The Guardian CX4 MK3 handles two jobs a licensed venue's sound system usually needs: getting announcements over the music when the fire alarm goes, and keeping the music under a maximum level the rest of the time. When its trigger input fires, programme audio on 4 mono or 2 stereo channels is turned down and a priority microphone or line source is mixed in; reset can be automatic or manual. Separately, each of two stereo channels has a slow average limiter and a fast peak limiter, with a security loop that drops the limit further if broken.
4 mono / 2 st
Priority channels
0 to -60 dB
Programme duck
Avg + peak
Limiters · 2 stereo
1U
Rack · 19 inch
Trigger optionsThe trigger input accepts voltage applied, voltage removed, normally-open or normally-closed contacts, so it will interface with most fire alarm panels. Connection to a fire alarm system should be agreed with the fire alarm installer.
Features
Priority override on 4 mono or 2 stereo channels from a fire alarm or other trigger
Programme attenuated 0 to -60 dB on trigger (factory -20 dB)
Priority input switchable mic (up to 70 dB gain, 18 V phantom) or line
Priority input passes through when idle, so the DJ or MC mic can double as the priority mic
Automatic or manual reset, with test and reset buttons on the front panel
Sound level control on 2 stereo channels: slow average limiter plus fast peak limiter
Security loop per channel pair drops the limit by a preset dim amount if broken
LED indicators and remote LED outputs
Specifications
| Type | Priority / fire alarm interface with sound level control |
| Priority channels | 4 mono or 2 stereo; attenuation 0 to -60 dB |
| Trigger input | Voltage applied or removed, NO or NC contacts; under 10 mA |
| Level control | 2 stereo channels, average limiter (threshold -20 to +22 dBu) plus peak limiter |
| Audio connectors | XLR, balanced |
| Maximum level | +22 dBu in and out (600 Ohm) |
| THD | Below 0.015% at +20 dBu |
| Noise (EIN) | Below -90 dBu |
| Priority input | Mic (70 dB max gain, 18 V phantom by jumper) or line (+30 dBu max) |
| Control connections | 2 x 6-way screw terminal blocks |
| Power | 220-240 V or 110-120 V AC (switch), IEC inlet |
| Size | 1U, 482 mm wide, approx. 200 mm deep |
| Part number | 051 |





