I just returned some z-680's. Even though I had the newer control pod with the latest firmware, there is still a noticeable hiss coming from the center channel. The subwoofer also sucks. If you turn the sub volume all the way down it turns it off. When you turn it one notch up, it gets way too loud. It's not good for music at all, just sounds like a boomy mess. I'm going to get the megaworks 550 since they are much more musical, and you can actually turn the subwoofer down without turning it off.