I've noticed something funny when running my Focus at 2 ohms with 2 Wizzy 10's. The sound is very different, much more bassy and tending toward boominess in live acoustic spaces. It also sounds much "hotter" than running a single speaker at 4 ohms. I'm trying to figure out how much of what I'm hearing is some physical principle at play, and how much is psychoacoustics. Some random observations: - The 2 ohm thing actually sounds wonderful for slab on those rare occasions when I play it. It kind of fattens up the sound and gives it a very charged presence that i like a lot. For DB, it's not so much that it's a bad sound as it is that it's a fundamentally *different* sound; Edgy, agressive, and more sonically opaque, if that makes any sense. - I can't tell how much of the extra bass response is due to coupling with the floor. I'd try stacking the cabs on a chair, but they're tall enough that it would seem unstable somehow. - Last, of course, is the fact that when you need to take 2 cabinets, you're probably just gonna be too damn loud for transparent sound (although the same rig sounds pretty good in deader rooms). So, is there really any sonic difference between 4 and 2 ohms, or am I just imagining things? What's the science behind the sound?