When a hotel's fire panel activates, it sends a dry-contact or relay signal to the AV/control system, which mutes background music, ballroom audio, and video walls so the voice evacuation message is the only thing anyone hears. This is handled as a defined interface between two separate trades — the fire alarm contractor and the AV/control integrator — not as a single system doing double duty. Getting it right means agreeing on the signal type, what the control processor does when it sees that signal, and how the house recovers once the alarm resets. Below is what that interface actually involves and what should be tested together before an inspector signs off.
What signal does the fire panel actually send to AV?
The fire alarm contractor's panel closes or opens a dedicated relay contact when the system goes into alarm, and that dry contact is wired into the AV or control system as an input. On the Crestron Home platform, this input is handled through the security system device's Interrupts settings, which are specifically built to react to connected alarm events, including a defined Smoke Alarm event type that is enabled by default. The interrupt config lets the integrator set a Mute Whole House option, which silences audio playing in any media room for a configurable duration, with a default window of five seconds (Interrupt Settings | Crestron Home OS Documentation). In a hotel context, this is the same mechanism a control processor uses to decide: fire panel says alarm, audio paths go silent.
It is worth distinguishing this general-purpose mute-on-alarm logic from a true life-safety voice evacuation system. As AVIXA notes, Voice Alarm (Evacuation) systems are a distinct category from Public Address systems: they are built specifically for emergencies, are typically integrated directly with fire detection for automated response, meet stringent reliability and intelligibility standards such as EN 54, and their emergency messages override all other communications on the system (Public Address vs. Voice Alarm (Evac) Systems: Understanding the Differences | AVIXA). A hotel's background-music and ballroom AV system is not the voice evacuation system itself — it is the thing that has to get out of the way so the voice evacuation message is intelligible. Ask your fire alarm contractor and your AV integrator, up front, which system is actually carrying the evacuation message, and confirm the background-music/ballroom AV only needs to mute, not to announce.
How does a Crestron or DSP system act on that signal?
Once the fire-panel contact reaches the control system, the response is configured at the interrupt or event level rather than left to interpretation during an actual alarm. On Crestron Home, each monitored device and event combination — including a security system's fire event — has its own enable/disable setting, a custom or default on-screen message, a "Bypass Do Not Disturb" option so the alert overrides any room set to quiet mode, and the Mute Whole House toggle with its own duration field (Interrupt Settings | Crestron Home OS Documentation). For a hotel ballroom or public-space system, the practical decision during design is whether the fire input should simply mute currently playing audio at the DSP/matrix level, or whether it should trigger a harder power-sequencer shutdown of amplifiers and displays. That decision belongs in the commissioning documentation, not assumed from either trade's default behavior — ask your integrator which approach the system was configured to use room by room, and why.
On the video side, the CEDIA guidance on integrated fire/smoke systems confirms the same category of response extends to displays: a connected system can be configured to display an alert visually on TV monitors in addition to muting audio and triggering lighting and speaker announcements (Smart Fire Detectors & Smart Home Fire Alarms for Safety | CEDIA). Applied to a lobby or ballroom video wall, that means the control system's fire-alarm response should also define what the screens do — go black, show a static alert graphic, or simply stop routing active content — as part of the same interrupt logic that mutes the audio, coordinated through Crestron DM NVX distribution. (For more on sizing and content planning for that kind of display, see the lobby video wall guide.)
What happens to ballroom audio and video walls specifically?
In a ballroom or banquet space running Crestron Flex or a similar AV-over-IP system, the fire-alarm mute needs to reach every active audio zone in that room — house music, paging, and any live program feed from a stage or lectern — not just a single default zone. The Mute Whole House behavior described in Crestron's documentation is built to act across "any media room" rather than a single device, which is the relevant model for a multi-zone banquet floor (Interrupt Settings | Crestron Home OS Documentation). Confirm with your integrator that every zone on the DSP — including any that are normally controlled independently by catering or AV staff during an event — is wired into the same fire-interrupt logic, and is not exempt because it is "managed manually" that night.
Video walls present a separate question: whether the fire signal should simply stop routing content to the wall, or power the displays down entirely. A hard power-sequencer shutdown adds recovery time after the alarm resets, while a mute-and-black approach recovers faster but keeps displays powered. Neither approach is inherently correct for every property — it depends on the fire marshal's requirements and the property's recovery-time expectations, and it is a question to put directly to the fire alarm contractor and AV integrator jointly during design, not decided unilaterally by either trade.
Who owns each side of the fire-to-AV interface?
The fire alarm contractor owns the panel, the relay or dry-contact output, the wiring to that output, and the life-safety voice evacuation system itself when one is present — all of which typically fall under code-driven licensing and inspection requirements that sit outside AV scope. The AV/control integrator owns everything downstream of that contact: the input wiring into the control processor, the interrupt configuration (which events are enabled, which rooms are affected, mute duration, Do Not Disturb bypass), and the DSP or power-sequencer logic that actually silences program audio and clears video walls. Cave Group, as a Crestron Elite Gold Partner and Lutron HTI-certified hospitality integrator, designs and programs that downstream side of the interface as part of its hospitality guest-room and public-space AV scope, working alongside whichever licensed fire alarm contractor the project requires. Neither trade should assume the other has closed the loop — the interface only works if both sides document the signal, the response, and who tests it.
How does the system recover after the alarm resets?
Recovery behavior should be defined with the same specificity as the alarm-trigger behavior: does audio resume automatically once the fire panel clears, or does it require a manual restart from staff or the AV integrator's remote support tools? Crestron's interrupt configuration ties mute duration to a fixed, configurable window rather than an open-ended state, which argues for documenting exactly how long audio stays muted and what, if anything, auto-resumes versus requires a manual cue. For ballroom and public-space systems, confirm whether the DSP returns zones to their pre-alarm volume and source automatically or whether staff need to manually re-engage each zone — and make sure that answer is written into the commissioning documentation your integrator hands over, not left to be rediscovered during the next real event.
What should both trades test together before opening?
Before a hospitality property opens, or reopens after a renovation, the fire alarm contractor and AV/control integrator should run a joint acceptance test rather than validating each side of the interface independently. That test should confirm: the fire panel's relay or dry contact actually reaches the control processor's input; every configured interrupt event (not just the first one tested) correctly triggers mute, Do Not Disturb bypass, and any on-screen alert message; every audio zone in every public and ballroom space actually goes silent, not just a default or demo zone; video walls and displays behave as specified, whether that is going dark or clearing content; and the system recovers in the documented way once the panel resets. This joint test belongs on the same punch list as PMS, access, and network acceptance testing before a property opens, and it should be re-run after any AV, DSP, or control-processor firmware change that touches the interrupt configuration.
Frequently asked questions
Does the fire alarm system itself carry the evacuation announcement?
Not always. A Voice Alarm (Evacuation) system is a distinct, code-regulated system built specifically for emergency messaging and typically integrates directly with fire detection, separate from a property's everyday Public Address or background-music system, which may simply need to mute rather than announce.
What does "Mute Whole House" actually do on a Crestron system?
On Crestron Home, Mute Whole House is an interrupt setting that silences audio playing in any media room for a configurable duration, with a five-second default, triggered by an enabled event such as a connected fire or smoke alarm.
Can the fire-alarm mute override a room set to Do Not Disturb?
Yes. Crestron's interrupt configuration includes a "Bypass Do Not Disturb" option specifically so a life-safety alert can still play its chime and message even in a room set to quiet mode.
Who is responsible for wiring the fire panel into the AV system?
The fire alarm contractor owns the panel and its relay or dry-contact output; the AV/control integrator owns the wiring and programming from that contact into the control processor and downstream to audio zones and displays. Both scopes should be documented and jointly tested.
What happens to video walls when the fire alarm activates?
A configured system can be set to display an alert on connected monitors in addition to muting audio, but whether a video wall goes dark, shows a static message, or simply stops routing content is a design decision that should be settled with the fire alarm contractor and AV integrator before opening.