How much Power do speakers really use ???????

Pbb, my statement was applicable to any system of any power level, as it did not state any defined number of watts. Even high power amps are not played beyond a few watts nominal at moderate listening levels. At peaks, they use more. At higher listening levels with medium efficiency speakers, even high power amps can clip during dynamics, due to the nature of the db scale. If the speaker is around 90db efficient, and you listen around 90db, then you are only using one or two watts nominal, whether your amp is rated at ten watts or 200 watts. The rest depends on the ability of the amp to handle the dynamic peaks into the speaker load provided. In a situation where the dynamic peaks are 15db higher than that 90db average listening level, you require 32 watts above the average power required for that. That is for the 90db efficient speaker that I described above, and listening at the 1 watt level. If you have that 90db speaker and are averaging 8 watts listening level(~99db) then to handle a 15db peak, you would have to supply 256 watts to handle it. If you had a 18db peak, you'd need 512 watts.

Regarding my personal system performance values, I specified that it was my system, not theirs. My system can handle a 90db average listening level with less than 1/10 watt, and can achieve 15db peaks with about 3.2 watts.

Though the following is oversimplified, it's what I use when thinking about this issue.

I use a speaker with an 89dB/w sensitivity (and ignore how it was measured). I assume that peaks on the order of 15dB must be accommodated (a figure I remember for the human voice, one of the most demanding instruments). One watt will provide a listening level of 89dB and the peaks will require 32w (with a doubling of power as 3dB). Therefore these speakers require the following:

dB---w------peak w
80---.125---4
89---1------32
98---8------256

Using this as a ballpark, my 8w SET into 89dB/w speakers should be capable of about 83dB (.25w with 8w peaks) at one meter. My listening position is twice that, so somewhere around 80dB would be right (neglecting room effects - and my system is in a really small room). Since I listen exclusively to classical music and nearly always to small ensembles and solo instruments, this level suites my listening habits just fine. YMMV

For most applications...a quality 40 or 60w amp will suffice...and be able to drive even difficult loads to surprising levels of volume...I heard Maggies on a 40w Rega at my local dealer...and it sounded good....granted...if you want to "rock the house" or get evicted...you might need more juice...Im no expert...but even doubling your power is a marginal improvement...to really hear a gain...a factor of 3 or 4 is necessary...others will provide more technical answers...but unless you have a very large room with very inefficient speakers...I wouldnt worry about...

All of it!

I have compared the Cello Grand Masters (96db sensitivity) driven by one of their Performance amps which puts out about 1500 watts into this speaker, vs. a bridged pair that puts out about 6000 watts (per Cello). The difference was quite impressive.

You can NEVER have too much power!

Richard

Let's say you have two amps - one at 50 wpc and another at 5,000 wpc - with identical speakers and listening rooms. If you play both at a certain volume level, say 80 db SPL, both amps will provide the same power. However, during transient peaks, BOTH amps will clip. The 50w amp may distort at clipping while the 5,000w amp will recover much quicker where you would not notice the discontinuity. That's one rationale for mfr's pumping up the amp power - to tackle clipping.

So, the best way I can answer the questions is just how much quality you want for a particular listening level. You can get there with a 2 wpc SET as well as a 600w monoblock; "depends" is the answer - because a particular SPL level is dependent on room size, speaker sensitivity and physical comfort, etc. but the quality comes from both the electronics and the power capability. The SET uses its ability to produce a symmetrical waveform to recover from clipping while the SS beast uses brute force.