Intercom System Planning and Channel Plans
By VJ Ries · Published 2026-07-12 · Updated 2026-08-01 · 10 min read
Intercom system planning means deciding how the crew talks during a show and writing it down so anyone can wire and operate it. Topology comes first: partyline (a shared bus where everyone on a channel hears everyone) or matrix (point-to-point routing that gives each panel its own custom mix). Then build a channel plan: a table of who talks to whom and on what. Add IFB feeds for on-air talent. File it in the tech pack beside the signal flow. Done in preproduction, comms stops being the thing that fails right before doors.
What does intercom system planning actually cover?
Program audio is one system. Production comms is another. It is the private talk network that a TD calls a show on. A stage manager moves scenery on it; a camera op takes direction. None of it reaches the room. Six things get decided on paper before anything gets patched: the topology, the channels, the panels and beltpacks, the IFB feeds, whether any of it is wireless, and how all of that is documented.
Out of that comes a small stack of documents. A channel plan and a panel or key layout. The comms runs on the same signal-flow diagram as the rest of the show. Skip it and comms works fine in rehearsal, then falls apart the moment the crew doubles and nobody agreed where scene changes get called.
Partyline vs matrix intercom: which do you need?
Everything downstream follows from this first decision. Partyline is a shared bus: every station keyed to a channel hears every other station on it, like a conference call that is always live; matrix puts a central frame in the middle that routes any port to any port, so each panel gets a custom set of talk and listen keys for that position. Partyline is simple and cheap. It also runs out of room fast. Matrix is flexible and scalable. It costs more in money. It costs more in programming and setup time too.
| Factor | Partyline | Matrix |
|---|---|---|
| Topology | Shared bus, everyone on a channel hears everyone | Central frame routes any port to any port |
| Best for | Small crews, few conversations, fast get-in | Large shows, many roles, a custom mix per position |
| Channels | A handful of shared channels (commonly 2 to 4 on a beltpack, confirm the model) | Effectively per-panel custom key layouts |
| Cost and setup | Lower, little to configure | Higher, needs a frame and programming time |
| Typical failure mode | One loud talker is on everyone's channel at once | A misprogrammed key sends the wrong feed to the wrong panel |
| Scales by | Adding channels and interface packs | Adding ports and panels to the frame |
Partyline serves most small venues. Houses of worship too, and single-room corporate gigs. A few channels, a rack of beltpacks. Done. You move to matrix when many groups must not hear each other, or when you need per-position mixes. Same when you are tying rooms or trucks or remote sites together. Many rigs are hybrid: a matrix frame with partyline channels hung off interface cards, the cheapest way to give a big crew a lot of beltpacks.
What goes in an intercom channel plan?
For comms, the channel plan is the master document: the intercom equivalent of a signal-flow diagram. It answers one question. Who talks to whom, and on what. There is no public standard form. Build your own, and a plain table beats a clever one.
| Channel | Label | Who is on it | Purpose | Notes |
|---|---|---|---|---|
| 1 | PROD | TD, A1, LD, video, stage manager | Main show-calling channel | Everyone monitors, TD drives |
| 2 | STAGE | Stage manager, deck crew, stagehands | Scene changes and deck cues | Kept off PROD to cut clutter |
| 3 | VIDEO | Director, camera ops, playback | Camera and playback coordination | Cam ops answer here, not on PROD |
| 4 | AUDIO | A1, A2, RF tech | Audio crew coordination | Private to audio |
| IFB1 | HOST IFB | Producer to host earpiece | One-way program plus interrupt | A feed, not a conversation |
Notice the shape. Conversations that belong together share a channel; ones that would step on each other get split. PROD is the spine everyone monitors. Three working channels sit under it. STAGE. VIDEO. AUDIO. Each sub-crew lives on one, so the TD is not buried under deck chatter.
How do you build a channel plan, step by step?
Build it from the crew outward, because working inward from the hardware is the mistake: the gear count falls out of the plan, and if you start from the beltpacks you happen to own you will bend the show to the gear instead.
- List every person on headset and what they do, by role, not by name. Roles outlast the freelancer, so next month's plan reuses the rows.
- Group roles by conversation: who genuinely needs to hear each other in real time. Each group becomes a channel.
- Name each channel in plain language (PROD, STAGE, VIDEO, AUDIO), the same short name the operator sees on the panel.
- Assign panels and beltpacks to channels. On a matrix, lay out each panel's keys so the most-used talk key is easiest to reach.
- Mark IFB and any one-way feeds separately. They are destinations, not conversations.
- Walk the plan with the people who will use it. The stage manager and TD will spot a missing channel in ten seconds.
Where does IFB fit in the comms plan?
IFB stands for interruptible foldback. It is a one-way feed of program audio to on-air talent that a producer can duck and talk over. The host hears the show in an earpiece. When the producer keys down, program dims and the talent hears the cue ("wrap in thirty"). It is not a partyline channel, so do not plan it as one.
On the plan, treat every IFB feed as its own destination. Give it a named source (usually a program or mix-minus bus) and an interrupt source (the producer's key). Draw it as a single arrow into the talent earpiece, like any other one-way return on a worked multicamera livestream example. Two hosts who need independent cues are two IFB feeds. One will not do it: a shared bus cannot address one host without the other.
How many panels, beltpacks, and ports do you need?
Once the channel plan exists, sizing is arithmetic. Count the fixed positions that get a permanent panel. Count the roaming crew that get a beltpack. Count the one-way IFB destinations. Then reconcile all of it against what the frame and interfaces actually provide. A port shortfall should show up in the office. The truck is a terrible place to find one.
Fixed positions needing a panel: TD, A1, A2, LD, video, stage manager = 6 Roaming crew needing a beltpack: 2 stagehands, 1 spot op, 1 camera utility = 4 One-way IFB destinations: 2 host earpieces = 2 Matrix ports for fixed panels and IFB feeds: 6 + 2 = 8 Partyline beltpacks share a channel, so the 4 beltpacks ride one interface pack, not 4 separate ports Wireless comms: 4 beltpacks size against packs per antenna and antenna coverage, not one frequency per pack (per-antenna limits vary by system and region, confirm the datasheet)
These are planning placeholders. Real key counts, partyline stations per interface, and frame port capacity vary by model, so size against the datasheets before you buy or rent.
Where does comms live in the tech pack?
Comms belongs in the same tech pack as the rest of the show. Not in a separate file that lives only in the comms tech's head. Three things travel together. The channel plan, which is the table above. The physical runs on the signal-flow diagram. The comms cables in the cable schedule, with endpoints and IDs. Every comms run, wired or wireless, is just a cable, so it schedules like the rest.
Put comms on the preproduction checklist so it is planned in the same pass as power and video. Label the runs so the crew can trace them (see labeling cables and ports). Ship it as one packet and everyone reads the same channel names. WireFlow keeps the comms runs on the same project as the signal flow and derives the cable schedule and gear list from it, so plan and wiring cannot quietly drift apart.
Frequently asked questions
- Partyline or matrix for a small church or venue?
- For a handful of headsets and one or two conversations, partyline is almost always right. Fewer boxes. Nothing to program. Learnable in a cue. Move toward matrix when several groups must not hear each other. Same when you need a custom mix per position, or when you are linking rooms or trucks or remote sites. Hybrid rigs (a matrix frame with partyline channels hung off it) give a big crew cheap beltpacks.
- Is intercom the same as IFB?
- No. Intercom (partyline or matrix) is the crew's two-way talk network. IFB is a one-way feed of program audio to talent that a producer can interrupt. They share cable but differ on the plan: intercom rows are conversations, IFB rows are destinations. Keeping them separate is what stops a cue from landing in the wrong ear.
- Can I run comms over my AV network?
- Many modern intercom systems ride IP and can share AES67 or Dante style infrastructure. Whether yours does is specific to the product. So is how it wants VLANs handled, and bandwidth, and clocking. Check the manufacturer's networking requirements and design to match rather than assuming comms can share any switch. When in doubt, give comms its own documented path.
- Do I need a channel-plan template to start?
- There is no standardized public channel-plan form, so do not hunt for the one true template. A five-column table (channel, label, who is on it, purpose, notes) covers almost every show. The discipline that matters is filling it in honestly and keeping the labels identical to the physical panels.
- Wired or wireless comms?
- Wired is cheaper. No RF to coordinate. It never runs out of battery, so fixed positions almost always go wired. Wireless earns its cost for roaming crew (deck, spot, camera utility) who cannot drag a cable. Modern digital packs (DECT based systems) allocate RF dynamically rather than needing one frequency each, so the real limits are packs per antenna and antenna coverage; analog UHF packs share the base station's frequency pair. Either way, plan antenna placement and cabling early, and confirm the per-antenna pack count on the datasheet.
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