4 ohm taps on an 8 ohm speaker

I've read through most of the tap vs. tap threads and get the gist. But my results from trying 8 and 4 ohm taps would seem to contradict the predictable, at least as I hear it. Maybe just proves "The bottom line: It pays to experiment with the different taps, and no harm will result regardless of which tap is selected."

Just curious if any of you have insight on why I hear better base, maybe a little tighter, and less emphasis on highs using the 8 ohm taps. Here are my speakers' impedance and phase vs. frequency graphs: Minuetto, and my amp's measurements : RM 200. I've read that early SF speakers were developed using tube amps, but not sure if that's true or even applies, especially to the low-end ones.

The sound quality difference is not huge, but still there. True will all music types played at moderate volume in a medium-smallish room (so not pushed to clipping) Also, I haven't tried 1 or 2 ohm taps, but figured why bother if 8 is preferable. Any insight would be appreciated.

Thanks for responding, Al. That's pretty much what I thought but wanted to be sure I understood the science. Also, does it make sense that because the amp's output impedance starts relatively low on the 8 ohm tap and doesn't have a lot of room to go lower on the other taps, the sound quality would vary less from tap to tap relative to higher output impedance amps, for a given speaker? May try the 2 and 1 ohm taps just for grins.

Bifwynne, can you say "off the chart" - literally. Just one of the trade-offs, I'd guess.

Al - Got it. Thanks again.

Bifwynne - Too true.

Later,
Terry