Does the power of an amplifier really matter?


Excuse my ignorance, but I am trying to understand the meaning of amplifier power. A doubling of amplifier output power results in a 3dB increase in sound-pressure level. So, if I listen to my stereo at a volume of say, 70 dB, what is the difference in a 100W amp vs. 250 W amp? If I listen at 70 dB, is more power delivered to the speakers with a 250W amp vs. 100W amp (resulting in better driver control)? I am not sure that is the case. Is it that a higher powered amp delivers a given amount of power more cleanly? Not sure if that is true as well. Can anyone educate me on this fundamental property of amplifiers?
number1cuban

Showing 2 responses by jeffreybehr

To Pabelson--WOW, a highly intelligent and thoughtful response. I was thinking along the same lines but you said it first and VERY well.

To Elevick--if your '...around 89db' is intended to address a sort-of-average speaker's sensitivity, don't forget that those sensitivity measurements are done at 1 meter. At 2 meters, that SPL is down 6dB (I BELIEVE; someone pls correct me if that's wrong)...which, of course, reinforces your point about power requirements.

Overall, IMO the 2 most-important determinants of power requirements are speaker sensitivity and desired listening levels. There is maybe 10 deciBels difference in typical sensitivities in popular speakers*, and there's probably more like 20dB difference in typical average listening levels. Combined, that's a 30dB difference which is HUGE.

Eldartford is correct IMO--'sufficient' power gives you a sense of ease, of effortlessness, in playing dynamic music.

* I'm NOT including the rare examples of those speakers in the high 90s and 100s. If I did, that difference might be 20 or more deciBels!
.
Number1, yours is a dilemma common to many of us.

There are no easy answers in spite of what the measurists would have you believe. The ability to maintain voltage in the face of low impedances...IOW the ability to deliver high current...probably is one factor, and the amp's sound at and beyond clipping probably is another.

Amplifier power is just a beginning, and probably not a very good one.
.