4 Input Mixer With Fire Muting

Many large commercial buildings these days employ two PA systems. One is the traditional PA/BGM system for every day paging and music distribution. The second is a stand alone emergency evacuation PA system for use in the event of a fire or other emergency. This mixer has been designed for such installations.

It works as a stand alone audio processor with four mic/line inputs for microphone and music sources. Plus it has a set of contacts connected to the buildings Fire Indicator Board (FIB). When the FIB operates it triggers these contacts, rending the local PA/BGM system inoperative so the main emergency evacuation system has precedence.

All inputs can be configured for either balanced mic via 3 pin XLR or line inputs via RCA. Line input sensitivity is adjustable from 100mV to 1V using rear mounted DIP switches. Phantom power is also available on all inputs. Outputs are either balanced 3 pin XLR or stereo RCA connectors.

Individual & master level controls are provided on the front panel along with recessed treble and bass adjustments.

Provision is included for the A4573 alert/evac module which  generates pre chime, bell, alert and evacuation tones.  The alert tone can function continuously, or switch to evac tone after a preset time delay (adjustable 30 seconds to 4.5 minutes).  Simply connects to the mixer internally via the cable provided.

Features

4 mic or line inputs
Balanced line or RCA outputs
VOX priority on input 1 and 2
Phantom power ON/OFF for mic inputs
Remote evacuation system muting contacts
24V DC operation
Individual volume, treble and bass for all inputs
Provision for A4573 alert evac tone generator module

Specifications:
Audio
Inputs: 4 x mic balanced 600Ω, 4 x Line Stereo 10KΩ
Output (stereo): 600Ω balanced 0dBm
Distortion: Less than 0.3%
Frequency Response Mic: 30Hz-15kHz
Frequency Response Line: 18Hz-23kHz
S/N ratio: All controls min. -98dB
Sensitivity: Mic 2mV, line 100mV/1V
Phantom power: Nominal 12V DC
Output connectors: 3 pin XLR balanced, Stereo RCA

Controls
Mic/line inputs: Bass, treble & volume + master
Bass/Treble: ±10dB @ 100Hz
Vox Sensitivity: Adjustable on front panel.

Input Connectors
Mic inputs: 3 pin XLR balanced
Line inputs: RCA sockets
Indicators: Output active, power
Muting trigger: Screw terminal blocks

General
Power supply: 24V DC
Dimensions: 482W x 175D x 44H mm
Weight: ≈2kg