i have a set of z-5500 and my roomate has a z-5450 that could be sold. we live in an appartment with thin walls, and anytime they're turned up more than 1/4th of the way, we get noise complaints. PM me if you're interested with the max amount that you'll pay. and if you have some lower end speakers that don't need to be as loud, i can also trade, but you need to add in some money of course.