Riddle me this...

The answer is a toughie. I think it comes down to marketing. Despite what a person hears the wattage rating is kind of like horsepower. Lots of speakers are in the 87 to 94 dB 1W/1M class which means they are wasting power as heat rather than transducing it into "sound";ie pressure waves. If that is the case it is easier to "kick" the speaker with watts and produce what many buyers perceive as acceptable loudness. However, the notion of horsepower under the hood also comes into play. Actually to reproduce the transients in musical signals without waveform distortion, compression, etc. would require something on the order of 10,000 Watts. Buyers feel more comfortable with an amp that delivers a couple of hundred watts rather than 50. Enter the concept of marketing. A buyer feels just plain better with more "horsepower" in his amp. And, watts are cheap, but more watts don't necessarily sound better. The original Classe amp produced 20 solid state watts of pure class A performance, sounded very good for a solid state amp, and ran so hot you could have used the heat sinks for waffle irons.

It would be better to have loudspeakers in the range of 98 to 105 dB 1W/1M to take advantage of the simpler circuits in solid state design, vacuum tube amplifiers with only two output tubes in push-pull, or better yet a Single Ended Triode amp that does not require phase splitting of the signal anywhere in the signal path. I think Nelson Pass is doing single ended solid state amps, but haven't kept up with the state of the solid state art. Nelson is, in my opinion, an innovative original thinker. Plus he is a heck of a nice guy. There are lots of tube SET amps that accomplish lovely music reproduction and infuse a kind of life into your recorded music, often quite literally taking your breath away.

I agree that higher efficiency speakers open up a lot of doors in terms of amplifier selection. To attain high efficiency though, one must sacrifice low frequency extension in a sealed design or poorer transient response / less control by going to a vented design. Horn designs would have to be HUGE to get deep bass out of them. Going that route would once again produce a sacrifice though, this one being bass definition and tonality. As such, you have now traded in one sacrifice for another.

Besides all of the above, i have run into more than a few high efficiency speakers that really did NOT like being fed any type of power. Get them up to the point that things are beginning to crank and distortion and compression set in quite rapidly. I'm not saying that all high efficiency designs do this, but that most designs work best within a limited SPL range. Sean
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How wonderful it would be if all speakers were easy to drive and possessed of high sensitivity, and less power would get us all by. But it seems to me that what some folks are conveniently overlooking in their romantic reveries about the 'golden age' is that most speakers partnered with the lower-powered amps available back then simply could not deliver either the frequency or amplitude bandwidths along with the low distortion, even dispersion, and flat response that we demand from modern speakers. You can't have it all in a speaker design, and I for one will gladly accept the 'moderate' efficiency of most modern speaker designs in exchange for their now-commonplace combination of neutrality, extension, high S/N ratio, smooth power response, dynamic range, and freedom from resonance and breakup effects.

I am not in this hobby in order to pursue any slightly fetishistic agenda pertaining to certain schools of thought concerning equipment design, comfortable nostalgia, or the self-consciously iconoclastic exclusivity of belonging to some tiny 'club' whose members are more discerning than thou. I just want to hear more of the music and less of the means by which it is reproduced. I am well aware of the general lack of correlation between rated amplifier power output and sound quality, but that works both ways - there are many audiophiles who, while professing agreement with that last statement as it applies to lower-powered amps, seem to take it as a matter of faith that there will be a (negative) correlation between sound quality and rated watts in the case of higher-powered amps. Untrue. Low power is no guarantee of superior sound, and high power is no guarantee of either inferior or superior sound. All other things being equal, if a higher-powered design were to envince no overall sacrifice in sound quality at low-to-moderate listening volumes or playing delicate music versus a lower-powered design, I would take the higher-powered option for its predictable superiority at higher listening volumes or with the most demanding material (disregarding for the moment such practical concerns as purchase price, heat production, power consumption, and size and weight).

If it were indeed true as some would have us believe, that there exists a low-powered amp 'sound' and a high-powered amp 'sound', then both of those supposed identifiably different 'sounds' would represent deviations from the truth, and as such the goal should be to engineer amps that don't impose those characteristic deviations or limitations upon the sound (within, of course, the hierarchy of real-world constraints alluded to above). If that goal can be met with greater rather than lesser available power, then there should be no reasons other than the aforesaid practical ones why that capability should not be offered.

And maybe that's just what has happened. Maybe when people talk of 'convergence', what they're really saying is that today, you don't necessarily need to sacrifice anything desirable of your 40w to get your 150w, practical issues aside. And if today's better speaker designs - which most audiophiles will agree are capable of superior all-around performance compared to just about anything comparable available 20 years ago - can make good use of that power, then it is entirely justified. I've lived happily with under 50w, and know I could have been happy with even less if I owned different speakers. But now that I'm in a house with a larger listening room rather than an apartment with a small one, I'm getting even better sound by using 4X the power, and can still bump up against the system's dynamic limitations if I so choose. To those who would advise me to learn to listen at quieter levels I say, I often do - but feel the parameter of amplitudinal fidelity is too often overlooked by audiophiles focused on other (also worthy) sonic qualities, or understandably compromised by various real-world restrictions. But to me, the problem of reproducing recorded piano at a realistic volume without difficulty is just as important as are the challenges entailed in playback which strives to optimize any of the other well-known audiophile wish-list qualities (and probably more important than many).

As Schubertmaniac's list makes clear, maybe we are not losing anything - even for the money (adjusting for inflation) - in today's relatively higher-powered amplifier universe, and really have nothing to complain about (especially considering the modern plethora of SET's available for those who want). It's just possible. And if true, then the seemingly irrefutable evidence concerning the minimal sales of the smallest and least expensive audiophile models (speaking now of conventional SS designs) is completely understandable, as is any manufacturer's decision to either drop or phase those models upward to a higher power plateau.

Sean- for that matter, can we have efficient FULL-RANGE speakers w/out lots of compromise? Compromise that we pay for elsewhere (i.e. amplification, active subs)? I think that the "speaker + sub" scenario typifies it: we need two separate speaker transducers to even APPROACH full-range reproduction. Or, we have to turn to giga$ speakers, some of which incorporate the "sub" part... which of course requires bi-amping at least. I.e. it's not only the watts in one main amp its also often necessary to have TWO amps, even if the one of the two amps comes with the speaker set (but we pay for it, don't we?).
Three of us experimented with a pair of Avanti -- trying to get "the last ounce" of sound out of it. The best result we could achieve required $20k of amplification + another 7k of branded speaker cable. Spare change.

And, what about the upper register -- the harmonics going beyond that 20kHz standard? How much of that can we normally reproduce through our speakers? Despite the wide-band electronics that are available & hi-rez sources, and s/ware that is supposedly available? Little, I bet...

It seems that the kind of reproduction we are driving for here is an excercise in inefficiency -- in a grand scale.

I'd like to put my 2 cents in regarding these last few posts, that have alot of merit in them.

Nothing is perfect, and we will compromise in whatever we get.Like Sean says, it takes surface area and power to move alot of air for high-SPL deep bass response. Like Gregm says, it takes speed and maybe even some unknown things to cover supersonic frequencies, which may affect the listening experience in yet unkown ways. Like Zaikesman says, there is becoming less difference between high power amps and low power, in terms of accuracy, and sound quality.

So again, it comes back to what each individual wants in their system. A person that uses single-drivers and low power amps, like myself, would be foolish to think that he's going to get 125db at 20Hz out of his system. It is not going to happen. Conversely, there are different sacrifices made when someone selects a system that will produce that kind of SPL/freq. As Gregm points out most full range systems require multiple drivers, maybe multiple amps, alot of gain stages, low efficiency drivers, volumetric efficiency sacrifices in the enclosures, possibly equalization, crossover distortions, longer signal path, etc. If these trade-offs are considered to be acceptible for the SPL and frequency extension desired, then that is a fine choice.

But, there is no free ride. You will make sacrifices that accompany your decisions. There are many who think that they can get the sound quality of a good low powered SET, from their Godzilla amplifiers, and this is simply not the case. There are some who think that they can get the SPL and frequency extension of a high-powered SS system from their SET's, and this is simply not the case, either. It is a "pick your poison" situation.

Of course, there are certain applications where there is no choice, such as sound reinforcement for theaters, or stadiums, or hard rockers who must play music at 120db. For all others there is a choice, as far as home reproduction is concerned. The choices made will ultimately define the capabilities of that system.

Unfortunately, the "hyping" of certain products by manufacturers, magazines, or owners, in an attempt to make others believe that there is no sacrifice to be made in owning that product, leads to less-savvy purchasers being mis-led into thinking that they can have it all. Nobody has it all.