I've recently begun to put together a new bass rig. Just today I won a Trace Elliot AH300 on eBay (300W @ 4ohms), and now I'm looking for a cab to go with it. I'm almost certainly going to order an Avatar B410NEO, but I don't know what impedance to get it in. I am a college student with very limited resources for storing or transporting such bulky pieces of equipment, so this will probably be my only cab in the foreseeable future. However, I'm still wondering whether to get the cab in 8ohms, so that maybe one day I can decide to add another cab. The Avatar website says that using an 8ohm cabinet instead of a 4ohm cabinet will cost me only 3db in volume. However, this doesn't make sense to me from a basic P=V^2/R perspective; wouldn't twice the impedance, at the same voltage, lead to half the power? The band I play in is very loud; I'm currently borrowing a friend's Ashdown MAG300 (300W) into 4ohms, and both input and output levels are always about halfway up. I'm afraid that if I use an 8ohm cab with the Trace Elliot, I will have to keep it cranked at all times, which I'm not too comfortable with. Can anyone help me out?