Heat/Efficency of Speakers


What % of power sent to the speakers is turned to waste heat? That's the short version of my question.

I'm looking to minimize waste heat accross my stereo as my listening room is unforgiving come summer; no cooling and a computer system which cannot be relocated. I understand amplifier efficency & the classes as well as speaker efficency measured as W/db however the interplay eludes me.

Taking two hypothetical amplifiers: a Class A amplifier outputting 10W w/ 100W from the wall & a Class D outputting 200 w/ 220W draw I understand the D will be the cooler operator however this is where the discussion tends to end, D only wasting 20W vs the A amplifier's 90W. Considering appropriate speaker matches to each amp(as well as a standard HE speaker at say 95db/w), how do I determine the wattage converted sound and the watts spent as heat?

I'm asking because I was previously running a 10W tube amplifier in this room(4xel84 tubes) with 96db speakers. This was bearable in two hour doses this last summer. My friend assures me any Class D amplifier and many AB amps would have no such heating problems and says it's class not wattage that is my issue. Before I move to a different amplifier technology(and swap speakers, these voiced for SE tube partnering) I want to understand this issue fully. I'm unconcerned with power usage and only care about the heat.
redfuneral

Showing 1 response by bcgator

redfuneral, I don't know where you are, but I understand your dilemma...somewhat.  I'm in Phoenix, and for some reason the room I chose in the house for my office doesn't seem to get as much AC airflow as some of the other rooms.  From June through September, my office can be uncomfortably warm.  I bought a Peachtree integrated, based on Class D amplification, specifically for summer use so that I could enjoy music without adding to my heat problem.  I'm very happy with it and now use it year-round (I also have an Audio Research tube integrated but don't use it).   I'm no engineer so I can't give you the technicals, all I can do is echo what others have said - it runs cool, sounds great, and takes up very little space.   Your friend steered you in the right direction with the Class D recommendation.