More power for better sound at low volumes?

Rustler 06-19-12:
I'm wondering if a more powerful amp will provide better sound at lower volumes, all other things being equal.

If everything else is indeed equal, including the input sensitivity of the power amps (or the power amp sections of integrated amps), noise levels will be worse with a more powerful amp. If input sensitivities (the input voltages required to drive the amps to full power) are equal, it would mean that the more powerful amp will have higher gain, which will amplify any noise that is introduced or generated at circuit points downstream of the volume control by a greater amount.

I suspect that in those cases where it has been found that a higher powered amp provided better results at lower volumes than a lower powered amp (with the same speakers), the reason was not the difference between the power ratings of the amps in itself, but other differences between the designs of the two amps.

Have you tried listening from different distances, compared to the distance you listen from at normal volumes? Perhaps you can find a listening distance at which differences in room acoustics will partially compensate for the reduced sensitivity to low and high frequencies that our hearing mechanisms have at low volumes (the Fletcher-Munson Effect, that was alluded to by Wolfie and Mapman).

Also, along the lines of Newbee's comment, it would seem to make sense that an amp that operates in Class A, at least when it is putting out low power levels, will generally tend to have lower distortion at those levels than a Class AB design.

Regards,
-- Al

06-21-12: Unsound
Al, Perhaps erroneously, I would have assumed that "all else being equal" extra power would have provided the muscle to reject external noise from seeping in?

Hi Unsound,

No, I don't see it that way. Higher amplifier power will loosely correlate with higher amplifier gain, since amplifiers tend to be designed such they they will be driven to their maximum power capability, whatever that may be, when their input voltage is in the same general area (commonly, although of course not always, in the general area of 1 to 1.5 volts, for unbalanced inputs).

So as I indicated, any noise that is generated or introduced downstream of the volume control will, more often than not, be amplified by a greater amount if the amplifier is higher powered. (Noise originating upstream of the volume control will normally be unaffected by that gain difference, because the volume control setting will be turned up or down to compensate for the gain difference, affecting the signal and noise that originates upstream equally).

Best regards,
-- Al