Audio Input Not Detected
2 min readTroubleshooting
Fix audio input issues in CueSync — microphone access, LTC timecode input, and the Booth Input level.
Where CueSync Uses an Audio Input
CueSync reads an audio input for two things:
- LTC timecode (Theatre and Production) — decodes SMPTE timecode from a dedicated input so cues can follow an external timecode source. Switch it on under Settings → Timecode → Source Configuration → LTC (Linear Timecode).
- Booth Input (experimental) — measures the energy of the room (overall level plus a bass, mid and high split) to drive the pixel wall and the CueSync Bus. Switch it on under Settings → Audio → Booth Input.
The beat itself comes from a Pioneer deck over PRO DJ LINK, a file in Local Audio, Ableton Link, OS2L or a tap — see Pioneer PRO DJ LINK Not Detected for how to keep the beat when a link drops.
Check macOS Microphone Permission
macOS treats every audio input as a "microphone". If the permission was denied when you armed LTC or Booth Input:
- Open System Settings → Privacy & Security → Microphone.
- Ensure CueSync is in the list and the toggle is on.
- Restart CueSync after granting permission.
Selecting the Correct Input Device
For LTC:
- Open CueSync → Settings → Timecode and turn on LTC (Linear Timecode).
- In the LTC Audio Input card, pick your interface's input and click Start Capture (Refresh re-scans the devices).
- Open the Timecode screen and confirm the LTC source row shows a signal and locks while the sender is running.
For Booth Input:
- Open Settings → Audio → Booth Input and switch on Capture the booth.
- Choose a device — it defaults to the system default input.
- Confirm the status line reports levels. A device that cannot be opened reports "not capturing" rather than silence.
If your interface is not in the list:
- Confirm it is connected and recognized by macOS (check System Settings → Sound → Input)
- Try unplugging and replugging the USB/Thunderbolt connection
- For aggregate devices, build the aggregate in Audio MIDI Setup (Applications → Utilities)
Common Fixes
| Symptom | Fix |
|---|---|
| No devices in the list | Grant microphone permission; restart CueSync |
| Interface listed but no signal | Check cable and input gain on the hardware; confirm the correct input channel |
| LTC never locks | Check the sender's LTC output level and the interface gain, and confirm the selected device is the one the LTC is patched to |
| Works then stops randomly | Disable macOS "automatic sample rate switching" for the device in Audio MIDI Setup |
Still No Audio?
Restart the CoreAudio daemon without rebooting your Mac:
sudo killall coreaudiod
Then reopen CueSync. This resolves most persistent audio device issues on macOS.
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