So i've had my new iMac for about 4 months now, and i've been having a super annoying problem with Garageband ever since. I am a guitar player and when I try to play guitar through Garageband, I get a loud feedback ringing. I can still hear my playing, but when i stop for a second the feedback gets loud again. I use Metal and Scorching Solo, and when I set it to On with feeback protection, it forces me to set it to just On. Pretty weird, anyone know how to make this stop? And I do have the input set to built in input. Please help