So I recently started using an HD500 live for the purpose of making life easier when i play fill in gigs here around town. It's much easier to load in with a guitar and board as opposed to my normal church rig that consist of a combo amp, 14spc rack and pedal board. I guess the down side was that our sound tech at church loved it so much she decided that she didn't want my normal rig on stage anymore. I was gracious and honored her wishes and began the process of trying to duplicate what my normal rig sounds like. It is about 97% there... ...here's my dilemma. The HD500 sounds great through FOH but absolutely terrible, fizzy overdriven transistor radio like through the aviom system. I am using Shure SE415 IEM that sound awesome. In regards to the monitor mix, the guitar by itself sounds fine, almost exactly what the house sounds like, the rest of the band, Keys, Bass, Acoustic guitar and lead vocal all sound great as well as individually. Bring them all together and the guitar is the big loser in the group sounding distorted, fizzy and absolutely terrible to the point where after the first song i pretty much tear the IEM out of my head while the rest of the instruments sound normal. I have adjusted everything i could at my end and the FOH has been doing what they can but no change. Is there anything on the HD500 that needs to be addressed or is it up to FOH. We have looked at the gain levels on the sub mix going to the Aviom and nothing out of the ordinary. Confused and FRUSTRATED!