Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Nice...If You Don't Mind Hum and Hiss

I had high hopes for these studio reference monitors, but I was sorely disappointed. Even with no inputs connected, nothing connected but power, if the bass knob was anywhere above zero, there was a constant hum; not loud, but there. I couldn't take it. And if that wasn't enough, the tweeters emitted a constant hiss; again, barely noticeable, but noticeable. And again, this is with no inputs connected, so you can't blame the analog inputs. I thought maybe I got a bad set, so I exchange them for another...Same problems. It is nice that these speakers have the inputs that they do, and the dual volume knobs. They do have a nice sound when there should be sound. Unfortunately, they also have a sound when there should not be any.I do highly recommend American Musical Supply. They were very helpful and I never paid any shipping even after buying these speakers, exchanging them, and then returning them for a full refund.