Popping and snapping sound followed by sound card dropout

Only a problem at certain venues, but sometimes I will get some loud popping and snapping noises followed by the soundcard resetting. This happens at the worst times. When the bride is walking down the isle. During the first dance. Changing outlets usually fixes it, but if I stay on the outlet it will happen again. I'm building a map in my brain of outlets to avoid at venues but there has got to be a better way. I can simulate the problem (other than the snapping and popping) by momentarily cutting power and restoring it. The sound card times out. It's only been a problem since I upgraded my sound. I added up my speakers and they can pull 22 amps at peak. I think when I'm plugged into bad power I'm getting voltage drops and it's cutting power to my Vci 400 momentarily. I am getting a battery backup UPS to plug my vestax into to keep this from happening again. It was a once a year occurance but now it's about once every two months, testing my system at high volume has helped stop it but I think the battery backup is a better solution

I always get the same bull crap from the venue. (We've had live bands in here and they don't have a problem) or (xyz iTunes DJ never has any problems with the power)

Hey, update: got an uninterruptible power supply. Was at one of the venues I've been having trouble with, with a bunch of Christmas lights everywhere. Had 3 sound card dropouts with the UPS running my vestax. I moved to a different outlet and No problems the rest of the night.

I am stumped. If my UPS is giving me perfect uninterrupted power why would changing outlets help?

It could be the wiring of the outlet as some outlets may have more conduit running near them which can cause interference. A similar thing happened to me at a house party I played a few years back. It turned out that the breaker was on the other side of the wall and it was causing severe line noise.