Hey guys. I'm going to try and describe our current IEM setup and hopefully it will make sense. I need some help diagnosing a couple issues we've been having when we're playing live. Three piece cover band. We all use IEMs (Shure headphones). No stage (wedge) monitors at all. PA is a basic newer Peavey unit. I'm not sure on the exact model the guitarist has, but it's similar to this: http://www.musiciansfriend.com/pro-audio/peavey-pvi8500-8-channel-400w-powered-pa-head-w-bluetooth-and-fx We run two speakers on a pole off of it. No other subs, etc. For the IEMs, we run a mono cable from the monitor out on the front of the PA head. On the other end of the mono cable, I have a mono to stereo adapter, going into a basic Behringer headphone amp (http://www.musiciansfriend.com/pro-audio/behringer-microamp-ha400-headphone-amp). The headphone amp has four outs on it (we use three, one for each person in the band). Guitarist and I both use wireless units for our headphones (Galaxy Audio AS-900 on different channels). The drummer just has a headphone extension cable going from the Behringer headphone amp to his own headphones. We are using stereo headphone cables from the headphone outs on the Behringer (guitarist and I are using Y splitter cables to go into our wireless units). None of this seems to make a difference, as we're all experiencing the same issues. The biggest issue we've been having is that every other show, we seem to get really crummy sound in our headphones, even though we're hooking things up the same way from show to show. For instance, when we were playing Saturday night, we were all getting sound in only one ear (maybe a tiny amount in the other), which was fairly distorted. Fortunately, everyone said what was coming through the mains sounded great. I had to crank the monitor out level on the PA up to about 3 o'clock for us to get audible sound in our headphones. I'm sure I'm hooking something up incorrectly, but I can't figure out what. All of this equipment is pretty new, so I'd be fairly shocked if something was faulty or going bad already. Any help or advice would be appreciated.