How much power is to much power?


When is an amp overkill for a speaker? More specifically, I have 91db speakers and I'm considering two SS amps, one 140 watts and the other 200 watts. Are they both too much? Is it too much simply because you're paying for extra power but don't need it, or because it's a detriment to the overall system sound?

Thanks.
128x128jtnicolosi
Vett93, You have learned something of great value, I think. Now to have an even more complete understanding of amp/speaker matching, consider that not only do speakers have an irregular impedence so do amplifiers have an output impedence that is irregular. Not so much SS which usually have a very low output impedence and its not a real issue, but tube amps can, and do, have output impedences that are fairly high and can make a substantial difference in what you hear from speakers. It's has been discussed here before so some night when you can't sleep, it will give you something to research. :-)
09-13-08: Vett93 said:
"What does "more control of bass" mean? If you meant sufficient current to drive the bass woofers without more distortion, then it is equivalent to a higher SPL. If you meant a higher damping factor, then it is independent to the wattage anyway."

I'm talking about effective damping, not damping factor. DF is part of the equation, but a 100 wpc with a damping factor of 1000 isn't going to control the woofers as well as my 1000 wpc amp with a DF of 1000. Someone up the thread said something along the lines that watts are like horse power. There's something too that.

Uncontrolled bass is too bloomy and resonant. An amp that grabs the woofers and prevents them from uncontrolled ringing is what's needed.

Dave
It depends.

On room size, how loud you listen. That's about it.

Realize that power alone is not always the answer. The amp has to be able to deliver power smoothly into the speakers variable impedance at different frequencies. Amps that double in power from 8 to 4 to 2 ohms do this best. Some speakers are more difficult to drive due to complex impedance loads at various frequencies. Others are less demaning.
What does "effective damping" mean then? :-)

I think what you are referring to is not damping. Rather, it is the sheer power.

I have 4 amps in the house, from 8Wpc 300B SET to 200/400Wpc into 8/4ohm load all SS power amp. The damping factor ranges from 5 to 700. I would not say a higher damping factor will yield the best bass for all kinds of music.

I've found that for Jazz and string music, a mid level DF will yield the best bass to my ears. A high DF means a dryer bass, again to my ears.
You probably like a little bloom in your bass, which is not uncommon. I listen to lots of music with tons of bass and I play in orchestras and bands with "real bass" so I don't like any added bloom.

DF is a technical term that doesn't adequately explain the ability of an amp to control the woofers. If your SET amp had a damping factor of 1000 it still couldn't control many woofers.

Dave