The audio is ran by a 3.5mm from the camera to an xlr cable from the soundboard.
That's the key. You're putting a stereo unbalanced signal into a mono balanced input. Both standards use the same connector, but they're not compatible with each other.
Stereo unbalanced on TRS is:
- Tip = Left
- Ring = Right
- Sleeve = Ground
Mono balanced on TRS is:
- Tip = Hot
- Ring = Cold
- Sleeve = Ground
The balanced input takes the difference, Hot minus Cold, and passes that on as the intended signal. The MASSIVE benefit is that the noise picked up by a long cable run, falls out, and you're left with just the signal...if the signal was actually sent as balanced, which you're not.
When you put a stereo unbalanced signal in there - you can imagine what gets mis-connected to where, just by matching the physical names - it doesn't know the difference, and so it dutifully takes the difference and passes that on.
- If you have a signal that was intended to be stereo, like music for example, then everything that is panned center disappears and you're left with what was off-center. The mix depends on how far off-center each thing is. This is can be used on purpose to remove vocals for karaoke...with varying results in what you end up with for an accompaniment.
- If you essentially have a mono signal presented as centered-stereo, then it disappears entirely.
The solution is to use a different cord that goes into 2 inputs of the sound board: one for left and one for right. If they're separate mono channels, then you have the choice of controlling them together, or using them separately as an audience signal and a cue track or whatever. Or if it's always going to be a single stereo mix, you can make the operator's job a little bit easier by using both inputs of a stereo channel if your board has one available.
