Is the most efficient speaker the best speaker?

Is the most efficient speaker the best speaker -- all other things being equal?
In my opinion NO
"...--all other things being equal?"
Not bloody likely.
It depends on how much power you have. If your amplifier is a 2A3 SET I would say yes.
All things will never be equal. If the sensitivity is above 91dB, things are pretty good. 95dB and above, they can be driven even more easily. However, I love the sound of Maggies, 86dB sensitive, and Legacy Whispers at about 95dB sensitive, and some horns at 100dB plus, and have heard many efficient things which made my ears bleed. Thus, the bottom line is how well matched your amp is to your speakers, regardless of sensitivity. Jallen
NO. Still too many variables. Otherwise one technology would have won out long ago and that has not even come close to happening with any piece of equipment. Think it through.
I think with all other things equal, then I say yes it is best to have high efficiency speakers so the amp can cruise along in an effortless mode and for the right solid state designs class A all the time.

why not?
Many varied factors come in to play. A well designed high efficiency speaker has the inherent advantage of increasing the pool of usable amplifiers. This opens the door for the inclusion of low power(high quality) amps such as SET,DHT-push pull, first watt etc. These types of amps with an appropriate speaker can sound fantastic. A good high efficiency speaker in general tends to be very dynamic and immediate even at moderate/lower listening levels. Just as with the less efficient speakers, some are better implemented than others.
Is the most efficient mode of transportation the best way to go?
Maybe yes, maybe no. But SETs are the best amps, and the first watt sounds best. So you're going to need efficient speakers, if you want the best sound IMHO.
I've heard amazing systems with 3 watt flea amps + Klipshorns

and I've heard amazing systems with 1000 watt monster amps and 83db inefficient Apogees

it's all about synergies but how you get to the sound you like can take multiple paths
All other things are never equal.
My experience has been the opposite, but the answer to your question is no. My Soundlab speakers are very in-efficient, but are the best sounding speakers I have owned.

The key is the right, properly matched, amp and speaker combo!

No way to say one speaker will sound better then another based on efficiency only.
Ptmconsulting, that was very well said, and two good examples. Proper amp/speaker matching is a fundamental key to sucessful system building.
Keep in mind we listen to a system not just a speaker, source, cables, amp etc. Also we all have different personal tastes and expectations. So while I prefer efficiency even when using higher power. Others may prefer a stat or dynamic driven with hi power.
I think the OP is asking a hypothetical question
Not to mention personal preferences. Both in what aspects of music you listen to and your musical preferences. My own prefs lean to high eff, in part because of some of the great small power amps that can be run with them. Cost was certainly a factor too (though you can have megabuck or inexpensive systems with either set-up)
Right now the highest efficiency speakers are for the most part, horns. Most horns have more reactive drivers due to the fact that they employ greater precision in their voice coil gaps. This extra reactive nature tends to mess with amplifiers of lower output impedance, particularly those that employ a loop negative feedback loop- thus the idea that horns can be 'shrill' or 'honky'.

Horns also usually prefer an amplifier that makes constant power at all impedances (or at least *tries* to) rather than constant voltage. More info is at this link:

So now we see that the idea of 'all other things being equal' taking on additional meaning! IOW you must be comparing apples to apples, so the other speaker of lessor efficiency should also be a Power Paradigm device. Given this constraint, if the higher efficiency speaker indeed is as revealing, has the same bandwidth, images as well, etc., then yes, the greater efficiency will be an advantage- you don't need as much amplifier power to make it go.

Since by definition we are talking about horns here, this is an advantage because the conversation makes no sense for the reasons I outlined if you don't also include tube amplifiers. The simple fact is that tube amplifier power is more expensive than transistor amplifier power. If you want realism (an orchestra can hit peaks of 115db to 120db), the ability to do this in a relaxed way without strain or harshness is then within grasp. It is simply not possible in most rooms if the speaker has low efficiency- too much is required of the amplifier!
Atmasphere is absolutely right. Horns rule. Lower power requirements equals more headroom and better dynamics.
Put your dollars into amplifier refinement rather than raw power. Quality over quantity.
Even speakers with efficiency an of 100 dB/W in a typical setting, will require about 200 Watts per channel to achieve 120 dB. One would have to have an extremely large room to adequately contain 120 dB with any semblance of scale, and require much more power in such a room than the 200 Watts per channel suggested above. Such power levels from tubes come at quite an initial cost, continuing costs, and some inherent technological considerations. Most people have neither the space, disposable income or even feel the need for such a luxury. Please don't get me started on the consequences of having to listen to horns in the first place.
And, they're off and running. . . Again.
Is it really necessary to achieve potentially hearing damaging levels of 100db and higher to fully enjoy one`s home audio system? I don`t believe people have to mimic ultra high and uncomfortable sound pressure if they have a reasonably quality system with very good musicality and resolution(and want good hearing a few years down the road).
Charles1dad, with all due respect to Atmasphere, I'm confident that he was only referring to intermittent peak levels. On the one hand, I do agree with him that being able to replicate absolute live levels is a good thing, on the other hand, I agree with you, in the big scheme of things it doesn't seem like the highest priority for most of us.


Are you saying that an amplifier will have to have fixed current to sound good on horns ... ?

So any amplifier with transformers should work IYO ..

Is it really necessary to achieve potentially hearing damaging levels of 100db and higher to fully enjoy one`s home audio system? I don`t believe people have to mimic ultra high and uncomfortable sound pressure if they have a reasonably quality system with very good musicality and resolution(and want good hearing a few years down the road).

-06-24-11: Charles1dad

Hello Charles1dad, IMO, usually speakers that lack dynamics and or have uneven power curves tend to sound at there best "loud" ...

For the most part all amplifiers tend to sound there best when run at no more than 33% of rated output, we need a lot more power than most would think to recreate live ( not SPL ) but realism of sound ...

The interesting thing to with regard to using speakers that offer an amp an easier ride to fixed current, is that it seems to be easier to make such a speaker with a steady low impedance and hence lower efficiency, than it is to do with a speaker with a higher impedance and hence higher efficiency.
High efficiency speakers may(or may not) be more difficult to implement sucessfully, but fortunately there are enough of them available that it`s a viable option for many. They sure work for me.
I'm glad they work for you.
All other things are never equal so its a useless question unfortunately.

More efficient speakers are more efficient and that's about all you can say about that.

Most portable electronics that operate out of necessity on low power are very efficient. DO they all sound good?

case closed.
Some times one can use the basis of "all other things being equal", but I don't think it works at all for loudspeakers, not for the time being anyway.
All the speakers that I have owned and liked best have been sealed and they are less efficient than most others. To my ears a sealed woofer gives the best bass of all other designs.
I haven't read all of these post, so it might have been answered...The answer to the exact question is yes.... In theory. If all things are totally equal except for sensitivity, the two speakers will sound identical except in the area of dynamics. The more sensitive speaker will be more dynamic. Next... This is impossible
I've read though the post... The op says "All things being equal" no debate on horns vs planars... Two identical horns, playing exact frequency curves, playing exact impedance & phase curves, playing the exact music... Or two exact matching planars or two exact matching dynamic drivers.... ALL THINGS BEING EQUAL, The more sensitive speaker will be more dynamic... The answer is Yes.
...And allow more noise in.
06-24-11: Timlub
I haven't read all of these post, so it might have been answered...The answer to the exact question is yes.... In theory. If all things are totally equal except for sensitivity, the two speakers will sound identical except in the area of dynamics. The more sensitive speaker will be more dynamic. Next... This is impossible
06-24-11: Timlub

Will have to disagree more sensitivity does not mean more dynamics...

Mapman`s analogy ignores that obvious fact that those portable devices are built to a price point and meant for very affordable(cheap!) entertainment purposes. The truth is within all speaker catagories there exist a hierarchy of performance. Some low efficiency speakers are wonderful and some poor sounding, same with higher efficiency models.

The goods news is there`s room in high end audio for us all. Now on the other hand, tubes vs solid state....
Well, I suppose if we were to take this somewhat academic question literaly, both speakers would be equally dynamic and equally capable of the same level of noise rejection, and equally capable with the same amplification.
I have been reading this thread with much interest. I greatly respect Ralph/Atmasphere and have always learned from his posts and others on this thread.

I must say my experience flies in the face of saying a low efficiency speaker can't play to sound pressure levels with as much ease and scale as a horn speaker with a nice quality tube amp.

Well, I have owned horn systems such as the Cain & Cain IMBEN with several high quality SET and other types of tube amps. In addition, I have owned 92-95 db efficient speakers from Silverline paired with tube and SS power amps rated up to 300 watts per side.

Now I own Soundlab M1 speakers and drive them with a 600 watt per side Sunfire Signature SS amp. This amp cost me $1500 used and new they were $3700 or so. My current rig plays to db levels that are well over 100db with an ease and scale I have yet to hear in any of my previous systems. My Soundlab speakers are only 87db efficient with impedance swings from 2 ohms up to near 40 ohms. Yes, they are hard to drive!

But the scale and ease to which this system plays is amazing to me.

So my experience is that large ESL speakers with a very powerful SS amp can certainly match or exceed the sound pressure levels and scale/ease of a horn system. No need to spend a lot for the right amp either. Worthy amps like my Sunfire can be had for under $3500 used.

Ralph is correct that a nice horn/tube amp rig can also soar in the manner he states. I agree 100% with that.
Hard to beat mid efficient speakers , it's the best of both worlds .
I purposely kept my question general in order to let let real world considerations bump up against the hypothetical. Of course "all other things being equal" doesn't exist -- except in any one particular system -- but interesting and useful information has resutled. Thanks for all your responses. Carry on.
How Dynamic is an 83db sensitive speaker with 50 watts? and how dynamic is a 93db sensitive speaker with 50 watts?
If absolutely everything was identical, the 93db speaker is not more dynamic? Right. Wes, I've heard you make some outstanding well thought out arguments in the past.
Again, the BIG STATEMENT, "All Things Being Equal".
My current speakers are very Dynamic and 86db 4 ohms, but they aren't dynamic with any amp. In the theory above the more sensitive speaker, even when it is only sensitivity that makes the two speakers different, the 93db speaker would be More dynamic without question.
The most efficient (sensitive) speaker primarily benefits the lowest power amplifiers... is the lowest power amplifier the best amplifier?

If so, then what would be the purpose of manufacturing higher power amplifiers and less than the most sensitive speaker?

Other Things are not the only things that are never equal.
The answer has to be yes, if all other speakers were connected to a 5w tube amp.
"The answer has to be yes, if all other speakers were connected to a 5w tube amp."

No doubt high efficiency is the way to go with a 5 watt tube amp. No arguments there.

However, the most efficient high efficiency speaker still may not be the "best", so the premise as stated still does not work.
Never underestimate the evocative power of the facile.
Yes Timlub,

Sorry i had misread your response, all things being equal and exact it will have more dynamic range...
To the OP's question as stated: yes.

To my ears, only high-sensitivity systems really "breathe" and allow the use of low-powered, more refined amplification without compromise. Low-sensitivity speaks sound as if a wet blanket has been draped over them, comparatively speaking (ahem).

But, to each his own.
Triode needs to hear better non-flea tube amp powered systems.
They do exist!

I also like SET amps and high efficiency speakers as they can sound quite good also.
"But,to each his own"
Triode , words of wisdom. The low power amp/high efficiency combination seems to more sucesfully present the flesh and blood, living breathing presence that`s so convincing. This ability to consistently create such realism is what pull me over to this genre.(is it the much simpler circuits and fewer parts?). Trumpets,pianos,saxaphones and human voice is simply much closer to what I hear at live performances, the palpable reproduction is stunning at times. YMMV.
These kind of discussions would have more weight if we were to quantify what is high sensitvity, medium and low ..

A horn speaker with a sensitivity of 100db/w/m being driven by a 20w SET, will have far less db gain and dynamics when compared to a planer speaker with a sensitivity of 86db/w/m being driven by a 200 watt amp @ a listening distance of 15 ft.

Weseixas, basd on your example of the two systems above, the horn/SET 20watt wouuld have much more available headroom (dynamic reserve)than the inefficient system. At 15 feet(roughly 5 meters) to achieve a sound level of 94db the horn/SET would require 4 watts, the planer/200 w system would need 128 watts. 5 divided by 20 is a much smaller % of available power rhan 128/200w, thus far more reserve headroom for the higher efficiency system.
Best Regards,