Understanding Amplifier Power Output Specifications

Don’t base an amplifier’s quality just on its wattage output

@mulveling wrote:

... When dealing with say L/R channel imbalances, you can certainly notice down to a third of a decibel, at least.

Indeed. My Xilica digital crossover/DSP has gain adjustment in 0.25dB increments, and occasionally I wish 0.10dB increments had been available.

@2psyop wrote:

What is you experience with high power, high current amps ? Do your speakers sound better with more power? At low volumes, in a small or medium sized room? Do you think the quality of the music is dependent on higher powered amps?

My previous, passively configured speaker setup (104dB sensitivity) had a 30W class A power amp delivering substantial SPL output with ease, where my current, actively configured speaker system is powered by a combined 2,350W per channel with a sensitivity range of 97, 100 and 111dB’s (subs, midbass and HF/MF horn). Even with high sensitivity in both speaker cases the latter, active scenario lets the prodigious power wallop at hand here shine through at moderate as well as very high SPL’s, but that’s just speaking of the perceived power envelope in different contexts. Perhaps more relevant would be comparing different power scenarios via one and the same speaker combo and (preferably) the same amp brand/series, which I have, and with my current, active speaker system and chosen amp brand/series this has yielded a slightly more assured and fuller presentation with the more powerful iterations from the same series (even with a very slight difference of 575 vs. 625W/8 ohm). Rarely using more than 10-20W in my specific case this may seem an improbable outcome, but listening soon lets one know otherwise.

I’d say it is more the speaker than the Amp. I’m running only 30 watts of class A power into the Tannoys... (Sugden A21se signature)plenty of power! They are honestly the best speakers I’ve heard at low volumes...still sound full and I do not feel I have to play them loud, as it is still all there

I’ve destroyed several amps, melted binding,posts, blown tweeters, mids, u get that unclear muffle sound, then u fry a tweeter, nt from power, from NOT ENOUGH POWER, headroom, amps ability to produce the juice you want, when you use a little flea fart amp, or in my experience, anything under,250-300WPC RMS, even at medium volume, the amp may not be able to supply the current/power,needed for a crescendo, or a double bass section with lead ,bass, and rhythm guitar, all going forward with intensity,……many,amps will clip. In my 35+ years in audio, I’ve found the best results with min 250-300 W at 8 ohm and close to doubling in 4 and 2, which tells purchaser there is a stable power supply.

The lowest power monos I have are the Odyssey stratos maxed out , they are 200W at 8 ohm, and 375 into 4 ohm, while these are capable, they are very high current which picks up the slack, almost beer can size caps, etc etc, I hooked up my modded cerw vega D9 which drop down to about 2 ohm, new woofers, crossovers reworked, great mids and tweeter, these destroyed my previous receiver and amplifiers.

When I bought the Rotel rb1090, the gates opened, and a heavenly light shined my window, and the angels sang a chorus of Stevie wonder ,ac/dc, Helstar, which was crystal clear 1/2 mile away at my uncles driveway.

From that point on, nothing less than 300+ WPC rms

plus that headroom gives a open almost stadium, ease of playback ,no strain volume , at any level.
will never go back to flea fart and bunny queef receivers, amps.

its effortless, easy, and gives a sense of fluid, easy going, non fatiguing playback.

In the end, I was so sad one morning, saturday, no work, pressed power switch on my Rotel rb1090, and POP, flash, white smoke, small,white and blue flame shot up from the top cover vents, the inrush limiter had fried, only 15 months old.

went through a couple amps and monos since settling on my dna750 monos bought used in 2016 I think. Best decision I have made in a,long time.

650W 8, 1000@4, power supply not quite hefty enough to double down, but with 650 at 8 ohm, I’ve never heard a muddy sound, clip, strain, distortion,

pure goosebump overload.
even playing poorly recorded records, does sound as it is, poorly,recorded, but there is a subtle fix, or tone, which makes demo tapes and old boot live,recordings more listenable.

yes, having the headroom is essential for playback, if you like any volume at all, it will save you from clipping, distortion, strain. 
higher powered amps sound better, with class A being only exception. 
 

even in class A, I would not go below 250-300WPC,  just from lessons learned and life experiences with power amps. 
 

plus , if you decide to upgrade speakers, etc, you will have the backbone to drive most consumer speakers down to 3.5 - 4 ohm.

planar speakers and those 1-2 ohm,…speakers, best check with manufacturer. 
and use your ears as main guide, if you hear strain, or tweeter breaking up, Gary Moore’s guitar muffled in midrange, your pushing too hard. 
 

use ur best judgement, and FFS, drunkenness and volume don’t mix. 
 

my,speakers I use now, only rated at 250W,, they are,glorious, smooth, warm, and so clear, there are no,speakers when I sit for an extended listening session, when eyes,closed, you can not pinpoint where the speakers, sound is emanating from!

love it

I figured out a long time ago that less is better - amplifiers and other components with fewer parts sound better to me - better imaging, transparency and so on.  The less stuff a signal has to travel through the better.  High power means more parts.   I just finished building a Firstwatt F5 which is 25 watts per channel class A.  As you know Nelson Pass is designing these low power amps with as few parts as possible.   Speakers are Klipsch Forte which are something like 98 db sensitive.  But what you like is what matters.