using a DJM 800. I will be playing through two channels, not clipping just clean signals. Out of nowhere randomly my left output will have a small pop then instantly decrease in volume compared to the right. The signal master output LEDs still show a balanced signal going out. I narrowed the problem to be coming down to the left XLR output. Its not cables or anything like that. The sound will return to normal volume randomly varying in time. Sometimes it will come back in a minute other times half an hour. I dont want to send this out for repairs before I have an idea what the problem is first.
How old is your mixer?.It is a common problem with live sound mixers when with the time and a combination of moist the inputs or outputs become oxidized and even you can not see it at bare eye. You would need either to clean deeply or change your Xlr outputs or the RCA inputs, because you got like a virtual impedance gain by the rust.
If original poster is determind it’s not cable (which it sounds like it is), is the mixer backed up against a wall or something wedging the cable in at a slightly awkward angle?
nope its not being wedged against anything. the strange thing is the audio drop will happen randomly without correlation to anything. Then the audio will come back randomly again.
Open up the XLR jack and rewire it. Or, if you don’t now how to, buy new good quality XLRs. I’d pretty much guarantee your problem will sdisappear then.
I always buy ones with Neutrik connectors and Van Damme cabling. Can’t go wrong with this combo in my experience.
That, to me Screams bad cable. Do what was suggested and or buy new ones. As for the audio dropping out with no discernable pattern, that’s indicative of a shorted cable.