Step 1: Insert key to unlock front panel and adjust VU meter preset until the peaks of the incoming audio illuminate the red endstop 0dB LEDs.

Step 2: Adjust max output level preset until sound system volume reaches the maximum permitted SPL as specified by the installer or client. Remove key . . . and sleep soundly.

The Drawmer SP2120 Speaker Protector offers both strict level control and tremendous peace of mind to the contractor, installer and venue in the knowledge that only the maintenance engineer and the venue manager hold a key. As its name suggests the 1U, two channel processor eliminates the possibility of 'unauthorized' excessive sound pressure levels on speaker systems which could result in damage to both chassis drivers and amplifier electronics. The unit also gives a wide variety of venues, such as clubs, theaters, pubs, schools, universities etc. the opportunity to comply with the local legislation regarding noise levels.

The SP2120 front panel features an integral security lock to ensure that adjustments to maximum volume levels are implemented by key holders only. In 'unlocked' mode two front panel presets are exposed and available for adjustment by the installer. The first calibrates the 16 segment Left/Right bargraphs to the incoming audio and dictates the point at which 'protection' processing commences. The second sets the absolute volume level to which the sound system is allowed to perform. If the SP2120 receives increased signal levels, the transparent 'protection' circuitry is activated which maintains the specified system volume level without degradation in sound quality.

The SP2120 greatly benefits from Drawmer's 25 years experience in designing industry standard dynamic processing devices. Its signal path combines a mixture of 'multiple time constant' circuitry and automatic gain control (AGC) which allow small overloads to sound louder - even though they're not. Its concept and development was encouraged by Drawmer distributors and installers dissatisfied with other protection systems currently available. These often take the form of a crude switch, either turning off the power or disconnecting the speakers, both of which are 'disruptive' in any event.

The SP2120 is intended to be inserted in the sound system immediately prior to the amplifier stage.