Designed to provide for additional supervised audio power for live voice, pre-recorded messages or background music (BGM). Fully supervised patent pending circuitry is always in effect even during BGM. The SPB-80/4 also provides 4 Amps of 24 VDC Supervised and Synchronized Strobe Power. The SPB-320, SPB-160 and the SPB- 80/4 easily connects to the Wheelock SP40S or SP40/2. Multiple SPB- 320, SPB-160 and SPB-80/4 Audio Boosters can be inter-connected to accommodate large installations with supervised audio power and also supervised and synchronized strobe power requirements.