SRM450 ACTIVESOUND REINFORCEMENTMONITOR USERS MANUALAND WARRANTY REGISTRATION

CAUTION AVISRISK OF ELECTRIC SHOCK

DO NOT OPENRISQUE DE CHOC ELECTRIQUE

NE PAS OUVRIR

CAUTION: TO REDUCE THE RISK OF ELECTRIC SHOCKDO NOT REMOVE COVER (OR BACK)

NO USER-SERVICEABLE PARTS INSIDEREFER SERVICING TO QUALIFIED PERSONNEL

ATTENTION: POUR EVITER LES RISQUES DE CHOCELECTRIQUE, NE PAS ENLEVER LE COUVERCLE. AUCUN

ENTRETIEN DE PIECES INTERIEURES PAR L'USAGER. CONFIERL'ENTRETIEN AU PERSONNEL QUALIFIE.

AVIS: POUR EVITER LES RISQUES D'INCENDIE OUD'ELECTROCUTION, N'EXPOSEZ PAS CET ARTICLE

A LA PLUIE OU A L'HUMIDITE

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. Le symbole clair avec point de flche l'intrieur d'un triangle quilatral est utilis pour alerter l'utilisateur de la prsence l'intrieur du coffret de "voltage dangereux" non isol d'ampleur suffisante pour constituer un risque d'lctrocution.

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. Le point d'exclamation l'intrieur d'un triangle quilatral est employ pour alerter les utilisateurs de la prsence d'instructions importantes pour le fonctionnement et l'entretien (service) dans le livret d'instruction accompagnant l'appareil.

7. Heat This Mackie product should be situated away from heatsources such as radiators, or other devices which produce heat.

8. Power Sources This Mackie product should be connected to apower supply only of the type described in these operationinstructions or as marked on this Mackie product.

9. Power Cord Protection Power supply cords should be routedso that they are not likely to be walked upon or pinched by itemsplaced upon or against them, paying particular attention to cords atplugs, convenience receptacles, and the point where they exit thisMackie product.

10. Object and Liquid Entry Care should be taken so thatobjects do not fall into and liquids are not spilled into this Mackieproduct.

11. Damage Requiring Service This Mackie product should beserviced only by qualified service personnel when:

A. The power-supply cord or the plug has beendamaged; or

B. Objects have fallen, or liquid has spilled into thisMackie product; or

C. This Mackie product has been exposed to rain; or

D. This Mackie product does not appear to operatenormally or exhibits a marked change in performance;or

E. This Mackie product has been dropped, or its chassisdamaged.

12. Servicing The user should not attempt to service thisMackie product beyond those means described in this operatingmanual. All other servicing should be referred to the Mackie ServiceDepartment.

13. To prevent electric shock, do not use this polarized plug with anextension cord, receptacle or other outlet unless the blades can befully inserted to prevent blade exposure.

Pour prevenir les chocs lectriques ne pas utiliser cette fichepolarise avec un prolongateur, un prise de courant ou une autresortie de courant, sauf si les lames peuvent tre insres fondsans laisser aucune pariie dcouvert.

14. Grounding or Polarization Precautions should be taken sothat the grounding or polarization means of this Mackie product isnot defeated.

15. This apparatus does not exceed the Class A/Class B (whicheveris applicable) limits for radio noise emissions from digital apparatusas set out in the radio interference regulations of the CanadianDepartment of Communications.

ATTENTION Le prsent appareil numrique nmet pas de bruitsradiolectriques dpassant las limites applicables aux appareilsnumriques de class A/de class B (selon le cas) prescrites dans lerglement sur le brouillage radiolectrique dict par les ministeredes communications du Canada.

SAFETY INSTRUCTIONS1. Read Instructions All the safety and operation instructionsshould be read before this Mackie product is operated.

2. Retain Instructions The safety and operating instructionsshould be kept for future reference.

3. Heed Warnings All warnings on this Mackie product and inthese operating instructions should be followed.

4. Follow Instructions All operating and other instructionsshould be followed.

5. Water and Moisture This Mackie product should not be usednear water for example, near a bathtub, washbowl, kitchen sink,laundry tub, in a wet basement, near a swimming pool, swamp orsalivating St. Bernard dog, etc.

6. Ventilation This Mackie product should be situated sothat its location or position does not interfere with its properventilation. For example, the Component should not be situatedon a bed, sofa, rug, or similar surface that may block anyventilation openings, or placed in a built-in installation such as abookcase or cabinet that may impede the flow of air throughventilation openings.

PORTABLE CART WARNING

Carts and stands - TheComponent should be usedonly with a cart or standthat is recommended bythe manufacturer.A Component and cartcombination should bemoved with care. Quickstops, excessive force, anduneven surfaces may causethe Component and cartcombination to overturn.

WARNING To reduce the risk of fire or electricshock, do not expose this appliance to rain or moisture.

3Part No. 820-158-00 Rev. B 7/16/991999 Mackie Designs Inc. All Rights Reserved. Printed in the U.S.A.

Lend Me Your EarsExposure to extremelyhigh noise levels maycause permanent hear-ing loss. Individuals vary

considerably in susceptibility to noise-in-duced hearing loss, but nearly everyone willlose some hearing if exposed to sufficientlyintense noise for a period of time. The U.S.Governments Occupational Safety andHealth Administration (OSHA) has speci-fied the permissible noise level exposuresshown in this chart.

According to OSHA, any exposure inexcess of these permissible limits couldresult in some hearing loss. To ensureagainst potentially dangerous exposure tohigh sound-pressure levels, it is recommend-ed that all persons exposed to equipmentcapable of producing these levels use hearingprotectors while this unit is in operation.Ear plugs or protectors in the ear canals orover the ears must be worn when operatingthis amplification system in order to preventa permanent hearing loss if exposure is inexcess of the limits set forth here.

Duration Per Day Sound Level dBA, Typical In Hours Slow Response Example

8 90 Duo in small club6 924 95 Subway Train3 972 100 Very loud classical music

1.5 1021 105 Patrice screaming at Ron about deadlines

0.5 110 0.25 or less 115 Loudest parts at a rock concert

CONTENTSINTRODUCTION....................................................... 4HOOKUP DIAGRAMS............................................... 6

Quick Start ........................................................ 6REAR PANEL DESCRIPTION .................................... 8

IEC Socket .................................................. 8 POWER Switch ............................................ 8 POWER ON Indicator ................................... 8 TIMED TURNOFF......................................... 8 THERMAL Indicator ..................................... 8 CONTOUR................................................... 9 LOW CUT .................................................... 9 LEVEL ......................................................... 9 SIGNAL PRESENT Indicator ........................ 9 PEAK Indicator ............................................ 9 INPUT Connector ........................................ 9 THRU Connector ......................................... 9 ACCESSORY Plate ...................................... 9

CONNECTIONS...................................................... 10PLACEMENT .......................................................... 10RIGGING ................................................................ 11THERMAL CONSIDERATIONS ................................ 12AC POWER CONSIDERATIONS .............................. 12SERVICE INFORMATION ........................................ 14

Warranty Service ............................................. 14Troubleshooting ............................................... 14Repair ............................................................. 16

CARE AND MAINTENANCE.................................... 16SPECIFICATIONS ................................................... 17BLOCK DIAGRAM .................................................. 18SRM450 LIMITED WARRANTY ............................... 19

Dont forget to visit our website at www.mackie.comfor more information about these and other Mackie products.

The SRM450can produce amaximum SPLof 123 dB @ 1m

4

INTRODUCTIONThank you for choosing Mackie Designs

active sound reinforcement monitors.The SRM450 is an active two-way loud-

speaker system capable of extremely highsound pressure levels, and designed to giveyou the best performance of any loud-speaker in its class and price range.

Our design goal was to build a sound re-inforcement monitor with the same fidelityand flat frequency response found in ourreknowned HR824 studio monitors. Wethink youll agree that the SRM450 soundquality and accuracy reaches this goal andmore. The result is a sound reinforcementsystem worthy of the name Monitor,equally at home in a concert setting, in thestudio, impromptu concerts on the studioroof, in the cinema, or in a home theater.

Mackie Designs entry into the soundreinforcement loudspeaker market beganwith the acquisition, in June of 1998, ofRadio Cine Forniture (RCF), headquarteredin Reggio Emilia, Italy. RCF has a long tra-dition in developing speaker technology forthe high-end pro-audio market.

The TransducersThe SRM450 active monitors feature a

12 high-power low-frequency woofer anda 1.75 titanium diaphragm high-outputprecision compression driver. This highfrequency driver is mounted on an acousti-cally non-resonant exponential waveguide,providing a wide, controlled dispersion andprecise reproduction of the critical uppermid-range and high frequencies. The resultis an unbelievably smooth off-axis responsethat allows everyone in the audience toexperience the same high-resolution audiono matter where they are seated.

Each driver has been specifically designedby our engineers for optimum performancein the lightweight high-strength cabinet.

FR Series Power AmplifiersTo power these beautiful things, each

SRM450 includes two of our acclaimed FRSeries Fast Recovery power amplifiers. Ourexclusive design uses low negative feedback,yet allows the amplifiers to maintain low dis-tortion and stability and to quickly recoverwhen driven into clipping.

The amplifiers include the followingfeatures: The low-frequency amplifier produces

up to 540 watts peak (300 continuous)before clipping.

The high-frequency amplifier producesup to 150 watts peak (100 continuous)before clipping.

Each amplifier has its own compressorcircuit that acts when the input signal islarge enough to cause clipping, distor-tion and excessive voice coil heat. Thecompressor will automatically decreasethe input signal to a safe level. Thecompressor in the low-frequency ampworks independently from that in thehigh-frequency amp.

The low-frequency amp uses a servofeedback loop which senses the currentflowing in the woofer coil. This controlsthe low-frequency response and main-tains low distortion at high output levels.

The low-frequency amplifier also has asweeping filter. This will automaticallymove the low cut-off frequency up ordown depending on the amplifieroutput. For example, if the amplifier isbelow clipping, the low-frequency cut-off point is 55Hz. As it approachesclipping, this shifts up smoothly to120Hz, providing more power reservesand less distortion before clipping. Thishappens quickly and continuously,protecting the amplifer and the wooferand reducing any noticable distortion.

Warning: Although theamplifiers have theseprotection circuits, youmust still make sure thePEAK light is not blink-

ing often or continuously. If it is, turn downyour mixer faders, or preamplifier gain, orturn down the SRM450 LEVEL control.

5

The Crossover

The built-in electronic crossover is a24 dB/octave Linkwitz-Riley design.Although more expensive than other cross-over designs, the benefits provided by theLinkwitz-Riley design have been well docu-mented. These benefits include: Absolutely flat frequency response

throughout the bandpass, without thecharacteristic ripple near the crossoverpoint exhibited by other designs.

The sharp 24 dB per octave roll-off ofthe filters ensures that the transducersarent reproducing frequencies outsideof their capabilities.

The acoustic sum of the two driverresponses is unity at the crossoverfrequency, resulting in perfect powerresponse.

Our heroic engineers have workedcarefully to ensure that the SRM450also provides perfect phase response.This diligence has yielded phenomenalaccuracy, even if you are standing 20feet away.

The Cabinet

The SRM450 cabinet was designed to bethe strongest molded composite cabinet onthe planet. This material is as strong as con-crete, and rigid enough to preventunwanted vibrations in the cabinet. It hasbuilt-in fly points for hanging, and a socketin the bottom for mounting on a tripodstand. Although it is an exceptional choicefor installed sound situations, its lightweight and durable finish also make it idealfor portable sound system use. The asym-metrical trapezoidal design of the cabinetmakes it easy to use as a floor wedge forstage monitor applications.

The Active AdvantageThere are a number of advantages to us-

ing an active speaker system over a passiveloudspeaker: The internal crossover is active, and its

low power circuitry operates on line-level signals. It does not wastespeaker-level power like a passivecrossover with large coils, caps, andresistors.

The input signals are crossed overbefore they reach the amplifiers, so eachamplifier only receives the correctfrequency range for its driver.

The amplifiers are designed specificallyfor these speaker load impedances.There is no guesswork as to what loadeach amplifier has to drive, so they canprovide maximum acoustic output fromthe speakers, yet minimize the danger ofspeaker damage due to overdriving alesser amplifier.

The connecting wires between theamplifier outputs and the drivers arekept to a minimum, so the dampingfactor of the amplifier isnt compro-mised by the resistance of long speakercables. In addition, all the power fromthe amplifier is transferred directly tothe drivers with no speaker cable losses.

The acoustic sum of the outputs fromthe two drivers is optimized electroni-cally, as well as physically, so theamplitude response is flat and there isno lobing error.

The presence of active circuits withinthe speaker cabinet allow the designerto add on extra details, such as a highquality mic/line input section andoptional accessory modules.

In short, all the complex interconnectedcomponents in the system are designed towork in harmony with each other to pro-duce the best possible sound. (Even forUncle Berts star performance on spoons!)

6

HOOKUP DIAGRAMSQuick Start1. Start with the following settings on the

back of the SRM450:Turn the POWER switch off (down).Set the TIMED TURNOFF, CONTOUR,and LOW CUT switches out.

WARNING: Turn theLEVEL control down(counterclockwise)before every use. If not,you could be in for a

startling surprise, especially if the lasttime you used it was with a microphoneand now you want to connect a line-level source.

2. Connect the output from your signalsource (mixing console, microphone,preamp, or other mic- or line-levelsource) directly to the INPUT connectoron the back of the SRM450. It acceptsbalanced line-level signals from mixers,preamplifiers, CD players, tape decks,etc., and accepts direct connections fromdynamic microphones.

3. Connect the supplied AC power cord tothe IEC socket on the back of theSRM450. Plug the other end into an ACoutlet properly configured with thecorrect voltage for your particular model.

4. Turn on your signal source. Make sure itsMaster Volume control (if it has one) isturned all the way down.

5. Turn on the SRM450 POWER switch.6. Start the signal source, whether it be

speaking into a microphone or starting aCD player. Adjust any volume controls onthe signal source for normal operation.

7. Slowly turn up the LEVEL control onthe back of the SRM450 until thedesired volume is reached (and thePEAK light does not come on). Alwayswear hearing protectors if you are closewhen it is playing at high levels.

8. If there is no sound, always turn downthe SRM450 LEVEL control beforeinvestigating. There may be a mixer orpreamplifier mute or tape switchengaged, or a mic switch off.

Mixer orPreamplifier

RightLine levelOutput

LeftLine level

Output

ThruThru

Next

Next

1202-VLZPRO

1202-VLZPRO

SRM450: STEREO OPERATION WITH A MIXER, AND USING THE THRU JACK

Daisy-chainingSRM450s

7

THRUOutput

DynamicMicrophone

SRM450: USING A MICROPHONE AND THE THRU JACK

yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy

yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy

PowerCord

PowerCord

PoleMount

PoleMount

Line-levelHi-pass

out

Line-levelHi-pass

out

FullRange

FullRange

PowerCords

PowerCords

SRS1500aplays the lowfrequencies

SRS1500aplays the lowfrequencies

1202-VLZPRO

SRM450: BIAMPING WITH A POWERED SUBWOOFER

The SRM450 can beused with a MackieSRS1500a Subwoofer tocreate an incrediblypowerful system.

The active crossoverinside the SRS1500asplits the full range in-put signal into tworanges. The SRS1500aplays the low frequencyrange through its 600watt amplifier and 15-inch woofer, and sendsthe high-pass range tothe SRM450.

The SRM450 can bepole mounted on top ofthe SRS1500a as shown,saving the cost of atripod stand.

For microphone connections, you candaisy-chain up to two SRM450s using theTHRU jacks as shown.

Take great care to point any micro-phones away from the SRM450s, otherwiseyou may get feedback.

8

REAR PANEL DESCRIPTION

TIMED TURNOFF

When this switch is pushed in, the built-in amplifiers turn on and off depending onthe presence or absence of an input signal.An input signal level of 45 dBu (mini-mum) activates the auto-on function. Asilent period greater than three minutesactivates the auto-off function. The blueLED on the front of the speaker reflects thestate of the amplifiers.

THERMAL Indicator

This LED lights if the heatsink tempera-ture exceeds a safe operating temperatureand triggers the thermal safety switch.When this occurs, the built-in amplifiersshut down until the heatsink temperaturecools back down. Then the thermal switchresets itself, the THERMAL indicator turnsoff, and normal operation resumes.

If the SRM450 keepsshutting down, makesure the PEAK light isnot lighting frequently orcontinuously, and that

there is plenty of ventilation to the rearpanel. Please see Thermal Considerationson page 12.

The SRM450 has several connectors,controls, and indicators that you shouldunderstand.

IEC SocketThis is where you connect the supplied

AC linecord to provide AC power to theSRM450s built-in power amplifiers. Plugthe linecord into an AC socket properlyconfigured for your particular model.

Note: If you happen to lose the AClinecord, replacements are readily availableat any office or computer supply store. Al-ways use a three-pin plug with a groundpin.

POWER SwitchSwitch up to turn the SRM450 on, and

switch down to turn it off. Make sure thelevel control is down before you turn it on.

POWER ON IndicatorWhen the POWER switch is turned on,

and the linecord is connected to an activeAC Mains supply, this indicator, locatedjust above the POWER switch, glows to letyou know that youre ready to rock androll. The cool blue LED on the front of thespeaker works in the same way.

9

CONTOURPushing in this switch engages a filter

that provides 3 dB of boost to the low andhigh frequencies (below 100Hz and above10kHz). This provides a punchy, crispsound for most live music applications. Youcan experiment with this switch by leavingit out for a while, then pushing it in to de-termine which way sounds best for yourapplication. It is especially useful when lis-tening at lower volumes, as it highlights thebass like a Loudness switch, in addition toboosting the highs.

LOW CUT

Pushing in this switch engages a low-cutfilter, which rolls off the low frequencies be-low 75Hz. This is useful for minimizingstage noise (rumble) and microphone han-dling noise.

LEVELThis controls the overall signal level at the

input to the built-in power amplifiers. Thiscontrol ranges from off up to 40 dB of gain.Since the SRM450 incorporates Mackiesworld-class low-noise mic preamp technol-ogy, you can connect either a line-level or amicrophone-level signal to the input.

There is no phantompower for a microphone,so you should use adynamic mic, or use acondensor type if it has

its own battery power.Follow the Quick Start guide for setting

the LEVEL control. For most applications,it will be in the NORMAL position (12oclock) . If you have a particularly highline-level signal connected to the SRM450,you may need to turn the control down tothe LINE indication (9 oclock). If you havea low line-level or mic-level signal con-nected, you may need to turn the LEVELcontrol up to the MIC indication(3 oclock).

SIGNAL PRESENT Indicator

This LED illuminates whenever there isa signal present at the INPUT connector onthe rear panel. It senses the signal just priorto the LEVEL control, so even if the LEVELcontrol is turned down, the SIGNALPRESENT indicator still works.

PEAK IndicatorWhen the signal levels at the amplifier

outputs approach clipping, a soft compres-sion circuit is activated that reduces theinput signal. The PEAK LED lights when-ever the compression circuit is active. Atthis time, the SRM450 may reach soundpressure levels of 120 dB or more.

Its okay for the PEAK indicator to blinkoccasionally, but if it blinks frequently orcontinuously, either turn down the signallevel at the mixer or other signal source, orturn down the SRM450s LEVEL control.

Wear hearing protectionif you are close to theSRM450 playing at highlevels.

INPUT Connector

This is a female XLR-type connector thataccepts a balanced or unbalanced mic- orline-level signal.

THRU Connector

This is a male XLR-type connector thatproduces exactly the same signal that isconnected to the INPUT jack. It can be abalanced or unbalanced mic- or line-levelsignal. Use it to daisy-chain several activemonitors together off the same signalsource.

ACCESSORY PlateThis removable plate provides access to

install future accessory modules. For fur-ther details of the module features andavailability, please check our website:www.mackie.com.

10

PLACEMENTThe SRM450 active monitors are de-

signed to sit on the floor, a tabletop, or to fiton a standard tripod speaker stand. Theycan also be suspended by the rigging points,shown opposite.

You can lay the cabinet down on its sideand use the SRM450 as a floor monitor. Theasymmetrical trapezoidal shape of the cabinetprovides a perfect angle for aiming up towardperformers from the front of the stage.

As with any poweredcomponents, protectthem from moisture. Ifyou are setting them upoutdoors, make sure they

are under cover if you expect rain.

The SRM450 generatesmagnetic fields. Do notplace them closer than 2or 3 feet (60-100 cm)from TV or computer

monitors. Check the screen for any changein color or distortion. Do not place anymagnetic audio or video tapes or computerdiscs near the SRM450s.

Room AcousticsThe SRM450 active monitors are de-

signed to sound as neutral as possible; thatis, to reproduce the input signal as accu-rately as possible, monitoring the soundrather than changing it.

Room acoustics play a crucial role in theoverall performance of a sound system.However, the wide high-frequency disper-sion of the SRM450 helps to minimize theproblems that typically arise.

Here are some other placement tips: Avoid placing loudspeakers in the

corners of a room. This increases thelow-frequency output and can cause thesound to be muddy and indistinct.

Balanced XLR Connectors

CONNECTIONSThe SRM450 has a female XLR input

that accepts a balanced or unbalanced mic-or line-level signal. When connecting a bal-anced signal, be sure its wired per AES(Audio Engineering Society) standards:

XLRHot (+) Pin 2Cold () Pin 3Shield (Ground) Pin 1

There is also a male XLR connector la-beled THRU. This allows you to connectmore than one SRM450 to the output ofyour mixing console. Simply plug the signalsource output into the first INPUT jack,and patch that speakers THRU jack to thenext INPUT jack, and so on, daisy-chainingmultiple speakers (see diagram on page 6).

There is a limit to howmany you can daisy-chaintogether. A general rule isto maintain a load imped-ance 10 times or more

than the source impedance to prevent ex-cessive loading on the source. For example,if your mixer has an output impedance of120 ohms, then you can daisy chain up tosixteen SRM450s. This is a load of 1250ohms (SRM450 input impedance=20kohms; 16 of these in parallel=1250 ohms).

Since microphones typically have ahigher output impedance, you should limitdaisy-chaining from a mic source to twoSRM450s (see the diagram on page 7).

The THRU jack is wired straight fromthe INPUT connector there is no elec-tronic circuitry between so the signalcoming out of the THRU jack is exactly thesame as the signal going in.

Top

900 Dispersionup to 18kHz

900

11

Avoid placing loudspeakers against a wall.This, too, increases the low frequencyoutput, though not as much as cornerplacement. However, if you do need toreinforce the low frequencies, this is agood way to do it.

Avoid placing the active monitors directlyon a hollow stage floor. A hollow stagecan resonate at certain frequencies,causing peaks and dips in the frequencyresponse of the room. Its better to placethe active monitors on a sturdy table ortripod stands.

Position the active monitors so the high-frequency drivers are 2 to 4 feet above earlevel for the audience (make allowancesfor a standing/dancing in the aislesaudience). High frequencies are highlydirectional and tend to be absorbed mucheasier than lower frequencies. By provid-ing direct line-of-sight from the activemonitors to the audience, you increase theoverall brightness and intelligibility of thesound system.

Highly reverberant rooms, like manygymnasiums and auditoriums, are anightmare for sound system intelligibility.Multiple reflections off the hard walls,ceiling, and floor play havoc with thesound. Depending on the situation, youmay be able to take some steps to mini-mize the reflections, such as puttingcarpeting on the floors, closing draperiesto cover large glass windows, or hangingtapestries or other materials on the wallsto absorb some of the sound.However, in most cases, these remediesare not possible or practical. So what doyou do? Making the sound system loudergenerally doesnt work because thereflections become louder, too. The bestapproach is to provide as much directsound coverage to the audience as pos-sible. The farther away you are from thespeaker, the more prominent will be thereflected sound.Use more speakers strategically placed sothey are closer to the back of the audience.If the distance between the front and backspeakers is more than about 100 feet, youshould use a delay processor to time-alignthe sound. (Since sound travels about 1foot per millisecond, it takes about 1/10 ofa second to travel 100 feet.)

SRM450

Rigging Points

Both SidesBack

BottomTop

PoleMount

RIGGINGThe SRM450 cabinets are fitted with rig-

ging points shown in the diagram below.

WARNING: Never at-tempt to suspend theSRM450 active monitorsby their handles. If youwant to suspend them,

use the rigging points only.Full details concerning rigging the

SRM450s can be found with MackiesCertified Rigging Accessories, includinghardware and information on safe workingloads. Contact your Mackie dealer or seeour website for details.

If you are hanging themin an inaccessable place,such as over a lions cage,make sure that you firstcomplete the sound check

and set the SRM450 LEVEL correctly. Alsoset the TIMED TURNOFF switch if youwant the SRM450 to turn on when there isa signal present. It will also turn off afterthree or more minutes of silence.

12

AC POWERCONSIDERATIONS

Be sure the SRM450 is plugged into anoutlet that is able to supply the correct volt-age specified for your model. If the voltageshould drop below 97% of the specified linevoltage, the built-in amplifiers will nolonger be able to supply rated power. (Theywill continue to operate down to 75% ofthe rated line voltage, but wont reach fullpower, resulting in lower headroom.)

Under maximum S.P.L. conditions,where musical peaks are clipping, theSRM450 120V model draws 2.5 amps onaverage (1.3 amps for the 240V model). Un-der normal conditions, the current draw isbelow 1 amp.

We recommend that a stiff (robust) sup-ply of AC power be used because theamplifiers place high current demands onthe AC line. The more power that is avail-able on the line, the louder the speakers willplay and the more peak output power willbe available for cleaner, punchier bass. Asuspected problem of poor bass perfor-mance is often caused by a weak ACsupply to the amplifiers.

AC Power Distribution

A 240VAC center-tapped service en-trance transformer serves the majority ofAC outlets encountered in homes and clubs(in the U.S.). This provides two phases ofAC power on either side of the center tap,at 120V each.

If lighting is used in a show, it is prefer-able to power the lights from one leg of theservice, and power the audio equipmentfrom the other leg. This will help minimizenoise from the lights coupling into the au-dio (particularly if SCRs, or light-dimmerswitches, are used).

TRANSFORMER

120V

120V

240V

HIGH VOLTAGE POWER LINE

EARTHGROUND

(NEUTRAL)

PRIMARYWINDING

SECONDARYWINDING

240V CENTER-TAPPED SECONDARY

THERMALCONSIDERATIONS

The SRM450 has two powerful amplifi-ers built-in. As amplifiers produce heat, it isimportant to dissipate the heat as quickly aspossible. This results in increased reliabilityand longevity for the amplifier. Thats whatthe massive die-cast aluminum heatsink onthe rear panel is for.

The heatsink is cooled by convection,where cool air is drawn through its fins,carrying the heat away. In order for thisconvection cooling to work efficiently, it isimportant to provide adequate airspace be-hind the loudspeaker. When you positionthe SRM450, we recommend leaving atleast six inches of air space behind it.

In the unlikely event of the amplifiersoverheating, a built-in thermal switch willactivate, placing the amplifiers into standby.The THERMAL indicator on the rear panellights, and the power LEDs on the frontand rear panel turn off. When the amplifi-ers have cooled down to a safe operatingtemperature, the thermal switch resets it-self, the power LEDs turn on, theTHERMAL LED turns off, and theSRM450 resumes normal operation.

Check to see if the PEAK LED on therear panel is blinking frequently or lightingcontinuously. If so, you should turn downthe LEVEL control a notch or two to avoidoverheating the amplifiers.

If the temperature in the room is toohigh, it could cause the amplifiers to over-heat. In this case, you should try aiming afan at the heatsink to move air through thefins faster.

HEATSINKTHERMAL PEAK

13

Wherever possible, connect all of yourequipment to the same electrical circuit.This will help reduce the possibility of aground loop problem causing an annoyinghum in your speakers.

Low power components such as tapedecks, mixers, effects processors and CDplayers should be connected to the sameoutlet as the SRM450s. Use fused powerstrips as shown in the diagram below. Makesure that the total current draw of yourcomponents does not exceed the capabilityof the outlets and power strips.

For the US 120 V model:A maximum of five SRM450s can be

connected per 15A service.This allows each SRM450 to be safely

operated at its maximum level.

When turning your system on, turn onthe SRM450s last. This will stop any turn-on thumps and bangs from your sourceequipment being amplified.

When turning off your system, turn offthe SRM450s first. This will prevent anyturn-off thumps and bangs from yoursource equipment being amplified.

SRM450 SRM450

When setting up for ashow, often you are plug-ging into an AC powerdistribution system youknow nothing about. You

may even be faced with 2-wire outlets thatare missing the third safety ground pin. Itsa good idea to have a three-wire AC outlettester in your toolbox so you can check theoutlets yourself to make sure they are wiredcorrectly. These testers will tell you if thepolarity of the hot and neutral wires is re-versed and if the safety ground isdisconnected.

Dont use an outlet if it iswired improperly! Thisis to protect yourself aswell as your equipment.

Never remove theground pin on the powercord of the SRM450 orany other component.This is very dangerous.

SRM450: AC CONNECTIONS

14

SERVICE INFORMATIONWarranty Service

Details concerning Warranty Service arespelled out on page 19 of this manual.

If you think your loudspeaker has aproblem, please do everything you can toconfirm it before calling for service, includ-ing reading through the followingTroubleshooting section. Doing so mightsave you from being deprived of yourMackie loudspeaker.

If you do find the prob-lem, make sure that youturn down the LEVELcontrols and turn off theSRM450 before correct-

ing it or changing any connections.Of all Mackie products returned for ser-

vice (which is hardly any at all), many arecoded CND Could Not Duplicatewhich usually means the problem lay some-where else in the system. The followingtroubleshooting tips may sound obvious,but here are some things you can check:

Troubleshooting

No power! Our favorite question: Is it plugged in?

Make sure the AC outlet is live (checkwith a tester or lamp).

Our next favorite question: Is thePOWER switch on? If not, try turningit on.

Is the blue light on the front panelilluminated? If not, make sure the ACoutlet is live. If so, refer to No soundbelow.

The AC line fuse inside the chassis isblown. This is not a user-serviceablepart. Refer to Repair on page 16 tofind out how to proceed.

No sound! Is the input LEVEL control turned all

the way down? Follow the proceduresin the Quick Start section on page 6to verify that all the volume controls inthe system are properly adjusted.

Is the signal source working (and makingunion scale)? Make sure the connectingcables are in good repair and securely

connected at both ends. Make sure theoutput volume (gain) control on themixing console or preamp is turned upsufficiently to drive the inputs of thespeaker. You should be able to see theSIGNAL PRESENT LED blink on therear panel.

Make sure the preamp or mixer doesnot have a Mute on, or a Tape orProcessor loop engaged. If you findsomething like this, make sure thevolume/gain is turned down beforedisengaging the offending switch.

Is the THERMAL LED lit? Make sure thereis at least six inches of free space behindthe heatsinks. Allow the SRM450 to cooloff and it will turn back on.

One side is way louder than the other! Are the LEVEL controls set the same on

both active monitors? Check the PAN control or balance on

the signal source. It may be turned toofar to one side. If youre using a stereosignal source, it may be delivering anout-of-balance stereo signal.

Try swapping sides: Turn off the activemonitors, swap the input cables comingfrom the mixing console, turn the activemonitors back on. If the same side isstill louder, the problem may be withyour active monitors or cables betweenthe mixer and the active monitor. If theother side is louder now, the problem iswith the mixer or the signal source.

Poor bass performance

Check the polarity of the connectionsbetween the mixer/preamp and theactive monitors. You may have yourpositive and negative connectionsreversed at one end of one cable, causingone SRM450 to be out-of-phase.

As soon as the music gets loud, theSRM450 shuts down!

Be sure that the PEAK LED on the rearpanel is not lighting up frequently orcontinuously.

Remember to wear earprotectors if you get closeto an SRM450 playing athigh levels. When thePEAK LED comes on,

the SPL is in the region of 120 dB!!!

15

Make sure there is room behind the rearpanel to provide sufficient ventilation tothe heatsink.

Bad sound! Is it loud and distorted? Follow the

procedures described in the QuickStart section to verify that the levelsare set properly.

Is the input connector plugged com-pletely into the jack? Be sure allconnections are secure. Its a good ideato periodically clean all electricalconnections with a non-lubricatingelectrical contact cleaner.

Noise Make sure all connections to the active

monitors are good and sound. Make sure none of the signal cables are

routed near AC cables, power trans-formers, or other EMI-inducing devices.

Is there a light dimmer or other SCR-based device on the same AC circuit asthe SRM450? Use an AC line filter orplug the SRM450 into a different ACcircuit.

Hum Turn the LEVEL control all the way

down. If the noise disappears, itscoming from the signal source. If not,try disconnecting the cable connected tothe INPUT jack. If the noise disappears,it could be a ground loop, rather thana problem with the SRM450. Try someof the following troubleshooting ideas:

Use balanced connections throughoutyour system for the best noise rejection.

Whenever possible, plug all the audioequipments linecords into outlets whichshare a common ground (see the dia-gram on page 13). The distance betweenthe outlets and the common groundshould be as short as possible.

Never remove theground pin on the powercord of the SRM450 orany other component.This is very dangerous.

The hum may appear when using anunbalanced source (consumer preamp,CD player, VCR, etc.). This is caused bythe unbalanced-to-balanced interface

shield

123

XLRRCA3-Conductor Cable

between the devices (and exacerbatedby the fact that most consumer audioequipment have a two-wire linecord,without the third-pin safety ground).Use an interconnect cable wired asshown below. The important point isthat the shield and the wire from theXLR pin 3 are joined at the RCA(source) end.

Disconnect any cables which come infrom outside, such as cable TV, satelliteTV or roof top antennas. They must bedisconnected from every part of yoursystem, such as the TV, VCR andpreamp. If the hum goes away, you canadd a ground loop isolator in yourcable line. This is an inexpensive deviceavailable from video or TV dealers, oryou can make your own from two TVbaluns (standard TV 75/300 ohmadaptors):

The baluns are threaded at one end(75 ohm) to fit TV coax cable and havetwo wires at the other end (300 ohm).They will not affect the video quality.

If the hum persists, try removing compo-nents one at a time from the back of themixer or preamplifier, and check for humeach time (turn off your equipmentbefore you undo any connections). It isfairly common to find more than oneproblem.

If your preamp or mixer are the onlythings connected to the SRM450s andthe hum is still there, try differentconnection cables, or move the preamp/mixer to another location.

Pressing the LOW CUT FILTER mayhelp reduce the hum if you have troublefinding the cause of the problem. Do thisanyway if you do not need to reproducethe lower frequency range.

join (+insulate) BalunBalun

16

REPAIRService for the SRM450 is available only

from one of our authorized domestic ser-vice stations or at the factory, located insunny Woodinville, Washington. Serviceoutside the United States can be obtainedthrough local dealers or distributors.

If your SRM450 needs service, please fol-low these instructions:1. Review the preceding troubleshooting

suggestions. Please.2. Call Tech Support at 1-800-258-6883,

8am to 5pm PST, to explain the problemin detail. They will ask you all sorts ofimpertinent questions in the hope ofsorting out the problem. If it appearsthat the SRM450 needs repair, requestan RA (Return Authorization) number.Have your monitors serial numberready. You must have an RA numberbefore you can obtain service at thefactory or an authorized service center.

3. Keep this owners manual. We dontneed it to repair the active monitor.

4. Pack the loud-speaker in its originalpackage, includingprotective wrap, endcaps,and box. This is very

important. When you call for the RAnumber, please let Tech Support knowif you need new packaging. Mackie isnot responsible for any damage thatoccurs due to non-factory packaging.

5. Include a legible note stating your name,shipping address (no P.O. boxes),daytime phone number, RA number,and a detailed description of the prob-lem, including how we can duplicate it.

6. Write the RA number in BIG PRINTon top of the box.

7. Ship the active monitor to us. Werecommend United Parcel Service(UPS). We suggest insurance for allforms of cartage. Ship to this address:

Mackie DesignsSERVICE DEPARTMENT16220 Wood-Red Rd. NEWoodinville, WA 98072

8. Well try to fix the monitor within threebusiness days. Ask Tech Support for thelatest turnaround times when you callfor your RA number. We normally sendeverything back prepaid using UPSBLUE (Second Day Air). However, ifyou rush your monitor to us by NextDay Air, well treat it in kind by ship-ping it back to you UPS RED (Next DayAir). This paragraph does not necessar-ily apply to non-warranty service.

CARE ANDMAINTENANCE

Your Mackie active monitors will pro-vide many years of reliable service if youfollow these guidelines:

Avoid exposing theactive monitors tomoisture. If they are setup outdoors, be sure theyare under cover if you

expect rain. Avoid exposure to extreme cold (below

freezing temperatures). If you mustoperate the active monitors in a coldenvironment, warm up the voice coilsslowly by sending a low-level signalthrough them for about 15 minutesprior to high-power operation.

Use a slighty damp cloth with a mildsoap solution to clean the cabinets. Onlydo this when the power is turned off.Avoid getting moisture into any of theopenings of the cabinet, particularlywhere the drivers are located.

17

SPECIFICATIONS

Transducer SpecificationsLow-Frequency Transducer

Diameter 300mm (12)Voice Coil Diameter 63.5mm (2.5)Sensitivity (1W@1m) 98 dBNominal Impedance 8 ohmsPower Handling 300 wattsFrequency Range 55Hz 3000Hz

High-Frequency Driver and Horn

Diaphragm Diameter 44.5mm (1.75)Exit Throat Diameter 24.5mm (1)Diaphragm Material TitaniumSensitivity (1W@1m) 106 dBNominal Impedance 8 ohmsPower Handling 100 wattsFrequency Range 1000Hz 20,000HzHorn Type

Composite: Exponential and ConicalMouth Size

304.8mm (12) W x 177.8mm (7) HHorizontal Coverage

90 10 (1kHz 20kHz)Vertical Coverage

45 10 (2.8kHz 20kHz)

Power Amplifier and SystemSpecificationsLow-Frequency Power Amplifier

Rated Power 300 wattsRated THD < 0.03%Cooling Convection ExtrusionDesign Class G, Parametric Servo Feedback

High-Frequency Power Amplifier

Rated Power 100 wattsRated THD < 0.03%Cooling Convection ExtrusionDesign Conventional Class AB

System SpecificationsInput Type Balanced DifferentialInput Impedance

Line: 20k ohmsInput Protection RFI and level protectedSensitivity

Line: +4 dBu (center detent)Mic: 36 dBu

Maximum Input LevelLine: +22 dBu

Low-Cut Frequency100Hz, Second-order filter

Acoustic Contour EqualizationPeaking: +3 dB @ 100Hz,

+3 dB @ 12kHzEnclosure Alignment Sixth-OrderOver-Excursion Protection

Second-Order High-Pass FilterThermal Protection Amplifier shutdown,

auto-reset

Low-Line Voltage Shut Down60% Nominal line

Acoustic Frequency Response45Hz 20,000Hz

Low-Freq 3 dB Point 55HzMaximum SPL @ 1m 123 dBLow-Freq Crossover 24 dB/octave,

time offset correctedHigh-Freq Crossover 24 dB/octaveCrossover Frequency 1600HzDriver Protection Independent LF and

HF compressorsLow-Freq Roll-Off Dynamic-signal level

dependentAccessory Interface 15V DC,

normalized signal I/OOperating Temperature Range

10C to 45C(14F to 113F)

Line Input PowerUS 120V, 60HzEurope 230V, 50HzJapan 100V, 50/60Hz

Physical PropertiesHeight 660mm (25.98)Width 390mm (15.35)Depth 376mm (14.8)Weight 23.2kg (51 lbs.)Enclosure Geometry Asymmetrical TrapezoidalMounting Methods Integrated mounting points, M10 Two each located on each side, top, bottom, and rear of enclosure

DisclaimerSince we are always striving to

make our products better by incor-porating new and improvedmaterials, components, and manu-facturing methods, we reserve theright to change these specificationsat any time without notice.

Mackie, the Running Man figure, andFR Series are trademarks or registered trademarksof Mackie Designs Inc.

All other brand names mentioned are trade-marks or registered trademarks of their respectiveholders, and are hereby acknowledged.

1999 Mackie Designs Inc.All Rights Reserved.Printed in the U.S.A.

14.8"-376mm

25.98"-660mm

14.8"-376mm

15.35"-390mm

15.35"-390mm

18

SRM450 BLOCK DIAGRAM

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19

A. Mackie warrants all materials, workmanship andproper operation of this SRM450 for a period of oneyear from the original date of purchase. If youcomplete the optional questionnaire portion of theProduct Registration Card, the warranty will beextended for an additional FOUR years with thefollowing exception: warranty on all its loudspeakercomponents including woofers and compressiondrivers are only warranted for an additional one year(for a total of two years). If any defects are found inthe materials or workmanship or if the product failsto function properly during the applicable warrantyperiod, Mackie, at its option, will repair or replacethe product. This warranty applies only to equip-ment sold and delivered within the U.S. by Mackieor its authorized dealers.B. Failure to return the card will not void the 1-yearwarranty.C. Service and repairs of Mackie products are to beperformed only at the factory (see D below) OR at anAuthorized Mackie Service Center (see E below).Unauthorized service, repairs, or modification willvoid this warranty.D. To obtain factory service:

1. Call Mackie at 800/258-6883, 8AM to 5PMMonday through Friday (Pacific Time) to get aReturn Authorization (RA). Products returnedwithout an RA number will be refused.2. Pack the SRM450 in its original shippingcarton. If you do not have the carton, just ask forone when you get your RA number, and wellsend a shipping carton out promptly. Moreinformation on packing can be found in theService section of this manual. Also include anote explaining exactly how to duplicate theproblem, a copy of the sales receipt with priceand date showing, and your return street address(no P.O. boxes or route numbers, please!). If wecannot duplicate the problem at the MackieFactory or establish the starting date of yourLimited Warranty, we may, at our option, chargefor service time.3. Ship the product in its original shippingcarton, freight prepaid to:

Mackie Designs Inc.SERVICE DEPARTMENT

16220 Wood-Red Road NEWoodinville, WA, 98072, USA

IMPORTANT: Make sure that the RA number isplainly written on the shipping carton.E. To obtain service from an Authorized Mackie ServiceCenter:

1. Call Mackie at 800/258-6883, 8AM to 5PMMonday through Friday (Pacific Time) to get: 1) The name and address of your nearest MackieAuthorized Service Center and 2) A returnauthorization (RA). You must have an RA numberbefore taking your unit to a service center.2. Make sure that you have a copy of your activemonitors sales receipt from the store where youbought the product. It is necessary to establishpurchase date and thus determine whether or notyour active monitor is still under warranty. If youcan't find it, the Authorized Service Center maycharge you for repairs even if your active monitor isstill covered by Mackie's 1-Year Limited Warranty.

3. Make sure that the problem can be dupli-cated. If you bring your active monitor to anAuthorized Service Center and they can't findanything wrong with it, you may be charged aservice fee.4. If the Mackie Authorized Service Center islocated in another city, pack the active monitorin its original shipping carton. More informationon packing can be found in the Service section ofthis manual.5. Contact the Mackie Authorized Service Center toarrange service or bring the active monitor to them.

F. Mackie and Mackie Authorized Service Centersreserve the right to inspect any products that maybe the subject of any warranty claims before repairor replacement is carried out. Mackie and MackieAuthorized Service Centers may, at their option,require proof of the original date of purchase in theform of a dated copy of the original dealers invoiceor sales receipt. Final determination of warrantycoverage lies solely with Mackie Designs Inc. or itsAuthorized Service Centers.G. Mackie active monitors returned to Mackie anddeemed eligible for repair or replacement under theterms of this warranty will be repaired or replacedwithin thirty days of receipt by Mackie at ourrainforest factory complex. Products returned toMackie that do not meet the terms of this Warrantywill be repaired and returned C.O.D. with billingfor labor, materials, return freight, and insurance.Products repaired under warranty at Mackie'sfactory will be returned freight prepaid by Mackieto any location within the boundaries of the USA.H. Mackie assumes no responsibility for the qualityor timeliness of repairs performed by MackieAuthorized Service Centers.I. This warranty is extended to the originalpurchaser and to anyone who may subsequentlypurchase this product within the applicablewarranty period.J. This is your sole warranty. Mackie does notauthorize any third party, including any dealer orsales representative, to assume any liability onbehalf of Mackie Designs or to make any warrantyfor Mackie Designs.K. THE WARRANTY GIVEN ON THIS PAGE IS THESOLE WARRANTY GIVEN BY MACKIE AND IS INLIEU OF ALL OTHER WARRANTIES, EXPRESSAND IMPLIED, INCLUDING THE WARRANTIESOF MERCHANTABILITY AND FITNESS FOR APARTICULAR PURPOSE. THE WARRANTY GIVENON THIS PAGE SHALL BE STRICTLY LIMITED INDURATION TO ONE YEAR FROM THE DATE OFORIGINAL PURCHASE FROM AN AUTHORIZEDMACKIE DEALER. UPON EXPIRATION OF THEAPPLICABLE WARRANTY PERIOD, MACKIESHALL HAVE NO FURTHER WARRANTY OBLIGA-TION OF ANY KIND. MACKIE SHALL NOT BELIABLE FOR ANY INCIDENTAL, SPECIAL, ORCONSEQUENTIAL DAMAGES THAT MAY RESULTFROM ANY DEFECT IN THE MACKIE PRODUCTOR ANY WARRANTY CLAIM. Some states do notallow exclusion or limitation of incidental, special,or consequential damages or a limitation on howlong warranties last, so some of the above limita-tions and exclusions may not apply to you. Thiswarranty provides specific legal rights and you mayhave other rights which vary from state to state.

Please keep your sales receipt in a safe place.SRM450 LIMITED WARRANTY