maximum watts (1 Viewer)

[EmaxJS]

I currently have a very old Pioneer tuner in my bedroom that is 125w X 2 still hooked to the original huge floor standing speakers. I never listen to it at louder than a quarter of it's volume. I'm thinking about replacing my Bose Acoustimass 6 speaker set-up in my home theater and I was wondering since they are only rated at a max of 100 watts each if I would blow them by using them with the tuner in my bedroom?

I thought I had read that it was actually good to get an amp that was rated more watts than the speakers since under powering is often the culprit with burning out speakers. and unless you keep the amp at full volume you are nefver sending out the full wattage anyway.

Thanks!

 

[Mark Tranchant]

I thought I had read that it was actually good to get an amp that was rated more watts than the speakers since under powering is often the culprit with burning out speakers. and unless you keep the amp at full volume you are never sending out the full wattage anyway.

Correct. It is clipping distortion from an underpowered amp that caused most speaker failure.
It doesn't matter how huge an amp you connect them to: if you are going to listen to them at similar volume to when they were in your HT, then they'll be getting the same power from the amp.
You also can't judge the output of the power amp by the position of the volume control. The power amps work as a fixed multiplier (which I'll call m): if you put x volts in, you'll get mx volts out, which will give (mx)^2/r watts into an r ohm speaker. The volume control is effectively a variable multiplier (lets call it n) before the power amp that controls the level of the input (which I'll call y). So x, the output from the volume control section, is ny, and the power output is (mny)^2/r.
Whew! What I'm trying to show is that the power output is dependent on both the volume control position n and the input voltage y. This gave some problems in the early days of CD, when CD players gave much higher voltage output than other components, and old amps with a CD plugged into a line input were giving full power output long before the volume control went to full.
Also, a doubling of perceived volume requires a fourfold increase in power, so "quarter volume" would relate to one-sixteenth of the power output of the amp.