Power - the reality of hugeness
With respect, you are nullifying your own argument.
Originally Posted by A. E.
For a given, fixed loudspeaker with a given, fixed, certain sensitivity (i.e. loudness out for power in) at a given replay loudness in the listening room (i.e. a known spl) there will be a certain current drawn from the amp. That current will be sucked by the speaker from the amp as the speaker traces the music signal. It will not be pushed by the amp into the speaker: it will only be pulled by the speaker from the amp. If you unplug the speaker there will be zero current flowing out of the amp so it would be immaterial whether the now disconnected amp was rated at 1W or 1000000W: no current would be flowing regardless of how much you turn up the volume control.
If all you need to get a certain speaker playing at a certain loudness with a certain music in a certain room is 10W, if the amp is rated at 450W, then 450-10W= 440W is not being drawn and is power potentially but not actually usable by those speakers. It would seem rather daft to pay for such a huge unusable power reserve with the elevated risk that component failure or misuse could destroy your speakers in a flash.
As for sonic perception of 'quality' yes, of course this is directly related to loudness. But that applies equally to turning the volume up and down on an amp rated at 10W or 450W. And as there is absolutely no standardisation as to what actual listening loudness (say) 11 o'clock volume on amp A produces compared to 11 o'clock setting on amplifier B (i.e the gain of the amp from the input to output terminals), those who have constructed careful A-B amp tests where the loudness is measured with a microphone at the listening seat and not guessed, usually report that the subjective differences between amplifiers regardless of power rating almost or actually vanish.
If you are going to test drive an Aston Martin and a Ford run-around, logically you should test them at exactly the same road speed. Testing amplifiers (or speakers for that matter) without knowing how loud they are is like covering-up the speedometer and then test driving two cars: a useless comparison likely to result in erroneous and expensive conclusions.
Alan A. Shaw
Harbeth Audio UK