Specifications

A clipping LED indicator is located on the rear panel. This LED will illuminate

when the speaker is several dB into limiting and indicates maximum operat-

ing level has been reached. It is not uncommon to see the LED illuminate reg-

ularly, such as on downbeats and crescendos.

If the LED appears to be "ON" more than "OFF" (i.e., if they are continuously

flashing or glowing at a steady state), the loudspeaker system is being pushed

too hard for its size and power output capability. To correct this, reduce the

drive level to the speaker system, or install additional speakers to achieve the

SPL (Sound Pressure Level) required for the application.

(3) A Word About Limiters

Properly designed protective limiters can do wonders to help prevent driv-

er damage and extend normal driver life, but are by no means a panacea.

Apogee limiters do not exhibit “brick-wall” characteristics, as these type of

limiters seriously degrade sound quality. Apogee’s intelligently engineered

limiter circuits provide an excellent measure of protection, while maintaining

sonic purity.

These limiter circuits are capable of effectively reducing program levels that

would otherwise damage the system’s drivers. This takes place with little or

no loss of sonic quality or dynamic range, because the circuits are designed

so that they only engage when driver non-linearity or driver damage would

otherwise occur. However, when a limiter is pushed well past its threshold of

engagement to the point where it is continually “in circuit”, by nature, it

increases the duty-cycle of the program material. This happens because, as

the limiter decreases peak amplitudes, RMS values increase, causing the driv-

ers to heat beyond normal. Additional circuits could be employed to reduce

levels and “clamp” the output of the system, but such circuits would repre-

sent a high level of intervention and be very audible in their action. The prop-

er solution is for the operator to recognize that the system is being pushed

past its capabilities and either reduce operating levels or add additional

speaker systems to provide the desired Sound Pressure Level (SPL).