First off, thanks for all of the help so far. I really liked the AVATAR site for speaker cabs. What I need to know is, Should I get a 4, 8, or 16 ohm cab for my Twinmaster Plus head? It will handle them all. But,I have heard that some amps work better at certain impedence. If there are any BUDDA owners out there with experience, I would appreciate your input. I am thinking about getting some Eminence Texas Heat speakers loaded into an Avater 2X12.
8 ohms is pretty common for 1x12 and 2x12 combos and cabs. 16 ohms is the norm for 4x12 cabs. If you are going to use the cab with another cab or combo you will want to get a cab with the same impedance.
As far as mixing impedances they will make a slight difference in the sound. For example, if you plug an 8 ohm speaker into an amp that is set at 4 ohms the tubes will work a little harder. The amp will distort sooner and there should be a drop in volume. The amp might sound a little warmer as well. The same would apply to a 16 ohm cab plugged into an amp set at 8 ohms. If the impedances are matched (8 ohm cab into 8 ohm amp) the amp will function normally. A very important rule, you must never plug a cab with lower impedance into an amp with higher impedance. Example: 4 ohm cab into an amp set at 8 ohms. This will damage the amp.