Speaker hook up question.

Could be. I have usually found the 8ohm taps to be best for most of my speakers, even some 4 ohm ones where the amount of power needed to drive the bass wasn't an issue. My 6 ohm speakers, which have a min impedence of 5 ohms sound much better on 8 ohms. Depends on your speakers and you ears. Try them both - you won't damage anything.

Hmmm, I was always told to go lower to avoid damaging the amp? I never use the taps whose impedance is higher than my speakers.