Is there such a thing as too much power?

Atmasphere, Is there a way to determine an amplifier's lowest point of distortion apriori or is an empirical issue?

If the specs are published, its easy, if not, a distortion analyzer is handy.


But as I mentioned, with most amplifiers this is about 5-7% of full power. Having unlimited power is great, but the practical issues around that are profound. If you need that power because you have inefficient speakers, thermal compression will prevent you from ever playing the system all that loud and getting the dynamic contrasts right. One problem that is epidemic with higher powered amps is poor application of loop negative feedback, owing largely to inadequate Gain Bandwidth Product. This causes such amps to sound harsh due to higher ordered harmonic distortion.


This is why efficiency is important in loudspeakers, and there is no reason why a speaker has to trade off anything if resolution is a higher goal. The speakers I'm running at home are 97.5dB, the first breakup of the midrange driver is at 35KHz. So its very fast and smooth. On such speakers you can use lower powered amps and still achieve sound pressures well over 100dB.

Can you ever have too much money , sex and stereo equipment ?

Doesn't SPL also depend on listening distance and room acoustics? So, if a speaker is 90 dB/1 watt at 1 meter and you sit 2-3 meters away from the speakers, then what you are hearing is 87 or 84 dB.  So, if you want to listen at 90 dB, you would need 2 to 4 watts, or more. So theoretically, a 40 to 50 watt amp capable of low distortion should do given transients.
If you want to pound your ears into oblivion, say starting at 105/102/101 dB, then you would need 16/32/64 watts using the above proportions. So, transients could demand 160/320/640 watts to keep it sounding "more live"?
So, for really loud music, a really powerful amp may come into play.

I typically listen to music at under 90 dB at more than 2.5 meters from speakers so a lower power low distortion amp should do. My amp, a Hegel h160 does nicely but it is over kill for my speakers, Focal 807Ws which were less than half the price. The speakers also do well with a really inexpensive class D with of course less quality than the Hegel. This little class D does seem to sound better in some ways to other AB amps under a grand I have tried. Depends on the level one listens, the Hegel and Focals work very well where cheaper alternatives would do for many.

I like stand mount speakers but if I were to go with a floorstander, I'd like to try Tekton Lore Reference. At 44 lbs, their doable.  At 96 dB, a smaller amp or tube could do. I do stay away from low sensitivity speakers as a rule seeking something around 90 dB.  Other speakers are Triangle Zetas for desktop. Less resolving, a bit more sibilant than Focals, less bass, but they do nicely as well. Don't even need a sub to enjoy them both though a sub can fill in the basslines.  Other very efficient speakers I have not heard , Zu speakers seem to have a following as do others.  Choices.

back in the 70's and 80's, stereo review reccomened that you buy the most watts you can afford! but then more watts could be bad watts! this is what was bad about the 'phase linear amps'!! a lot of watts but poor safety features!! my phase linear 400 fried my speakers with 'dc' current!!

Hi @agwca ,

It is not true. Every particular room has the parameter Critical Distance:
https://en.wikipedia.org/wiki/Critical_distance
"Critical distance is, in acoustics, the distance at which the sound pressure level of the direct sound D and the reverberant sound R are equal when dealing with a directional source. "
For typical listened room critical distance can be just 1-2 meter. And Critical distance is different for different frequencies.
If the distance from the speakers is longer than Critical Distance the sound pressure remains similar to sound pressure on the Critical Distance.
http://journal.telfor.rs/Published/Vol2No2/Vol2No2_A6.pdf

Regards,
Alex.