Divisible Room AV Combining with Partition Sensors

A divisible room combines correctly when one control processor owns the combine state, reads it from hard-wired partition sensors, and pushes that state to the DSP, video matrix and touch panels in a fixed order. Most combining faults come from two systems each holding their own idea of which walls are open, not from the equipment itself.

This integration note is written by Singapore-based AV and IPTV integrator Prestige Solutions for AV consultants and venue technical managers specifying ballrooms, function rooms and training suites with operable walls. It covers sensor choice, the combine-state matrix, control sequencing and the tests we use before handover. The same design principles apply whichever control platform is selected for the AV control and signal routing system.

Where the combine state should live

The control processor should be the single owner of the combine state; the DSP, matrix and panels should only follow it. When the DSP runs its own room combiner and the control system separately tracks partitions, a panel press in one room can re-route audio that the DSP believes is still split, and the two disagree until someone reboots something.

A clean ownership model looks like this:

• Inputs: partition sensors (dry contacts) wired to control processor I/O, plus a manual override on the technician panel.
• Owner: the control program, which debounces sensors and publishes one combine state, such as "A+B, C".
• Followers: DSP combine presets, video matrix routes, touch panel layouts, room booking panels and lighting scenes, each driven from that one state.

DSP platforms such as Q-SYS and Biamp Tesira include built-in room combining blocks. Using them is fine, but the control system then sets the DSP's combine state instead of reading partitions independently.

Partition sensor options

Hard-wired contact sensors at the wall's final panel are the most reliable input; operator-selected combine modes are the fallback, not the primary method. The table compares the common choices.

For each wall, specify one sensor at the final (closing) panel, wired as normally-closed so a cut cable reads as "open" and triggers a warning rather than silently combining. Use screened cable back to the rack, and label both ends with the wall reference used on the drawings.

Combine-state matrix

Write the combine-state matrix before any programming starts; it is the single document that the programmer, DSP engineer and venue operator all agree on. A three-way ballroom (A, B, C) with two walls has four valid states.

A state such as "A+C with B closed" is physically impossible when walls are in a line, so the program should reject it and raise a sensor fault instead of trying to route it.

Control sequencing when a wall opens

When a partition opens, the order of actions matters more than speed, because a wrong order produces feedback or a burst of loud programme audio. The sequence we program is:

1. Debounce the sensor for 2–3 seconds so panel movement does not toggle the state.
2. Mute programme and microphone outputs in the affected zones.
3. Recall the DSP combine preset and wait for confirmation from the DSP.
4. Re-route video matrix outputs and set display inputs.
5. Update touch panels: master room shows the combined layout; slave rooms show a lock or mirror page.
6. Recall the combined lighting scene if lighting is integrated.
7. Un-mute at the master room's last-used levels, not at the loudest room's levels.

Splitting uses the reverse order. If an event is running when the wall closes, the program should hold the combined audio state and ask the operator to confirm, because a wall moving mid-event is usually staff testing the track, not a real split.

Audio details that cause most complaints

Most complaints after a combine are about audio, and nearly all trace back to gain structure and echo cancellation settings that were only tuned in the split state. Three rules prevent them:

• Tune gain in every state, not only split. Combining three rooms of ceiling speakers raises acoustic coupling, so microphone gain that was stable in one room may ring in the combined space.
• Use one AEC reference per combined space. When rooms combine for a hybrid meeting, the far-end audio reference must be the combined programme feed, or the remote participants hear echo.
• Use one fixed master room for USB and conferencing endpoints. Only one codec or USB bridge should be active in a combined state; the others mute to avoid duplicate audio paths.

Integration points outside AV

The combine state is useful beyond AV, and publishing it avoids duplicate sensors. Common consumers are the room booking system, which shows the combined room name on door panels; lighting and blinds scenes; HVAC setpoints for the combined zone; and IPTV or digital signage, which can show the combined event name in the foyer. Integration is normally via the control processor's IP interface or a simple contact output, and should be listed in the scope of each trade so the interface is tested, not assumed.

Commissioning pass criteria

Commissioning is complete only when every valid state is proven, both ways, with the walls actually moved. Our pass criteria for a two-wall, three-room space:

• All four valid states reached by moving the walls; each state shown correctly on every panel within 10 seconds.
• Sensor cable disconnected on each wall: system reports a fault and stays in its last safe state.
• No feedback at operating gain with all microphones open in the fully combined state.
• Remote participant hears no echo in each state that supports conferencing.
• Programme audio level in each zone within ±3 dB of the design target after combining.
• Manual override on the technician panel works with sensors disconnected.
• Booking panels and lighting follow the state if integrated.

Record the results in the handover pack together with the state matrix and sensor wiring schedule, so the venue team can re-test after the operable walls are serviced. More venue references are on the Prestige Solutions home page.

FAQ

What happens if a partition sensor fails during an event?

With normally-closed wiring, a failed or cut sensor reads as open and the system flags a fault. The program should hold the current audio state rather than re-routing mid-event, and the operator can set the state manually from the technician panel.

Can room combining be added to an existing function room?

Usually yes, if the DSP supports combine presets and the control processor has spare I/O. The practical work is running sensor cable to each wall track, re-tuning audio in every state and reprogramming panels, which is best done during a scheduled closure.

Why should the control system rather than the DSP own the combine state?

Video routing, touch panels, lighting and booking also depend on the state. When the control processor owns it, every subsystem follows one source, and there is a single place to diagnose when a room behaves unexpectedly.

Recommended next step

Contact Prestige Solutions to review your site drawings and current operating pattern. Call +65 8010 2337, message us on WhatsApp, or email sales@prestigesolutions.com.sg. You can also browse the full product range before the site walk.