4 ohm taps on an 8 ohm speaker

Bruce (Bifwynne), looks like you and I and Anthony (Clio09) were all responding at the same time. Great minds think alike! The one very slight qualification I would make to your post is that the reference to higher frequencies being less augmented relative to the bass when the speaker is driven by an amp having lower output impedance depends, of course, on how the impedance of the particular speaker varies as a function of frequency. Although the impedance behavior implicit in your statement is a common one.

Best,
-- Al

Right on Al. Actually, what I had in mind was a speaker with low'ish impedance in the bass/lower midrange frequencies, with a peak at the mid/tweeter crossover point. As I'm sure most would agree, matching a high'ish output impedance tube amp to that kind of load would tend to attenuate bass and augment the mids and low treble.

I would add one more point. Current delivery capability, albeit a subset of my comment about an amp operating within its design parameters.

More specifically, many speakers not only have low'ish impedances in the bass frequency region, but also capacitive (negative) phase angles. In other words, tough loads. Hopefully, regardless of the tap used, the amp in question will have enough power supply reserve to muscle its way through the tough spots.

Best,

BIF

Thanks a lot for the explanation Al, you ARE the man!!!
I think you nailed it with the first line in your last paragraph: "The bottom line: It pays to experiment with the different taps, and no harm will result regardless of which tap is selected."

Cheers,
John

Thanks for the responses gentlemen. Interesting stuff. Glad to hear I'm not hurting the amp. It does sound much better on the 4 ohm taps.

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.