class
A/de class B (selon le cas) prescrites dans le réglement sur le brouillage
radioélectrique édicté par les ministere des communications du Canada.
22. Exposure to extremely high noise levels may cause permanent hearing
loss. Individuals vary considerably in susceptibility to noise-induced hearing
loss, but nearly everyone will lose some hearing if exposed to sufficiently
intense noise for a period of time. The U.S. Government’s Occupational
Safety and Health Administration (OSHA) has specified the permissible
noise level exposures shown in the following chart.
According to OSHA, any exposure in excess of these permissible limits
could result in some hearing loss. To ensure against potentially dangerous
exposure to high sound pressure levels, it is recommended that all persons
exposed to equipment capable of producing high sound pressure levels
use hearing protectors while the equipment is in operation. Ear plugs or
protectors in the ear canals or over the ears must be worn when operating
the equipment in order to prevent permanent hearing loss if exposure is in
excess of the limits set forth here:
PORTABLE CART
WARNING
CAUTION
RISK OF ELECTRIC SHOCK. DO NOT OPEN
CAUTION: TO REDUCE THE RISK OF ELECTRIC SHOCK DO NOT REMOVE COVER (OR BACK)
NO USER-SERVICEABLE PARTS INSIDE. REFER SERVICING TO QUALIFIED PERSONNEL
The lightning flash with arrowhead symbol within an equilateral triangle is
intended to alert the user to the presence of uninsulated "dangerous
voltage" within the product's enclosure, that may be of sufficient magnitude
to constitute a risk of electric shock to persons.
The exclamation point within an equilateral triangle is intended to alert the
user of the presence of important operating and maintenance (servicing)
instructions in the literature accompanying the appliance.
WARNING — To reduce the risk of fire or electric shock, do not
expose this apparatus to rain or moisture.
Duration, per
day in hours Sound Level dBA,
Slow Response Typical Example
8 90 Duo in small club
6 92
4 95 Subway Train
3 97
2 100 Veryloudclassicalmusic
1.5 102
1 105 John screaming at Troy about deadlines
0.5 110
0.25 or less 115 Loudest parts at a rock concert
Correct Disposal of this product: This symbol indicates that this product should not be disposed of with your household waste, according to the WEEE Directive
(2002/96/EC) and your national law. This product should be handed over to an authorized collection site for recycling waste electrical and electronic equipment (EEE). Improper handling
of this type of waste could have a possible negative impact on the environment and human health due to potentially hazardous substances that are generally associated with EEE. At the
same time, your cooperation in the correct disposal of this product will contribute to the effective usage of natural resources. For more information about where you can drop off your waste
equipment for recycling, please contact your local city office, waste authority, or your household waste disposal service.
Important Safety Instructions
CAUTION — To prevent electric shock hazard, do not connect
to mains power supply while grille is removed.

Owner’s Manual
3
Owner’s Manual
Contents Features
Part No. SW0986 Rev. A 08/13
©2013 LOUD Technologies Inc. All Rights Reserved.
• 1600Wofintensepowerpairedwithacustom
  high-output18"wooferdeliverschest-pounding
  lowendperformance
•“Built-Like-A-Tank”all-wood,internally-braced
  cabinetdeliversprofessional-graderoad-
  worthinessandnear-zerodistortion,even
  athighvolume
•Frontportedformaximumlow-frequency 
  extensionandpunch
• StereoXLRinputsplusstereoXLRfull-range
  andhigh-passoutputs
•Integrateddigitalcrossoverwithvariable
  controlandpresetsfortheSRM550and
  SRM650loudspeakers
• SmartProtect™DSPkicksintoprotectyour 
  investmentwhenthingsgetpushedalittle
  toohard
•Built-incupforeasilypole-mountingfull-range
  loudspeakers
Important Safety Instructions .................................. 2
Contents................................................................. 3
Features................................................................. 3
Introduction............................................................ 4
How To Use This Manual ......................................... 4
Getting Started....................................................... 4
Things To Remember................................................ 4
Hookup Diagrams.................................................... 5
SRM1850 Subwoofer: Rear Panel Features .............. 9
1. Power Connection ......................................... 9
2. Power Switch ............................................... 9
3. XLR Inputs ................................................... 9
4. Normal / Invert Switch [Polarity]................ 10
5. Gain Knob .................................................. 10
6. High Pass Outputs ...................................... 10
7. Full Range Outputs...................................... 10
8. Stereo / Mono Switch [Full Range].............. 11
9. High Pass Mode.......................................... 11
10. Main Logo Switch / Limit LED.................... 11
11. Extra Knobs, Buttons and LEDs .................. 11
12. Rock ‘n Roll.............................................. 11
Placement............................................................. 12
Care and Maintenance ........................................... 12
The Ins and Outs of Polarity .................................. 12
Smart Protect ....................................................... 13
Limiting.......................................................... 13
Overexcursion Protection ................................ 13
Thermal Protection.......................................... 13
AC Power............................................................. 13
Appendix A: Service Information ............................ 14
Appendix B: Connections ....................................... 15
Appendix C: Technical Information .......................... 16
SRM1850 Subwoofer Dimensions .................... 17
SRM1850 Subwoofer Frequency Response ....... 17
SRM1850 Subwoofer Block Diagram................ 18
Limited Warranty.................................................. 19
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SRM1850 Powered Subwoofer
4
SRM1850 Powered Subwoofer
Getting Started
Introduction
TheSRM185018"PoweredSubwooferis“Built-like-
a-Tank,”delivering1600Wofintensepowerpaired
withacustomhigh-outputwooferforpowerful,chest-
poundinglowendperformance.Theprofessional-grade,
internally-bracedall-woodenclosureprovidestourlevel
road-worthinessandisfrontportedformaximum
low-frequencyextensionandpunch.
TheSRM1850featuresstereoXLRinputs,full-range
andhigh-passoutputsplusavariabledigitalcrossover
thatincludespresetsfortheSRM550andSRM650
loudspeakers.
TheSmartProtect™DSPisalsoinplacetoprotect
yourinvestmentwhenthingsgetpushedalittletoo
hard.Getthepowerfullowendyourmusicdemands
inarocksolidsubwooferwithourprovenperformance.
How to Use This Manual:
Afterthisintroduction,agettingstartedguidewill
helpyougetthingssetupfast.Thehookupdiagrams
showsometypicalsetups,whiletheremainingsections
providedetailsoftheSRM1850subwoofer.
Thisiconmarksinformationthatiscritically
importantoruniquetothesubwoofer.For
yourowngood,readandrememberthem.
Thefollowingstepswillhelpyousetupthe
subwoofersquickly.
1.Makeallinitialconnectionswiththepower
switchesOFFonallequipment.Makesurethemaster
volume,level,orgaincontrolsareallthewaydown.
2.Connecttheline-leveloutputsfromthemixing
console(orothersignalsource)totheXLRinputson
therearpaneloftheSRM1850subwoofers.
3.ConnectthehighpassoutputsfromtheSRM1850
subwooferstotheinputsofpoweredloudspeakers
(ortoanamplierpoweringpassiveloudspeakers).
4.ConnectthesuppliedACpowercordstothe 
IECsocketsontherearpanelofeachsubwoofer. 
PlugtheotherendintoanACoutletproperlycongured
withthecorrectvoltageasindicatedbelowtheIEC
socket.
5.Turnthemixer(orothersignalsource)on.
6.Turnthesubwooferson.
7.Turntheloudspeakerson.
8.Startthesignalsourceandraisethemixer’s
mainL/Rfaderupuntilaudiomaybeheard.
9.Adjustthemastervolumeofthemixertoa
comfortablyloudlisteninglevel.
10.Readtherestofthismanualtolearnhowtoset
thehighpassmodetoreallydialinasoundforthe
venue.
Things to Remember:
• Neverlistentoloudmusicforprolongedperiods.
  PleaseseetheSafetyInstructionsonpage2for
  informationonhearingprotection.
• Asageneralguide,themixer(orothersignal
  source)shouldbeturnedonrst,SRM1850 
  subwoofersnext,andloudspeakerslast.Assuch,
  theloudspeakersshouldalsobeturnedoffrst,
  followedbythesubwoofers,thenthemixer. 
  Thiswillreducethepossibilityofanyturn-on
  orturn-offthumpsandothernoisesgenerated
  byanyupstreamequipmentfromcomingoutof
  thespeakers.
• Savetheshippingboxesandpackingmaterials!
  Youmayneedthemsomeday.Besides,the 
  catswillloveplayinginthemandjumpingoutat
  youunexpectedly.Remembertopretendlikeyou
  aresurprised!
• Saveyoursalesreceiptinasafeplace.

Owner’s Manual
5
Owner’s Manual
Hookup Diagrams
Small Club System
SRM
550
SRM
650
VAR
POWERCONSUMPTION 200W
SIG/OL SIG/OL
POWERCONSUMPTION200W POWERCONSUMPTION200W
SIG/OL SIG/OL
13DELAY1 (300ms)
14DELAY2 (380ms)
15DELAY3 (480ms)
16REVERB+ DLY (250ms)
8K4K2K1K500250125
15
15
10
10
5
5
0
15
15
10
10
5
5
0
TAPE
IN
STRETURN MAINOUT PHONES
FOOTSWITCH
PHONES
TAPE
OUT
L
R
L
(UNBALANCED)
R
0dB=0dBu
MAIN
METERS
RL
OL
4
6
3
10
15
7
10
20
30
0
2
BREAK
(MUTESALLCHANNELS)
PHANTOM
POWER
POWER
STEREO GRAPHIC EQ
FXSEND
MID
2.5kHz
MID
2.5kHz
MID
2.5kHz
MID
2.5kHz
MID
2.5kHz
80Hz
LOW
U
+15-15
U
+15-15
U
+15-15
INSERT
RL
LOWCUT
100Hz
U
GAIN
M
I
C
G
A
I
N
U+50
-20dB +30dB
OL
1
EQ
12kHz
HI
PAN
AUX
U
+15
OO
MON
FX
U
+15
OO
80Hz
LOW
U
+15-15
U
+15-15
U
+15-15
RL
LOWCUT
100Hz
U
GAIN
M
I
C
G
A
I
N
U+50
-20dB +30dB
2
EQ
12kHz
HI
PAN
AUX
U
+15
OO
MON
FX
U
+15
OO
80Hz
LOW
U
+15-15
U
+15-15
U
+15-15
LINEIN 2LINE/HI-ZIN 1
INSERT
BAL/
UNBAL
(MONO) (MONO) (MONO) (MONO)
LINEIN 3
LINEIN 4
BAL/
UNBAL LINEIN 5
RL
LOWCUT
100Hz
GAIN
3/4
EQ
12kHz
HI
PAN
AUX
U
+15
OO
MON
FX
U
+15
OO
80Hz
LOW
U
+15-15
U
+15-15
U
+15-15
RL
LOWCUT
100Hz
GAIN
M
I
C
G
A
I
N
U+50
M
I
C
G
A
I
N
U+50
5/6
EQ
12kHz
HI
LEVEL
SET
LEVEL
SET
LEVEL
SET
LEVEL
SET
PAN
AUX
U
+15
OO
MON
FX
U
+15
OO
GAIN
MICMICMICMIC
80Hz
LOW
U
+15-15
U
+15-15
U
+15-15
U
+20-20
RL
7/8 ST RTN FX RTN
EQ
12kHz
HI
PAN
AUX
U
+15
OO
MON
FX
U
+15
OO
U
+15
FXTO MON
FXMASTER
U
+15
OO
OO
dB
30
20
10
10
OO
40
50
5
5
U
60
dB
30
20
10
10
OO
40
50
5
5
U
60
dB
30
20
10
10
OO
40
50
5
5
U
60
dB
30
20
10
10
OO
40
50
5
5
U
60
dB
30
20
10
10
OO
40
50
5
5
U
60
dB
30
20
10
10
OO
40
50
5
5
U
60
dB
30
20
10
10
OO
40
50
5
5
U
60
dB
30
20
10
10
OO
40
50
5
5
U
60
dB
30
20
10
10
OO
40
50
5
5
U
60
L
R
LINEIN 6
BAL/
UNBAL
L
R
LINEIN 7
LINEIN 8
BAL/
UNBAL
L
R
BAL/
UNBAL
L
R
BAL/
UNBAL
L
R
MONSEND
BAL/
UNBAL
BAL/
UNBAL
MUTE
PRESETS
FXPRESETS
OL OL OL OL OL
INPUTLEVEL
USB
OO
+20
U
TAPELEVEL
OO
+20
U
MON MAIN
1 2 3/4 5/6 7/8
OL
USB THRU
LINE
HI-Z
MAINMIX
MON
EQIN
BYPASS
01BRIGHTROOM
02WARMLOUNGE
03SMALLSTAGE
04WARMTHEATER
05WARMHALL
06CONCERTHALL
07PLATEREVERB
08CATHEDRAL
09CHORUS
10CHORUS+ REV
11DOUBLER
12TAPESLAP
OO
MAX
LINE
HI-Z
MUTE MUTE MUTE MUTE MUTE MUTE
48V
PROFESSIONALMIC/LINE MIXER WITH FX
SRM
550
SRM
650
VAR
SIG/OLSIG/OL
In this example, an SRM1850 subwoofer is connected to two SRM650 loudspeakers. It is a perfect setup
for a small club.
Here, the L/R outputs of a ProFX8 mixer are connected directly to the channel A and B inputs of a single
SRM1850 subwoofer.
The channel A and B high pass outputs of the SRM1850 subwoofer are connected directly to the channel
1 inputs of each SRM650 loudspeaker. Be sure that the gain knob on each is set to “line” or get ready to
be blasted! Select the SRM650 high pass mode on the SRM1850 for a matched system.

SRM1850 Powered Subwoofer
6
SRM1850 Powered Subwoofer
DJ System
SRM
550
SRM
650
VAR
SRM
550
SRM
650
VAR
POWERCONSUMPTION 200WPOWERCONSUMPTION 200W
SIG/OL SIG/OL
POWERCONSUMPTION200W
SIG/OL SIG/OL
POWERCONSUMPTION200W
O
N
Y
X
M
I
C
P
R
E
LR
2 1
MONITOROUT
BAL/UNBAL
USB
BAL/UNBAL
O
N
Y
X
M
I
C
P
R
E
SRM
550
SRM
650
VAR
SIG/OLSIG/OL
Hookup Diagrams continued...
Perhaps you’re a DJ playing bumpin’ tunes in the middle of the night to a crowd that’s groovin’
and dancin’ to your fine selection.
In this example, a laptop is connected to the channel 1 and 2 inputs of an Onyx Blackjack and a set of
headphones are connected to the phones jack.
The L/R monitor outputs of the Onyx Blackjack are connected directly to the channel A inputs of each
SRM1850 subwoofer.
The channel A high pass output of each SRM1850 subwoofer is connected directly to the channel 1
input of each SRM650 loudspeaker. Be sure that the gain knob on each is set to (or near) “line” or get
ready to be blasted! Select the SRM650 high pass mode on each SRM1850 for a matched system.

Owner’s Manual
7
Owner’s Manual
Daisy-Chaining Multiple SRM1850 Subwoofers
Hookup Diagrams continued...
SRM
550
SRM
650
VAR
SRM
550
SRM
650
VAR
SRM
550
SRM
650
VAR
SRM
550
SRM
650
VAR
DL1608 Mixer
To next SRM
subwoofer
input
To next SRM
subwoofer
input
Main
Outs
SRM1850 subwoofers may be daisy-chained via the male XLR connector labeled “FULL RANGE”.
Simply plug the signal source (i.e., mixer output) into the input jack(s), and patch that subwoofer’s
full range jack to the next subwoofers’s input jack, and so on, daisy-chaining multiple SRM1850
subwoofers. See above for a visual representation of daisy-chaining.

SRM1850 Powered Subwoofer
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SRM1850 Powered Subwoofer
Large Club System
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Hookup Diagrams continued...
Here’s how to set up a large club system. In this example, the L/R outputs of a DL1608 mixer are
connected directly to the channel A inputs of two SRM1850 subwoofers. The channel A full range
outputs of these two SRM1850 subwoofers are connected directly to the channel A inputs of another
set of SRM1850 subwoofers. Talk about beefy low end...and we’ve only connected the subs!
The channel A high pass outputs of the last two SRM1850 subwoofers are connected directly to the
channel 1 inputs of the main pair of SRM650 loudspeakers. Be sure that the gain knob on each is set
to (or near) “line” or get ready to be blasted! Select the SRM650 high pass mode on each SRM1850
connected to an SRM650 for a matched system.

Owner’s Manual
9
Owner’s Manual
SRM1850 Subwoofer: Rear Panel Features
1.Power Connection
Thisisastandard3-prongIECpowerconnector.
Connectthedetachablepowercord(includedin 
thepackagingwiththesubwoofer)tothepower
receptacle,andplugtheotherendofthepower 
cordintoanACoutlet.
MakesurethattheACpowerismatchedto
theACpowerindicatedontherearpanel
(belowtheIECreceptacle).
Disconnectingtheplug’sgroundpinis
dangerous.Don’tdoit!
2.Power Switch
Pressthetopofthisrockerswitchinwardstoturnon
thesubwoofer.ThefrontpanelRunningManlogowill
glowwithhappiness...oratleastitwillifthesubwoofer
ispluggedintoasuitableliveACmainssupplyandthe
mainlogoswitch[10]isdisengaged.
Pressthebottomofthisrockerswitchinwardstoturn
offthesubwoofer.
Asageneralguide,themixer(orothersignal
source)shouldbeturnedonrst,SRM1850
subwoofersnext,andloudspeakerslast. 
Assuch,theloudspeakersshouldalsobeturnedoffrst,
followedbythesubwoofers,thenthemixer.Thiswill
reducethepossibilityofanyturn-onorturn-offthumps
andothernoisesgeneratedbyanyupstreamequipment
fromcomingoutofthespeakers.
3.XLR Inputs
BalancedXLRfemaleconnectorsareprovidedforthe
leftandrightinputs.Connectthefull-rangeline-level
signalfromthemixer(orothersignalsource)tothese
inputjacks.
Ifyouareconnectingasinglesubwooferoutput,or
LFE(low-frequencyeffects)outputtothesubwoofer,
youmayuseeithertheAorBinputconnector.
NEVERconnecttheoutputofanamplier
directlytotheinputofthesubwoofer. 
Thiscoulddamagetheinputcircuitryofthe
activesubwoofer.
Theyarewiredasfollows,accordingtostandards
speciedbytheAES(AudioEngineeringSociety):
Balanced XLR Input Connector
Pin1–Shield(ground)
Pin2–Positive(+orhot)
Pin3–Negative(–orcold)
Formoreinformationontheseconnectors,see
AppendixBonpage16.
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SRM1850 Powered Subwoofer
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SRM1850 Powered Subwoofer
SRM1850 Subwoofer: Rear Panel Features continued...
4. Normal/Invert Switch [Polarity]
Thisswitchreversesthepolarityofthesignalgoing
intothesubwooferamplierby180˚.Ithasnoeffecton
thesignalattheoutputs.
Thereisnorightorwrongsettingforthisswitch.
Listentotheoverallblendofthesubwooferwith 
therestofthesystemandselecttheswitchposition
thatgivesyouthebestsoundforyouraudience.
Infact,yoursystemmayvarywhenpositioned 
differentlyandinalternatevenues.Don’tbeafraid
toexperimentwiththepositionofthepolarityswitch.
Seepage12formoreinformation.
5. Gain Knob
Thegainknobadjuststheinputsensitivityofthe
micinputs.Thisallowssignalsfromtheoutsideworld
tobeadjustedtorunthrougheachchannelatoptimal
internaloperatinglevels.Thereis–6dBofgainwiththe
knobfullydown(off),rampingupto6dBofgainfully
up(max).
6. High Pass Outputs
Typically,full-rangeloudspeakersareconnected
tothehighpassoutputsto“split”theworkwiththe
SRM1850subwoofer.Thesubwooferhandlesallofthe
lowfrequenciesandtheloudspeakershandletherest.
Asaresult,itismoreefcientandabitlouder.
BalancedXLRmaleconnectorsareprovided
fortheline-levelAandBhighpassoutputs. 
Thesubwoofer’scrossoversplitstheinputsignalsinto
twofrequencybands.Thelowfrequencyrangebelow
20Hz–200Hzgoestotheinternalamplierthat 
powersthesubwoofer.Thefrequencyrangeabove
20Hz–200Hzissenttotheseline-leveloutputjacks.
Thefrequencyrangedependsonwherethehighpass
mode[9]isset.
Theyarewiredasfollows,accordingtostandards
speciedbytheAES(AudioEngineeringSociety):
Balanced XLR Output Connector
Pin1–Shield(ground)
Pin2–Positive(+orhot)
Pin3–Negative(–orcold)
2
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Balanced XLR Output Connector
7. Full Range Outputs
Connectthefullrangeoutputstotheinputsof 
anotherpoweredsubwoofer,poweredloudspeakers,
ortoanamplierpoweringpassiveloudspeakers.
BalancedXLRmaleconnectorsareprovidedforthe
line-levelAandBfullrangeoutputs.
Thesignalattheseoutputsisadirectcopyofthe
inputsignals.Theseoutputsallowyoutodaisy-chain
multiplesubwoofersand/orsendthefullrangesignals
toloudspeakers.It’sagreatwaytoaddsidells,too!
Theyarewiredasfollows,accordingtostandards
speciedbytheAES(AudioEngineeringSociety):
Balanced XLR Output Connector
Pin1–Shield(ground)
Pin2–Positive(+orhot)
Pin3–Negative(–orcold)
Seepage7tolearnmoreaboutdaisy-chainingSRM
loudspeakers.
Formoreinformationontheseconnectors,see
AppendixBonpage16.
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Owner’s Manual
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Owner’s Manual
SRM1850 Subwoofer: Rear Panel Features continued...
8. Stereo/Mono Switch [Full Range]
Thisswitchallowsyoutochoosewhetherthe 
AandBinputsaresentoutseparately[switchout]or
asamonosumofbothinputs[switchin].
Forexample,ifamixer’sL/Routputsareconnected
totheAandBinputsofanSRM1850subwooferandthe
fullrangeoutputsareconnectedtostrategicallyplaced
SRMloudspeakers,engagetheswitchsothesignalis
mono-summed.Otherwise,you’llgetjusttheleftor
rightsignalfromthemixer’soutputsentfromtheA
andBfullrangeoutputstotheSRMloudspeakers.
9. High Pass Mode
Thehighpassmodeallowsyoutochoosefromalist
ofpresetsforSRMloudspeakers,asnotedbelow.This
optimizesthesubwooferandloudspeakersconnected
totheSRM1850highpassoutputs.IfnotusingSRM550
orSRM650loudspeakers,avariablemodeallowsyouto
selectthebesthighpassmodesuitedforyourPAsystem
from60Hzto120Hz.
Frequenciesbelowthecrossoverfrequencyaresent
tothesubwoofer.Additionally,theSRM550andSRM650
presetsapplyalignmentdelaytothesubwoofercreating
anoptimallyaligned3-waysystem.Frequenciesabove
theselectedcrossoverfrequencyaresenttothehigh
passoutputs[6].Thehighpassmodeshouldbeset
tothelowestfrequencyresponseratingofthemain
loudspeakers.Pressthehighpassmodebutton
repeatedlyuntilthedesiredhighpassmodesetting
LEDilluminates.If“variable”isselected,turnthehigh
passmodeknobtothefrequencyyoudesire.
SRM550–115Hzplusalignmentdelay
SRM650–115Hzplusalignmentdelay
VAR–60Hz–120Hz
10. Main Logo Switch / Limit LED
TheRunningManlogoonthefrontoftheSRM1850
subwooferilluminateswhenthisswitchisdisengaged
andACpowerisavailableatthemainsinput[1].
EngagetheswitchifyoudonotwanttheRunningMan
logotoilluminate.
SRM1850subwoofershaveabuilt-inlimiterthat
helpstopreventtheamplieroutputsfromclipping
oroverdrivingthetransducers.Thelimitindicator
illuminatesyellowwhenthelimiterisactivated.It’s
okayforittoblinkyellowoccasionally,butifitblinks
frequentlyorlightscontinuously,turndownthegain
knob[5]untilitonlyblinksoccasionally.
Excessivelimitingmayleadto
overheating,whichinturntripsthe
thermalprotectcircuitryandinterrupts
theperformance.See‘ThermalProtection’on
page13formoreinformation.
11. Extra Knobs, Buttons and LEDs
What’scoolerthanextrabellsandwhistlesonanew
toy?Well,alotofthings,Isuppose,butthatdidn’tstop
us!TherearpanelofeachSRM1850subwooferis
stackedwithavarietyofextraknobs,buttonsandLEDs.
Weranoutoftime,sowe’renotreallysurewhatanyof
themdoes.Goaheadandexperimentwitheachknob
andbutton.Onceyouhaveanideaofwhateachfeature
isusedfor,besuretodropusalinetoletusknow.We
canrevisethemanualwiththisnewfoundknowledge,
allthankstoyou!
12. Rock ‘n Roll
Congratulations,youhavereachedtheendofthe
featuressection!Atthispoint,youshouldhaveapretty
goodunderstandingofhowtheSRM1850subwoofer
functions.Ifthisistrue,thenextstepistorock‘nroll!
Ifthisisnottrue,headbacktopage9andreadit
alloveragain.ThefollowingpagesdiscussSRM1850
placement,anin-depthlookatpolarityandSmart
Protect,technicalinformationandmore.Checkitout!
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Placement
TheSRM1850subwooferisdesignedtositonthe
oororstage.Itisnotdesignedtobepole-mounted
orsuspended.
Whenpole-mountingloudspeakers,besurethatthe
SRM1850subwoofersarestabilizedandsecuredfrom
fallingoverorbeingaccidentallypushedover.For
stackedscenarios,itishighlysuggestedthatstrapsare
utilized.Failuretofollowtheseprecautionsmayresult
indamagetotheequipment,personalinjury,ordeath.
Thecabinethasnoriggingpointsandis
notsuitableforrigging.NEVERattempt
tosuspendanSRM1850subwooferbyits
handles.
Aswithanypoweredcomponents,protectthemfrom
moistureandextremecoldandfollowtheotherCare
andMaintenancesuggestionsbelow.
Care and Maintenance
YourSRM1850subwooferswillprovidemanyyearsof
reliableserviceifyoufollowtheseguidelines:
• Avoidexposingthesubwooferstomoisture.
Iftheyaresetupoutdoors,besuretheyare
undercoverifrainisexpected.
• Avoidexposuretoextremecold(below
freezingtemperatures).Ifyoumustoperate
thesubwoofersinacoldenvironment,warm
upthevoicecoilsslowlybysendingalow-level
signalthroughthemforabout15minutesprior
tohigh-poweroperation.
• Useadryclothtocleanthecabinets.Onlydo
thiswhenthepoweristurnedoff.Avoidgetting
moistureintoanyoftheopeningsofthe
cabinet,particularlywherethedriversare
located.
The Ins and Outs of Polarity
SRM1850subwoofersincludeaswitchthatallows
youtoquicklyinvertthepolarityofthesubwoofer’s
outputrelativetotheinputsignalitisreceivingfrom
themixerorothersoundsource.Butwhatexactlydoes
thatmean?Asubwooferworksbyliterallypumpingair
asthewooferconemovesinandoutwithrespecttothe
cabinetinwhichitishoused.Itdoessoaccordingtothe
low-frequencyportionofthesignalitreceivesfromthe
soundsource.
Thewooferconeissimplyfollowingthewaveformas
seeninthesinewaveinFigure1.Asthesinewaverises,
thewooferconepushesout.Likewise,asthesinewave
falls,thewooferconepullsintothecabinet.Amusical
signalismuchmorecomplex,ofcourse,butthesame
principleapplies.Movementofthewooferconecauses
airpressurechangesthatweperceiveassound.
Whenthenormal/invert[polarity]switch[4]is
engaged,theoriginalwaveformissimplyreversed180˚
[seeFigure2].Again,thesubwooferconefollowsthe
waveform.However,thistimethewooferconestarts
bypullingintothecabinetfollowedbythewoofercone
pushingout.Ifyouhaveeverexperimentedwitha
subwooferpolarityswitch,youmaynothavenoticed
anychangestothesoundregardlessofitsposition,
especiallyifyouarelisteningtojustthesubwoofer.
Thisisnormal,asourearsperceivethembothatthe
sametime.
Thenormal/invert[polarity]switchcomesinto 
playwhentheSRM1850subwooferispairedwitha
loudspeaker.Ideally,thewooferconesofthesubwoofer
andfullrangeloudspeakerwouldworktogetherby
pushingandpullinginunison.SRM1850subwoofersare
designedtobeusedinabroadrangeofapplications.
Theexibilityprovidedbythepolarityswitchis 
necessarytoensurethatyouarereceivingthebest
possiblesoundfromyoursystem,regardlessofyour
setup.
<–– Time ––>
Figure 1: Normal [0˚]
Amplitude Amplitude
Figure 2: Invert [180˚]
<–– Time ––>
Polarity Waveforms

Owner’s Manual
13
Owner’s Manual
Smart Protect
ThereareadvancedDSPprotectionmechanisms
designedintotheSRM1850tosafeguardthesubwoofers
andampliersfrominadvertentdamage.
Theprotectioncircuitsaredesignedto
protectthesubwoofersunderreasonable
andsensibleconditions.Shouldyouchoose
toignorethewarningsigns[e.g.excessivedistortion],
youcanstilldamagethespeakerintheSRM1850by
overdrivingitpastthepointofamplierclipping. 
Suchdamageisbeyondthescopeofthewarranty.
Limiting
Thedriverhasitsowncompressioncircuitwhich
helpsprotectitfromdamagingtransientpeaks. 
Thecompressorisdesignedtobetransparentand
isnotnoticeableundernormaloperatingconditions.
Overexcursion Protection
A24dB/octavehigh-passlterat30Hzjustprior
tothelow-frequencyamplierpreventsverylow
frequenciesfrombeingamplied.Excessivelow-
frequencyenergycandamagethewooferbycausing
itto“bottomout,”alsoknowasoverexcursion,which
isequivalenttoamechanicalformofclipping.
Thermal Protection
Allampliersproduceheat.TheSRM1850isdesigned
tobeefcientbothelectricallyandthermally.
Intheunlikelyeventoftheamplieroverheating,
abuilt-inthermalswitchwillactivate,mutingthe
signal.
Whentheamplierhascooleddowntoasafe
operatingtemperature,thethermalswitchresetsitself,
andtheSRM1850subwooferresumesnormaloperation.
Ifthethermalswitchactivates,tryturningdownthe
levelcontrolanotchortwoonthemixingconsole(or
thebackofthesubwoofer)toavoidoverheatingthe
amplier.Beawarethatdirectsunlightand/orhotstage
lightsmaybetheculpritofanamplieroverheating.
AC Power
BesuretheSRM1850subwooferispluggedintoan
outletthatisabletosupplythecorrectvoltagespecied
foryourmodel.Itwillcontinuetooperateatlower
voltages,butwillnotreachfullpower.
Besuretheelectricalservicecansupplyenough
amperageforallthecomponentsconnectedtoit.
Werecommendthatastiff(robust)supplyofAC
powerbeusedbecausetheampliersplacehigh 
currentdemandsontheACline.Themorepowerthatis
availableontheline,thelouderthespeakerswillplay
andthemorepeakoutputpowerwillbeavailablefora
cleaner,punchierbass.Asuspectedproblemof“poor
bassperformance”isoftencausedbyaweakACsupply
totheampliers.
Neverremovethegroundpinonthepower
cordoranyothercomponentoftheSRM1850
subwoofer.Thisisverydangerous.

SRM1850 Powered Subwoofer
14
SRM1850 Powered Subwoofer
Appendix A: Service Information
Poor bass performance
• Checkthepolarityoftheconnectionsbetweenthe
  mixerandthesubwoofers.Youmayhaveyour
  positiveandnegativeconnectionsreversedatone
  endofonecable,causingonesubwoofertobe
  out-of-phasewiththeother.
• Poorbassperformancemaybetheresultofbad
  ACpower.Seethesectiontitled‘ACPower’on
  thepreviouspageforfurtherdetails.
Poor sound
• Isitloudanddistorted?Makesurethatyou’renot
  overdrivingastageinthesignalchain.Verifythat
  alllevelcontrolsaresetproperly.
• Istheinputconnectorpluggedcompletelyinto
  thejack?Besureallconnectionsaresecure.
Noise
• Makesureallconnectionstotheactive 
  subwoofersaregoodandsound.
• Makesurenoneofthesignalcablesarerouted
  nearACcables,powertransformers,orother
  EMI-inducingdevices.
• IstherealightdimmerorotherSCR-baseddevice
  onthesameACcircuitastheSRM1850?Usean
  AClinelterorplugthesubwooferintoa 
  differentACcircuit.
Hum
• Trydisconnectingthecableconnectedtothe
  inputjack.Ifthenoisedisappears,itcouldbe
  a“groundloop,”ratherthanaproblemwiththe
  SRM1850subwoofer.Trysomeofthefollowing
  troubleshootingideas:
• Usebalancedconnectionsthroughoutyoursystem
  forthebestnoiserejection.
• Wheneverpossible,plugalltheaudioequipment’s
  linecordsintooutletswhichshareacommon
  ground.Thedistancebetweentheoutletsandthe
  commongroundshouldbeasshortaspossible.
IfyouthinkyourSRM1850hasaproblem,please
checkoutthefollowingtroubleshootingtipsanddo
yourbesttoconrmtheproblem.VisittheSupport
sectionofourwebsite(www.720trees.com)whereyou
willndlotsofusefulinformationsuchasFAQsand
otherdocumentation.Youmayndtheanswertothe
problemwithouthavingtopartwithyoursubwoofer.
Troubleshooting
No power
• Ourfavoritequestion:Isitpluggedin?Makesure
  theACoutletislive[checkwithatesterorlamp].
• Ournextfavoritequestion:Isthepowerswitch
  on?Ifnot,tryturningiton.
• Makesurethelinecordissecurelyseatedinthe
  linecordsocketandpluggedallthewayintothe
  ACoutlet.
• IstheRunningManlogoonthefrontpanel 
  illuminated?Ifnot,makesuretheACoutlet
  islive.Ifso,referto“Nosound”below.
• TheinternalAClinefusemaybeblown.Thisis
  notauserserviceablepart.Ifyoususpectthe
  AClinefuseisblown,pleaseseethe"Repair"
  sectionnext.
No sound
• Istheinputgainknobfortheinputsource 
  turnedallthewaydown?Verifythatallthevolume
  controlsinthesystemareproperlyadjusted.
  Lookatthelevelmetertoensurethatthemixer
  isreceivingasignal.
• Isthesignalsourceworking?Makesurethe 
  connectingcablesareingoodrepairandsecurely
  connectedatbothends.Makesuretheoutput
  levelcontrolonthemixingconsoleisturnedup
  sufcientlytodrivetheinputsofthespeaker.
• Makesurethemixerdoesnothaveamuteonora
  processorloopengaged.Ifyoundsomethinglike
  this,makesurethelevelisturneddownbefore
  disengagingtheoffendingswitch.
• Hasitshutdown?Makesurethereisatleast
  sixinchesoffreespacebehindeachSRM1850
  subwoofer.

Owner’s Manual
15
Owner’s Manual
Repair
Forwarrantyservice,refertothewarranty
informationonpage19.
Non-warrantyserviceisavailableatafactory-
authorizedservicecenter.Tolocatethenearest
servicecenter,visitwww.720trees.com,click“Contact
TechSupport”andselect“LocateaServiceCenter
orDistributor”[3].ServiceforSRM1850subwoofers
livingoutsidetheUnitedStatescanbeobtainedthrough
localdealersordistributors.
Ifyoudonothaveaccesstoourwebsite,youmaycall
theTechSupportdepartmentat1-800-898-3211,
Monday-Friday,duringnormalbusinesshours,Pacic
Time,toexplaintheproblem.TechSupportwilltellyou
wherethenearestfactory-authorizedservicecenteris
locatedinyourarea.
Appendix B: Connections
Balanced XLR Input Connector
EachSRM1850subwooferhastwofemale
XLRinputs.Besurethecablesarewiredper
AES(AudioEngineeringSociety)standards:
Balanced XLR Input Connector
 Pin1–Shield(Ground)
 Pin2–Positive(+orhot)
 Pin3–Negative(–orcold)
Balanced XLR Input Connector
2
31
SHIELD
COLD
HOT
SHIELD
COLD
HOT
3
2
1
Balanced XLR Output Connector
TherearealsofourmalebalancedXLRoutput
connectorsoneachSRM1850subwoofer[twohigh
passandtwofullrange].Besurethecablesarewired
perAES(AudioEngineeringSociety)standards:
Balanced XLR Output Connector
 Pin1–Shield(Ground)
 Pin2–Positive(+orhot)
 Pin3–Negative(–orcold)
SRM1850subwoofersmaybedaisy-chainedviathe
maleXLRconnectorlabeled“FULLRANGE”.Simply
plugthesignalsource(i.e.,mixeroutput)intothe
inputjack(s),andpatchthatsubwoofer’sfullrange
jacktothenextsubwoofer’sinputjack,andsoon,
daisy-chainingmultipleSRM1850subwoofers.See
page7foravisualrepresentationofdaisy-chaining.
Balanced XLR Output Connector
2
1
SHIELD
COLD
HOT
3
SHIELD
COLD
HOT
3
2
1

SRM1850 Powered Subwoofer
16
SRM1850 Powered Subwoofer
SRM1850 Subwoofer Specifications
Appendix C: Technical Information
Acoustic Performance:
Frequency Response (-3 dB) 40 Hz – 120 Hz
Frequency Response (-10 dB) 35 Hz – 150 Hz
Max peak SPL 132 dB
Crossover Point 115 Hz plus alignment delay [SRM550]
115 Hz plus alignment delay [SRM650]
60 Hz–120 Hz [Variable]
Slope 3rd order HP, 4th order LP
Transducer
Woofer Diameter 18 in / 457 mm
Voice Coil Diameter 3.0 in / 76 mm
Subwoofer Diaphragm Material Paper
Magnet Material Ferrite
Power Amplifier
Rated Power 800 watts rms
1600 watts peak
Rated THD < 1%
Cooling Convection
Design Class D
Input/Output
Input Type Female XLR balanced
differential (stereo left/right)
Input Impedance 20 k balanced,
10 k unbalanced
Full Range Outputs Male XLR balanced
(parallel with inputs – mono)
High Pass Outputs Male XLR balanced
Line Input Power
US detachable line cord 90 – 130 VAC, 60 Hz, 200W
EU detachable line cord 190 – 240 VAC, 50 Hz, 200W
AC Connector 3-pin IEC 250 VAC
Power Supply Type Switchmode
Safety Features
Input Protection Peak and RMS limiting,
power supply and amplifier
thermal protection
Display LEDs Defeatable front power ON
(Running Man logo), Front load
power limiter, High Pass Mode,
input signal
Construction Features
Cabinet 18 mm Poplar plywood
Finish High durability black paint
Handles One on each side
Grille Powder-coated 16 gauge steel
Physical Properties
Height 22.5 in / 572 mm
Width 22.2 in / 565 mm
Depth 23.9 in / 608 mm
Weight 64 lb / 29 kg
Mounting Methods
The SRM1850 subwoofer is designed to sit on the floor or
stage. It is NOT designed to be pole-mounted or suspended.
The cabinet has no rigging points and is not suitable for rigging.
Never attempt to suspend the SRM1850 by its handles.
Options
SRM1850 Cover P/N 2036809-24
SPM200 Loudspeaker Pole Mount P/N 2035170-01
Disclaimer
Since we are always striving to make our products better by
incorporating new and improved materials, components, and
manufacturing methods, we reserve the right to change these
specifications at any time without notice.
The “Running Man” figure is a registered trademark of LOUD
Technologies Inc.
All other brand names mentioned are trademarks or registered
trademarks of their respective holders, and are hereby
acknowledged.
©2013 LOUD Technologies Inc.
All Rights Reserved.

Owner’s Manual
17
Owner’s Manual
SRM1850 Subwoofer Dimensions
SRM1850 Subwoofer Frequency Response
SRM550 / SRM650
VARIABLE : HIGH
VARIABLE : LOW
WEIGHT
64 lb
29 kg
22.2 in
565 mm
22.5 in
572 mm
22.0 in
558 mm
23.9 in
608 mm 16.8 in 428 mm
22.8 in
579 mm
23.9 in
608 mm
Normalized to 0 dB SPL
+10
+0
-20
-10
-30
Frequency Response [Hz]
20 200 2000 20000

SRM1850 Powered Subwoofer
18
SRM1850 Powered Subwoofer
SRM1850 Subwoofer Block Diagram
A
ADC
DAC DAC
DAC
DAC
B
A B
ADC
A B
A B
ADC
+ A - + B -
XOver
XOver XOver
A B
+
-
+
-
Limit Limit
Mono
Stereo
USER CONTROLS
DAC
AMP STATUS
Invert
Normal
Polarity
Invert
Delay
FREQ LEVEL
MODE LIMIT
SRM550
SRM650
VARIABLE
LOGO ON / OFF
LIT LOGO
HIGH PASS OUTPUTS
FULL RANGE OUTPUTS
AMP
MAINHIGH PASS
INPUTS
HARDWIRE BUS ANALOG BUS DIGITAL BUS DSP
LEVEL
DETECT
Smart
Protect
Level
High Definition Audio Processing

Owner’s Manual
19
Owner’s Manual
Limited Warranty
Please keep your sales receipt in a safe place.
This Limited Product Warranty (“Product Warranty”) is provided by LOUD Technologies Inc. (“LOUD”)
and is applicable to products purchased in the United States or Canada through a LOUD-authorized
reseller or dealer. The Product Warranty will not extend to anyone other than the original purchaser
of the product (hereinafter, “Customer,” “you” or “your”).
For products purchased outside the U.S. or Canada, please visit www.720trees.com to find contact
information for your local distributor, and information on any warranty coverage provided by the
distributor in your local market.
LOUD warrants to Customer that the product will be free from defects in materials and workmanship
under normal use during the Warranty Period. If the product fails to conform to the warranty then LOUD
or its authorized service representative will at its option, either repair or replace any such nonconforming
product, provided that Customer gives notice of the noncompliance within the Warranty Period to the
Company at: www.720trees.com or by calling LOUD technical support at 1.800.898.3211 (toll-free in
the U.S. and Canada) during normal business hours Pacific Time, excluding weekends or LOUD holidays.
Please retain the original dated sales receipt as evidence of the date of purchase. You will need it to obtain
any warranty service.
For full terms and conditions, as well as the specific duration of the Warranty for this product, please
visit www.720trees.com.
The Product Warranty, together with your invoice or receipt, and the terms and conditions located at
www.720trees.com constitutes the entire agreement, and supersedes any and all prior agreements
between LOUD and Customer related to the subject matter hereof. No amendment, modification or
waiver of any of the provisions of this Product Warranty will be valid unless set forth in a written
instrument signed by the party to be bound thereby.
Need help with the subwoofer?
• Visit www.720trees.com and click Support to find: FAQs, manuals, addendums, and other documents.
• Email us at: t[email protected].
• Telephone [phone] to speak with one of our splendid technical support chaps
(Monday through Friday, normal business hours, Pacific Time).

16220 Wood-Red Road NE
Woodinville, WA 98072 • USA
Phone: [phone]
Toll-free: 800.898.3211
Fax: [phone]
www.720trees.com