Runbook: No sound at an event
- Owner
- Dima
- Updated
- 26 August 2026
Purpose
Get music back into the room.
Work down this page in order and do not skip. The answer is almost always in the first four steps, and the whole point of the order is that each step is faster than the one after it.
You are aiming for under sixty seconds of silence. If you reach the rollback section you will still have sound, just with fewer boxes in the chain.
Prerequisites
- The spare RCA to 3.5 mm cable, from the backup pouch
- The 3.5 mm to 3.5 mm cable, for bypassing the controller entirely
- A headphone adapter for the operator's phone, for bypassing the laptop entirely
- Physical access to the back of the controller and to the speaker
If the backup pouch is not present, skip to Rollback, because most of this page ends there anyway.
Procedure
1. The speaker
Speaker powered on? Volume above zero? Correct input selected?
Expected result: the speaker is on, turned up, and set to its line input rather than Bluetooth. If it fails: fix it. This is the single most common cause and it costs five seconds to rule out.
2. The controller has power
Are the controller's lights on?
Expected result: the controller is lit. If it fails: it takes its power from the laptop over USB-C, so it has no battery of its own. Reseat that cable at both ends, then try the spare cable, then the controller's second USB-C port. If the laptop is nearly flat it may have stopped supplying power, so put the laptop on the power station first.
3. The track is actually playing
Is the waveform moving? Channel fader up? Crossfader centred? Master level up?
Expected result: the software is playing and the signal has a path through the mixer. If it fails: a paused deck and a closed fader look identical from two metres away. Check both before touching any cable.
4. The software is pointed at the controller
DJ software -> audio settings -> output device
Expected result: the output device is the controller, not the laptop's own speakers. If it fails: set it to the controller. This is the most common cause for anybody using the rig for the first time, and it survives a reboot badly, so check it after any crash.
5. Split the chain with the headphones
Put the headphones on the controller. Can you hear the track?
Expected result: you can hear it, which means everything up to the controller is healthy and the fault is downstream. If it fails: you cannot hear it, the fault is upstream in the laptop or the controller, and steps 3 and 4 are where it lives. Go back to them.
This is the most valuable step on the page. It splits the problem in half and tells you which half to stop looking at.
6. The output cable and socket
Swap the audio cable for the identical spare.
Expected result: sound returns, and you have learned the old cable is scrap. If it fails: move the cable to the controller's second output and raise that output's own level control, which is separate from the master. It is a free second socket and costs nothing to try.
Verification
- Sound in the room, at a level that suits the space
- The controller's meters are moving and are not sitting in the red
- Both plugs are fully seated, and neither channel has dropped out
- The cable that failed is in a pocket, not back in the pouch, so it cannot be packed and trusted again
Troubleshooting
| Symptom | Likely cause | Fix |
|---|---|---|
| Crackling, cutting in and out | The cable, nearly always | Swap for the spare rather than diagnosing it live |
| One side missing, sound thin and hollow | A plug not fully seated | Push both plugs fully home |
| Hum or buzz | An earth loop through the laptop's power supply | Unplug the laptop from mains or the power station and run it on battery. This fixes it most of the time |
| Harsh and crunchy rather than loud | The controller is being overdriven | Controller down, speaker up |
| Quiet even with the speaker at full | The controller's master is too low | Master to roughly 80 %, then raise the speaker |
| Distorts only on the bass | The speaker is at its physical limit | Turn down. There is nothing else to do |
| Everything sounds fine in headphones, nothing in the room | The fault is downstream of the controller | Step 6, then rollback |
Rollback
There is a way back, and it has four rungs. Each one removes a box from the chain, so work down them only as far as you have to.
| Rung | Chain | Use when |
|---|---|---|
| Full rig | laptop, controller, cable, speaker | normal |
| 1 | laptop, controller, spare cable, speaker | the cable died |
| 2 | laptop, controller second output, cable, speaker | the main socket died |
| 3 | laptop headphone socket, 3.5 mm cable, speaker | the controller died |
| 4 | phone and adapter, speaker | the laptop died |
Rungs 3 and 4 mean no mixing and no cueing. That is a deliberate trade: continuous music from a phone is a better night than a perfect setup with a silent room, and nobody dancing has ever noticed the difference in the first two minutes.
Before dropping a rung, turn the speaker's volume to zero, make the change, then bring it back up. Rewiring into a live speaker is how the speaker gets damaged while you are already having a bad night.
Escalation
| Situation | Who | How |
|---|---|---|
| Every rung has failed and the room is silent | Dima | Move to the venue's own system if it has one, or end the set deliberately rather than letting it trail off |
| The speaker itself is dead | Dima | It is the one item with no fallback in the kit. Borrow, or the event is over |
| Equipment was damaged | Dima | Note it the same night while you still remember, and replace before the next event |
History
| Date | Run by | Notes |
|---|---|---|
| 2026-08-25 | Dima | Intermittent output using an unbalanced adapter cable into the speaker's balanced input. Cause of this document. The fix is the correct balanced cable, and the workaround is the line input |