THERMAL CONSIDERATIONS AC POWER CONSIDERATIONS

The amplifiers inside the SRM450v2s are convection cooled by a large heatsink. For efficient cooling, it is important to allow at least six inches of free space behind the SRM450v2.

If you use the SRM450v2 on its side for stage monitor applications, we highly recommended that you engage the rear panel LOW CUT switch. This will allow more power for useful monitor frequencies, while reducing the possibility of overheating.

Be sure the SRM450v2 is plugged into an outlet that is able to supply the correct voltage specified for your model. If the voltage should drop below 97% of the specified line voltage, the built-in amplifiers will no longer be able to supply rated power. (They will continue to operate down to 75% of the rated line voltage, but won’t reach full power, resulting in lower headroom).

Under maximum SPL conditions, where musical peaks are clipping, the SRM450v2 120V model draws 2.5 amps on average (1.3 amps for the 240V model). Under normal conditions, the current draw is below 1 amp.

We recommend that a stiff (robust) supply of AC power be used because the amplifiers 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 cleaner, punchier bass. A suspected problem of “poor bass performance” is often caused by a weak AC supply to the amplifiers.

If the ambient temperature in the room is high, though highly unlikely, it could cause the amplifiers to overheat. In this case, you should try aiming a fan at the heatsink to increase the air flow through the fins.

During a performance, don’t have it cranked so high that the rear panel PEAK LED is blinking frequently or lighting continuously. You should turn down the LEVEL control a notch or two to avoid overheating the amplifiers or your neighbors.

If the amplifiers do overheat, a built-in thermal switch will activate, placing the amplifiers into standby. When the amplifiers have cooled down to a safe operating temperature, the thermal switch will reset and the SRM450v2 will resume normal operation.

AC Power Distribution

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

If lighting is used in a show, it is preferable to power

the lights from one leg of the service, and power the audio equipment from the other leg. This will help minimize noise from the lights coupling into the audio (particularly if SCRs, or light-dimmer switches, are used).

Wherever possible, connect all of your equipment to the same electrical circuit. This will help reduce the possibility of a ground loop problem causing an annoying hum in your speakers.

HEATSINK

LOW CUT

Low power components such as tape decks, mixers, effects processors and CD players should be connected to the same outlet as the SRM450v2s. Use fused power strips as shown in the diagram on the next page. Make sure that the total current draw of your components does not exceed the capability of the outlets and power strips.

THERMAL

THERMAL

HIGH VOLTAGE POWER LINE

PEAK

PEAK SIGNAL PRESENT

NORMAL

(+4dBu)

ON

POWER

LINE

MIC

OFF

TIMED TURNOFF

100Hz

12k/AIR

ON

CONTOUR +3dB

12

75Hz

OO +40dB

120V

 

LOW CUT

 

LEVEL

 

 

PRIMARY

240V

SECONDARY

 

WINDING

WINDING

 

 

THRU

INPUT

120V

 

PARALLEL

 

 

 

 

TRANSFORMER

EARTH

 

 

 

GROUND

 

 

 

(NEUTRAL)

 

240V CENTER-TAPPED SECONDARY