is it unreasonable to expect absolutely no noise using a wireless? When i turn it on there is a very faint hiss. Like a tiny airleak from a tire. Not a showstopper, but not the absolute silence of a cable either. I notice it more in the pa, probably because of the horns. I purchased this unit used, so i dont know what normal is. I didnt notice the noise testing in the store, but then again i wasnt turned up very loud. I had quit using it a while ago due to a static-like sound but recently discovered this was a cable issue. So in my test with the new cable the bad noise was gone, but there is still the slight sound of "air".