Higher power=better sound at low volume?

I like Albertporter's theory.

Go to a hi-fi shop and take a resolving pair of bookshelf speakers.
Set them up with three different amplifiers at about 50w, 100w, and 300w.
Assuming they are all quality amplifiers there will be an appreciable difference in sonic characteristics.
Chances are the more powerful amplifier will be more dynamic at low volumes though.
Not necessarily better; just different.
Matching an amplifier with a speaker (and preamp, and source, and ROOM) is time consuming.
Recall buzzword "synergy."

Good luck!

Several factors come into play, both on the amplifier side and the speaker side.

The amplifier's distortion envelope is very important. Large amounts of second harmonic distortion are inaudible, but very small amounts of high order distortion can be quite objectionable. And a type of distortion called "crossover distortion" that occurs at the zero point with class A/B amplifiers is particularly nasty. Its usually masked at medium and high power levels, but is unmasked at low volume levels. If an amplifier's distortion rises at very low power, that's likely a sign of crossover distortion. Class A amps are free from crossover distortion, as are Class D amplifiers, and of course some Class A/B amplifiers are better in this area than others.

As you can infer from the above, loudspeaker efficiency can come into play. If the speakers are high efficiency and the amplifier suffers from crossover distortion, then the amp is more likey to be used at very low power levels where that distortion is most audible. This is probably one of the main reasons high efficiency speaker owners prefer single-ended triode amplifiers, as they are inherently Class A and free from crossover distortion, which under the circumstances would be far more objectionable than the high second order harmonic distortion they do generate.

Also, if a loudspeaker has drivers with significantly differing power compression characteristics (meaning they don't all increaase in loudness at the same rate), then the system has probably been voiced to sound right at medium to high volume levels and will have a tonal imbalance at low volume levels. Usually the tweeter compresses less than the woofer, so most common is a speaker that sounds dull at low volume levels and overly bright at very high volume levels. This is less likely to be an issue with high efficiency loudspeakers, and is a non-issue with single-driver loudspeakers.

Finally, I have read that some woofers have suspension systems that are non-linear at low power levels and so the bass is weak at such levels. Frankly I think it's more likely that weak bass at low power levels is a function of the ear's reduced sensitivity to low frequencies at low volume, but wanted to mention it just in case. Rubber surrounds are most often accused of being non-linear at low power levels.

As long as an amplifier isn't driven into clipping, I don't think it's how powerful the amp is per se that will make the most difference in its low-volume-level performance.

Best of luck to you,

Duke

This subject has been on my mind for a long time. I now have Wilson Sophia,series 2--Had the 1's before.(I think the upgraded 2's are better in the hi mid to upper high range) Now back to a power amp. I should mention I am an apt. dweller so low-volume is a constant way of life for me. I choose the Soph' for its ease of drive (Think; i.pod demo)and less fussy placement,qualities.
I was considering Pass 250.5 or 350.5. I was so confused about sound quality between the 2, I never bought either. I now have a Belles Ref 150 and even they make a 350 ref which I have pondered. I love what I have now but the speakers are still at around 200hrs of use and I figgure I should wait till they have at least 500 or more hrs on them.
So this thread re. someone's 150/250 vs their higher powered version has peaked my interest.
From what I have read, I love everything about the Lamms,'cept the price.BTW, this combo I have now it the best I have ever owned,but---?

Albertporter, FYI, Atma-sphere's smallest amp is their S-30, [30 wpc], although this is a stereo amp, and not a pair of mono-blocks, like the M-60.

The "big boy" is the MA-3, rated at 475 wpc! There are several unique features, including "on the fly" individual tube testing! Here is a link for the MA-3 Amp

I happen to think that Ralph Karsten is a remarkable designer, as well as a remarkable human being! He is one of the last truly independent manufacturers, having a long and proud company history.

Getting back to the question at hand, for SS operating in class A/B, I always went with an amp rated at or above maximum rated speaker power. For SS pure class A, I used an amp rated at 50-75% of speakers rated power. For tube amps, 50% of the speaker's rated power, even less sometimes, if the tube amp was operating pure class A. Just my general rule of thumb, tailored to my own listening preferences.

I think Audiokinesis brought up an important point about playing music at lower volumes: the lower the volume the less bass and treble the human ear/brain perceives in relation to the midrange frequencies. This is compensated for with switches on a lot of mass market equipment ('loudness' switches, etc.) but never seen on the higher end preamps and integrateds.
I definitely agree, though, that each amp/speaker combo has its own sound or personality regardless of wattage.