XLR (4-pin, headset) pinout
XLR 4-Pin Intercom Headset Pinout
Wired party-line intercom headsets use a 4-pin XLR with the microphone on pins 1 and 2 (ground and hot) and the earphone on pins 3 and 4 (ground and hot) in the Clear-Com convention that most of the industry follows. Some headset brands wire differently, which is why a working headset can go silent on the next brand of beltpack.
| Pin | Signal | Notes |
|---|---|---|
| 1 | Mic ground | Microphone return and shield. |
| 2 | Mic hot (+) | Microphone signal into the beltpack. |
| 3 | Earphone ground | Headphone return. |
| 4 | Earphone hot (+) | Headphone drive from the beltpack. |
What it’s used for
The 4-pin XLR is the standard headset connector on wired party-line comms: the beltpack provides mic preamp and headphone drive, and the headset is just a mic and a speaker on four pins. Single-muff and dual-muff headsets wire identically.
The connector also appears on cameras and speaker-station panels; the headset convention above is what matters on a show floor. Party-line line-level and power ride the separate 3-pin XLR comms line between beltpacks, not this connector.
Wiring & termination notes
- The table above is the Clear-Com convention, which most third-party headsets follow. Some manufacturers (notably certain Beyerdynamic and older Telex/RTS models) assign pins differently; adapters and re-terminations between brands are routine comms-shop work.
- A headset with a dead mic but working ears (or the reverse) across brands is almost always a pinout mismatch, not a fault.
- Dynamic mic elements are standard; electret headsets need a beltpack that supplies bias and do not cross over reliably.
- Keep headset cables out of feeder bundles; party-line comms is unbalanced enough to collect hum from proximity.
Frequently asked questions
Are all 4-pin XLR intercom headsets wired the same?
No. The Clear-Com convention (mic on 1/2, phones on 3/4) dominates, but several headset brands historically wired their own way. Check the pinout before blaming the beltpack.
Can I use a 5-pin XLR headset on a 4-pin beltpack?
The 5-pin headset version is the dual-earphone (stereo/split-channel) variant; adapters exist that sum or select. The connectors do not intermate, so it is a cable decision, not a force-it decision.