Power to the people... "turn that *** racket down of I'm calling the cops"
It's a good question, but could there be a fundamental missing link in this consideration?
Originally Posted by Shantanu
It's vital to appreciate that the speaker draws power from the amplifier. The amplifier does not push power into the speaker - circuit currents don't work that way. And it is you, with your hand responsibly on the amplifier's volume control that provides the throttle control that decides, just as the throttle peddle in your car, how much fuel - electric current - you will allow to flow. The car doesn't start up and roar off unless you depress the throttle, even if there is a 6ltr. lump under the hood. You are the master; not it, and it's exactly the same with amplifiers.
If you sit 3m from the speakers and you like Mahler played loud, you will want more loudness for that 'being there' thrill. You will turn up the volume, and doing that permits more power to flow to the suckling loudspeakers. You might need 100W or more to amplify-up the music that's on your source CD or LP to a decent loudness without over-revving the amp and driving it into clipping where you've red-lined its power potential.
Conversely, if you are confined to a bed sit, have nosy or disagreeable neighbours only too keen to hammer on the wall/ceiling/floor when they consider your music invasive, and you sit close to the speakers and like only choral or banjo music, you will only need one or two watts of power. Having said all that, for all practical purposes, I strongly recommend 40 or 50W of available power and I myself would not choose an amp with much less than that. When wives are out, there is nothing better than a good musical thrashing, and that needs power.
Alan A. Shaw
Harbeth Audio UK