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 pre-sets 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.