I was really excited to replace my Harman Kardon sub/sats that came with the Dell.... the truth is the HK's were actually really pretty darn good. But I thought I'd make the leap to something better. The Z3's came, I unpacked them, and hooked them up. The first thing you notice is that the satellites are very heavy.... ah, a good sign....??? I placed the satellites on the desk and the subwoofer on the floor under my desk. Fired up the system. Ugh. Terrible. Granted, the subwoofer has an independent volume control, but no matter where you set that, the separation from sub to sats is horrible. The sats are too treble'y, the sub is too boomy (in a bad resonant way) and so all you hear is screachy treble and this really weird crappy boomy sound from under the desk. Keep reading, it gets better... I wasn't willing to throw in the towel, so I went to Home Depot, bought some wood, and built a box, 14" high, 10" square all sides. I filled the box with sand to kill the resonance, and put the sub on the box. Now the sub sits on this box under my desk, with the sats sitting on the desk right over it.
Simply bringing that sub up to nearly the same level as the sats made a HUGE difference; I mean the critical difference. I'm sure that sitting what is basically a low-quality sub on 40 lbs of sand has helped it 1000% as well. It has made the sub very clean with none of that goofy resonant boominess left. So for the $60 + $25 other materials, I have a speaker system that was everything I hoped for!