How important is the efficiency of a speaker to you?


I went to an audio meeting recently and heard a couple of good sounding speakers. These speakers were not inexpensive and were well built. Problem is that they also require a very large ss amp upstream to drive them. Something that can push a lot of current, which pretty much rules out most low-mid ( maybe even high) powered tube amps. When I mentioned this to the person doing the demo, i was basically belittled, as he felt that the efficiency of a speaker is pretty much irrelevant ( well he would, as he is trying to sell these speakers). The speaker line is fairly well known to drop down to a very low impedance level in the bass regions. This requires an amp that is going to be $$$, as it has to not be bothered by the lowest impedances.

Personally, if I cannot make a speaker work with most tube amps on the market, or am forced to dig deeply into the pocketbook to own a huge ss amp upstream, this is a MAJOR negative to me with regards to the speaker in question ( whichever speaker that may be). So much so, that I will not entertain this design, regardless of SQ.

Your thoughts?

128x128daveyf

@daveyf  : Yes, maybe me.

 

@unsound   " speakers designers have to choose what paramters and associated compromises combine to best meet ultimate design goals. Some if not most of the best measuring loudpseakers have lower impedances, and ergo lower sensitivity. There are a bountiful number of well designed amps that can handle such loads with minimal consequence. "

In total agreement with you.

 

R.

 

Again

Speaker sensitivty alone is not an indicator of quality or sonic virtue in loudspeakers.  I can think of other values that might be related to sonic virtue, such as widely varying impedance (in a passive design), high distortion, limited dispersion, inconsistent dispersion across the audio band, etc, etc.  High efficiency is simply an engineering choice made, not an evolution.

Brad       

@rauliruegas I think we need to be more clear as to what we are discussing when it comes to lower sensitivity. There is little question that a lot of great speakers are in the less efficient camp, meaning that they are not in the 100db/w mode, but closer to 85db/w etc., These very same speakers may drop down into the 3-4 ohm load in the bass, which might present a more challenging load to some amp designs, but like pointed out, with a sufficiently beefy power supply, will still work fine. These are not really the speakers that I am talking about here ( not sure about others), instead the designs that are on the market ( or have been on the market) that drop down to 1 ohm or less, and as such, are now presenting a very difficult load to the upstream amp. There are not too many speakers that this applies to, but you might be surprised by how many it does. Plus, many of these designs are from well known ( and respected) manufacturer’s, like the ones in my OP.

@lonemountain   While I would agree that sensitivity alone is not a indicator of quality or sonic virtue in loudspeakers, it certainly is an indicator as to what one can expect as to choosing an amp that will work well with said speakers. As such, the number and type of amps that will work is now significantly diminished, and as pointed out above by atmasphere, said amp will almost certainly NOT be working at its best. It also pretty much removes certain types of amp designs...mostly in the tubed genre.

@lonemountain wrote:

When you say that efficiency is not the most important aspect of performance ...

I wrote it’s "not the only" important aspect. These last ~15 years I’ve avoided low efficiency speakers as anything I’d consider buying (with the exception of seriously considering at one point larger and active ATC models, in particular the SCM150ASL Pro’s (and ultimately the SCM300’s, had economy allowed)), but efficiency as a standalone parameter isn’t as much the true indicator vs. what it leads to design- and size-wise, and so it’s really the other way ’round: the designs I prefer are mostly horn-based and large, and therefore, in effect, high to very high efficiency as well. It’s not that I can’t enjoy the sound of many a low. eff. design, quite to the contrary, but I’m simply pursuing a different route with different strengths sonically compared to what smaller, more inefficient and passively configured speakers can deliver.

I disagree that efficiency is the "preferred route" in achieving lower distortion, improved dynamics or increased bass. There are so many other avenues to these features.

Fair enough, but coming down to it we’ll have to disagree on this one. Yes, there are other avenues and areas of importance here that can make a low eff. package sound indeed very good in named areas, but when higher efficiency enters the "equation" to boot (again, not as the only parameter as anything worth considering) the significance in performance - to my ears and sensibilities - is not trivial.

ATC is a notable exception here, to an extend, in that their engineering prowess in driver development and overall execution is on another level compared to most lower eff. speaker manufacturers (and thus, and this needs to be stressed, they’re hardly representative of the low eff. segment of speakers). Active config. only adds to this advantage. The SCM150 and SCM300ASL Pro’s - that I’ve auditioned quite a few times - are excellent speakers in their own right that I could easily live with, and yet a large horn-based system (not least actively configured) does something else both dynamically, with regard to ease(!), scale, presence, immersively, viscerally and bass delivery that you’ll have to experience to fully understand and appreciate.

I did not say that low eff. designs avoid the limitations of poor efficiency simply by adding more power. There may not be limitations of lower efficiency designs, depending on your goals. Or there could be limitations of a high efficiency design.

Different contexts will have things in variables, yes, but getting a true bearing on a more complete wallop and significance of uninhibited dynamics, low distortion imprinting and smooth, effortless bass prowess at more than moderate SPL’s and shorter listening distances will require setting a different benchmark; to some these very aspects aren’t main priorities, let alone secondary, but to others they’re quite another connoisseur matter and will necessitate measures that goes beyond smaller, passively driven and low efficiency speakers.

I think the whole array of solutions are far more complex than high or low efficiency "spec" on a spec sheet. Whether something is 92dB 1w/1m in a loudspeaker gives you zero information about quality when compared to a 86dB 1w/1m spec.. You only know the designer chose to chase efficiency (probably for more than one reason). Intended application is everything..

Chasing efficiency in itself would seem crude, but let’s make it actual high efficiency to begin with if we really want to refer to it as such; my understanding of high efficiency, all along, has been a sensitivity from 95-100dB’s on up. Few designs really accomplish that, and if you intend to have a fairly uniform and controlled directivity pattern at the vital crossover(s), not least crossing low enough to avoid the central midrange while maintaining sensitivity all the way down low to the 20-30Hz region, then you’ll have yourself a large sized package that can really show its mettle with the parameters referred to earlier.

Some lower efficiency designs can achieve lower distortion in the driver, or can extend low frequency of that driver or both. Or your lower effieciency design may improve cooling and power handling without extending voice coil length. I guess to me its like horsepower tells you zero about the performance of a car. There are so many different options available to a skilled designer that focusing only on a high efficiency design is not wise, again, depending on your goals. I favor lower distortion myself, I want to hear more of the fine details, the reverb tails, the room sound, etc. If I can have lower distortion that reveals more of that fine detail in exchange for a larger power amp, I’m in. That’s the trade off I am talking about. And I’ll stick to my guns on this one, you cannot have it all.

And this is where we are ultimately disagreeing. Within the design differences inherently at play here I do believe we can more or less have it all; care taken with a specific design is not limited to low efficiency dittos, and if you’re willing to go the distance and let size and physics have its say, it means upping the potential of such designs even further. No, I wouldn’t cram speakers that large in small rooms, but contrary to common belief they can be implemented excellently in moderately sized listening spaces - not least actively.