Re: Selecting proper Ohm load to speakers
I don't think the amp cares too much when it's expecting say a 4ohm load, and instead encounters an 8ohm. Ie, the Output trannie is getting more impedance, which is okay, by one degree. The other way round, when it's expecting 8 and finds 4, it's getting dangerous.
Alot of guys will says it's fine either way, for one degree of mismatch (ie 4 to 8), but you're asking for trouble when amp expects 16 and instead get 4.
As far has using a choice of output 'taps', power, impedance, and wiring schemes are all factors. I know if you use the 4 ohm tap into you cab, you'll get a diferent volume level than if you took the same cab and powered it via the 8 out...