Worked fine in my studio. Major unsolvable (at the time) base to mid feedback at first live gig where there were few soft furnishings, solid flaws etc, and I would have blown my zxr 12s had I continued. Spoke to Harrison at Gear4Music who suggested turning base EQ right down, roll down mid EQ and roll off gain even more than I had already done. Result is a sennheiser e945 works as if it were wired. Brilliant. Just a bit disappointing that there's no trouble shooting top tips for feedback in the "manual" hence 4 stars not 5, or if there are I couldn't find them. But now I know I ll be buying more. Yes they are more expensive than some other brands but I've had the Xvive guitar U2 for 18 months, have gigged the hell out of it and it seems bombproof, which when you are gigging every week is what you need.