What is your take on high efficient speakers vs. low efficient speakers?


Consider both designs are done right and your other equipment is well matched with the speakers.  Do you have any preference when it comes to sound quality?  Is it matter of economic decision when it comes to price? - power amps can become very expensive when power goes up, on the other hand large,  efficient speakers are expensive as well.  Is your decision based on room size?  I'd love to hear from you on the subject. 

128x128tannoy56

more than one way to skin a cat. It's always a matter of pairing of amp & speaker in an appropriately sized room. So IMHO, a practical way to approach it is:

1) what speakers that I love are will work well in this room?

2) what amps work best with that speaker? Cheers,

Spencer

@sbank 

 

+1 …. Eloquently said … point, set, and match ! ( in tennis jargon) 

I agree with Spencer. I've had low to high efficiency speakers and all have had their strengths and weaknesses. All could be made to sound good with matching equipment. That said, I usually come down in the high efficiency camp since I like mid to lower powered tube amps.

There are good and bad examples of all kinds of speakers with different attributes.  Assuming the speaker has a reasonably smooth and balanced frequency response, the efficient speaker has several particularly important advantages.  The primary advantage is that, at least for my taste, the very best amps are low in power output. I like tube amps, but, mostly those that do not use higher powered pentode output tubes that are used in large quantities to achieve high power, and even solid state amps seem to be better sounding if they are not extremely powerful (e.g., First Watt amplifiers).

The other advantage is that high efficiency speakers tend to have better dynamics because they will deliver decent volume without as much power being dissipated as heat.  That heat being dissipated in low-efficiency speakers increases the resistance of the electrical component, which means less current/power can be delivered; this is thermal compression that means the volume level does not increase in proper proportion to the signal level.  

+1 @larryi 

Your last paragraph sums it up to me…

Lack of dynamics (generally due to thermal compression) always brings me back to “HIGH SENSITIVITY LOUDSPEAKERS”

 

 

@larryi What would you say are the attributes of low efficient speakers?  Anyone?

A lot of my listening is at low to moderate volume levels.

In my experience, high efficiency speakers sound better at such levels, especially in the bass.  Low efficiency speakers seem to lose bass impact at less than high volumes.

There are many low efficiency speakers that are quite good sounding, but, that is despite being low efficiency--there is nothing favorable about that attribute.  For example, Soundlab electrostatics, Magneplanar planar magnetic/ribbon, Falcon LS3/5A small box speakers sound pretty good, but, because they are low in efficiency, they are more limited in the ability to use amps such as single ended triode tube amps or lower-powered pentode/tetrode tube amps like those employing the 6L6 tube.  Everything else being equal, I will take a high efficiency speaker any day over a low-efficiency one.

Most high efficiency speakers take advantage of very big boxes to deliver higher bass volume.  When stereo came along, it became harder to fit two big boxes in a room, which is why smaller, less efficient speakers were favored.  The use of transistors made it easier and cheaper to provide the necessary power for these less efficient boxes.  These practical considerations played a big role in low-efficiency speakers taking over.

 

@larryi Do you hear inherent distortion/coloration from the larger speaker enclosures in comparison to smaller enclosures? Is there, therefore, any overall effect on the sound characteristic?

 Everything else being equal, I will take a high efficiency speaker any day over a low-efficiency one.

I agree 100%!

Mike

I can see how it would be harder to control resonance of larger boxes.  But, many of the designs that employ heroic measures to control resonance tend to sound a bit sterile, lifeless and lacking in "weight" (thin and anemic sounding).  I have no idea if this is because of the resonance control or some other design choices, but, I will say that I don't look at ANY design choice as being dispositive of whether the sound will be good or bad and I don't rule out any speaker just because it is designed or built in a particular way.  I've heard some really nice speakers with big cabinets with thin, almost flimsy looking walls that have to be resonating--whether they sound good because of the resonance or despite it, I cannot say for certain.

@tannoy56 wrote:

@larryi What would you say are the attributes of low efficient speakers?  Anyone?

IMHO, compared to higher efficiency speakers typically incorporating horns or waveguides at least as hybrid designs (in conjunction with a direct radiating woofer/mids) or more radically as all-horns, a very general observation could be made that low efficiency, direct radiating speakers are less dense and present/direct sounding (paradoxically perhaps when being called 'direct radiating'), while also being dynamically more muted (and less lively overall). Low eff. speakers sometimes have an airier presentation, perhaps due to involving more reflected sound and having a more laid-back, less full sounding imprinting. Very good high eff. speakers have this "lit from within" and ignited quality that really makes music spark and come to life effortlessly, and the larger iterations have a fully immersive and physical yet relaxed presence to them that's quite addictive ones you get used to it.  

phusis,

Thank you for an excellent description of what is most prized about the sound of high efficiency systems, particularly, horn-based systems.  

While good design of such systems will ameliorate midrange "peaky" or "nasal" colorations, such systems do tend to be a bit less smooth in frequency response than better low-efficiency direct radiating speakers.  I hesitate to say this because so many people have heard grossly uneven horn and wide range high efficiency driver systems, and do associate such systems with such coloration, but I will say that such problems can be effectively ameliorated in better designs.  Still, I can see why such systems will not be to everyone's taste.  

What do you guys consider high efficiency or low efficiency?   MY main speakers are rated at 93.5db efficient and my office speakers are rated at 88db.

@tannoy56 wrote: "What would you say are the attributes of low efficient speakers? Anyone?"

Low efficiency speakers will give you deeper bass response for a given enclosure size, often dramatically so.

The obvious implication of the above is, low-efficiency speakers tend to have much higher "spouse acceptance factors".

As was mentioned previously, low efficiency speakers tend to have wider dispersion, this because designs which result in high efficiency (such as horns) tend to have deliberately narrowed dispersion. Whether wide or narrow dispersion is better is subject to debate, and imo depends on the room itself and other other considerations.

Some horns have coloration, which imo eliminates them from serious contention. At the risk of over-generalizing, I’d be wary of horns which have sharp-edged internal "kinks" and/or sharp edges around the mouth.

In general smooth frequency response is less expensive to achieve with low-efficiency speakers than with high-efficiency speakers. This is because there are inevitable tradeoffs in driver design, and some of the characteristics which contribute to response smoothness work against high efficiency, and vice-versa.

I’m sure there are other attributes of low-efficiency speakers which I have overlooked.

Imo amplifier + speakers + room = "a system within a system". Typically the room is the most expensive component, and the most difficult to upgrade, implying that the speakers and the amp(s) should be chosen to work well in that particular room as well as with each other.

Imo, ime, ymmv.

Duke

High-efficiency speaker manufacturer

I sort of think that 95-96 is at the low end of the range.  My speakers are 99 db/w efficient, and friend calls that medium efficiency (his speakers are above 112 db/w efficient.  It also matters how smooth and high is the impedance curve of the speaker.  I recall how one of the Wilson Watt/Puppy speakers was supposedly 95 db efficient (at a nominal 4 ohms, meaning some more realistically at 93 db/w efficient) which should have made it fairly easy to drive, but it turned out to be a very demanding and difficult speaker to couple with some tube amps.  On the other hand, the original BBC monitor LS3/5A (15 ohm version) which is rated in the low 80's as far as efficiency goes, couples well with even somewhat low-powered amps because it is a very easy load.  

@larryi wrote: "I sort of think that 95-96 is at the low end of the range. My speakers are 99 db/w efficient, and friend calls that medium efficiency (his speakers are above 112 db/w efficient."

Imo this is something to be aware of:

Very often the limiting factor for high-efficiency systems is the on-axis frequency response at high frequencies. And one way to get very high efficiency numbers is to use a horn whose pattern at high frequencies is very narrow, such that all of the high frequency energy is concentrated in a narrow beam, thereby maximizing the on-axis sound pressure. If the same compression driver were used on a wide-pattern horn, the same amount of acoustic energy would come out, but because it’s spread over a wider angle the on-axis PRESSURE would be less.

By way of analogy, consider a garden hose with an adjustable nozzle. The on-axis PRESSURE is higher when the nozzle is adjusted for the narrowest possible pattern, but the same AMOUNT of water comes out regardless of the pattern width. So too with horn radiation patterns.

Implied by this is the fact that an omnidirectional speaker system is actually putting out a lot more acoustic energy than we would normally infer from its "on-axis" efficiency.  So comparing efficiency (or voltage sensitivity) specs is not necessarily making an "apples to apples" comparison.

Duke

+1 @stereo5 

High and low efficiency values can be somewhat objective. Seems like the majority (in past conversations) consider high efficiency to be greater than 95db, and many consider low efficiency to be 89db or less. Where does that leave the 90-94db speaker?

@stereo5,

See chart below:

Mike

 
Sensitivity in dB = 112 + 10 log (efficiency)
 
 Efficiency = 10(Sensitivity in dB – 112)/10 
 

 

Loudspeaker data
Efficiency  Percent  Sensitivity
0.2        20 % 105 dB
0.1        10 % 102 dB
0.05       5 %   99 dB
0.02       2 %   95 dB
0.01       1 %   92 dB
  0.005     0.5 %   89 dB
  0.002     0.2 %   85 dB
  0.001     0.1 %   82 dB

 

105 dB is very efficient and 82 dB is very inefficient

@blisshifi agreed…

Except aren’t we talking sensitivity?

so 90-94db= “medium sensitivity “ lolololol

this is a great thread! i listen at low/moderate volumes and low powered set amps and high efficient speakers move me the most. 

Unless you are using a class A amp ( The heat of the output tubes or transistors ), there shouldn’t be much of a difference, right? When I had tube mono blocks, I’d swear you could make tomato soup on one and a toasted cheese sandwich on the other.

 JD

jmolsberg's avatar

jmolsberg Welcome to the  "neighborhood " - same with me - low power amp and high efficient speakers. 

In my opinion, there is too much hype around what most have not seen)) ... In fact - it is difficult to list a few really good and at the same time well-known high-performance speakers (over 100 dB watts meter) ... Such speakers have a short stroke - they can't scoop up and throw a lot of air at you - that's bass limitation... A mouthpiece or a big cabinet is an extremely tricky thing - manufacturers prefer not to get involved.

My idol is Aries Cerat Symphonia ...Lowther tp1... possibly the top Oma models (I didn't hear them in a nice quiet large room)...

Voxativ, Auditorium 23 - hypertrophied and at the same time skinny sound...

Of course, the size of the room and its coverage are fundamental here ... (as well as the type of music you prefer).

The very formulation of the question is not entirely correct)) ... it is obvious that "shoes" need to be bought according to their size.

High sensitivity - this is for experienced gourmets - they will figure it out themselves. If the choice is before a beginner - choose everything in the middle - you will not be mistaken. (previously, the system you want to buy should be listened to in a similar room to your favorite music ... find an audio veteran and copy his system) ...

I’ve tried some relatively high end speakers (in my world) with low sensitivity …

B741 SS……then floor to ceiling line arrays …then others I can’t remember them all.

 

While some had their attributes …(actually only the line arrays) none had the startling dynamics and realism of high my sensitivity horn speakers.

We all like different things. My freind (and neighbor) loved my low sensitivity speakers, he would comment on how “smooth” they sounded.

To me that’s code for “unexciting” lol 

 

I agree with audiokinesis. Although a speaker's sensitivity should be considered when matching them to an amplifier, it would be wrong to use the sensitivity rating as an indicator of quality. Many speaker designers opt to trade high sensitivity for deeper base production, especially in smaller enclosures. Remember also that generally a tube-powered amplifier will seem more powerful and play louder than a solid state amplifier of the same or similar power rating.

I'm on my third pair of Magnepans.  Sensitivity is rated at 86db - very low efficiency.  

I've owned Altecs, Advents, KLH, Klipsch, Nola, Allison, B&W 802's which cost a fortune. 

Nothing comes close to the Magnepans.  

I'm on my third pair of Magnepans.  Sensitivity is rated at 86db - very low efficiency.  

I've owned Altecs, Advents, KLH, Klipsch, Nola, Allison, B&W 802's which cost a fortune. 

Nothing comes close to the Magnepans.  

I like small and functional. Therefore I tend to not covet full range high efficiency speakers which will always be larger and therefore also more costly.    There are really only a handful of high efficiency speakers I would ever practically consider given the options.  Most people would agree which is why good quality lower efficiency designs are so much more common than the alternative these days. 

Hello TANNOY56!  If you have Tannoys, you're used to high efficiency speakers. Three cheers for you! You can use those gloriously liquid low watt tube amps and annoy the neighbors. Imagine a 104 db sensivity speaker vs a 94 db spl and a 84 db spl speaker. Have you ever watched the dancing meters on some bit of audio gear? Have you noticed that a 10 db difference doesn't sound like a big deal? To play as loud as the 104 db speaker, the 94 db speaker needs 10 (ten!) times the power; the 84 db speaker (the Maggie LRS comes to mind - I love them) needs 100 (yes, one hundred!) times the power for the same loudness.  If you music is cruising along at four watts, the 94 db speaker will need 40 watts, and the 84 db speaker will need 400 watts (!) for the same lloudness. Efficiency is a wonderful thing. Think aboout amplifier headroom. My maggies are driven by a 400 wpc amp. They sit atop a pair of high efficiency speakers driven by a 9 wpc 300B tube amp.

There is very little difference in the sound. Why use more electricity than necessary? Why heat up the parts in the amp and shorten their life? Get the picture? I very much admire Nelson Pass. I have two of his amps. They sound great. And they heat up my TV dinners. Ouch! Environmentally . . . ?  Happy Listening!

 If you music is cruising along at four watts, the 94 db speaker will need 40 watts, and the 84 db speaker will need 40 watts 

For many listeners typical/average listening volumes fall in the 70-80 db (C-weighted) range. A 104 db sensitivity speaker is probably using 1/100 of a watt. The 94 db speaker roughly 1/10 watt. Either way, minuscule power draw from amplifier at very reasonable listening SPL.

Charles

 

The beliefs around speaker efficiency is sometimes silly. All those numbers mean is how loud a speaker is when driven with 1 watt of power. A 3 watt "flea" power amp putting out 2 watts with any speaker, will produce the same level as a 400 wpc monoblock delivering 2 watts into the same speaker. 

Then again, some people have the erroneous belief that more power sounds better. If that was the case, the very low powered amps would sound terrible. 

My take on this is, that if you are not stuck with worrying about keeping efficiency then you can use components and crossovers that may provide a flatter frequency response without compromise. Often you have to compromise the response to keep the high efficiency. Having said that I think there are good loudspeakers in both camps.  

y’all understand distortion counts as output..in the overly simplistic efficiency measurement…. right ?

You'd want it to be as high efficiency as possible, but if you like the sound of the low efficiency speaker the best, then you get the gear to drive it.

y’all understand distortion counts as output..in the overly simplistic efficiency measurement…. right ?

Overly simplistic? Nah , I think people recognize that it is just providing a generalization of the lower power demands of higher sensitivity speakers. People get that. Very little distortion concerns if a 5 watt amp is only providing fractions of 1watt of power at desired SPLs. Well within the low watt amplifier’s sweet spot.

Charles

@czarivey Sure, more music more noise. More filtering less noise and less music. You have to decide what bothers you more - the noise or the music?

@boomerbillone i think of efficiency in a different way. Less efficient speakers - more filtering in the design and less music. In addition, the high power amp is another problem - more filtering,  more distortion and less music as well.  I'm sure your speakers sound great, but they are different. 

High efficiency horns need very little energy to get going so they basically make more sound with less driver effort...a good thing. I've heard some great sounding systems with lower efficiency speakers, but for me horns are magic, and I'm hooked on lower powered class A amps so it works for me.

It's rather like comparing cars, once accompanied a friend with his 5 litre V8 to a track day. He was whopped all day by a couple of 1.8 litre Lotus, on a straight track the Lotus loses on proper race track there the V8 loses. Which experience do you want?

 

No need to agonise like this.  It is all personal choice.  Don't worry about efficiency.  Get the speakers you like.

If they are low efficiency then you will listen at lower volume or buy bigger amps.

Simple as that.

Klipschorns & properly matched, flea watt tube amplification in a room designed specifically for them…vs….Apogee Scintillas with no compromise amplification in a tailor made listening environment

all source components identical

How I would love to spend a week comparing those high vs low efficiency systems!

 

@lg1 You’ll need almost a full month in order to evaluate the speakers. The human brain can be very tricky and deceiving in the short term. 

To my ears high efficiency speakers have an agility and realism not present in low efficiency speakers. Agree that lots of time needed to sort out the sound, listening tests are hard.

 

@larryi That's what I wonted to hear from you.  You're on the right track. 

Here is my take on high efficient speakers. They sound great when done right. Unfortunately, it’s not that easy to design an efficient speaker. That’s why speaker companies rather make inefficient speaker by complicating the design. Simple is better but it takes longer time to implement - that’s how I see it.

As someone above mentioned, most of these high-efficiency systems do not do really deep bass.  That is one of the tradeoffs that attend going this route.  For my taste, the very best woofers for a high efficiency system must be very agile to match the other drivers.  This typically means very light paper cones, and somewhat limited excursion (I particularly like drivers with pleated fabric or paper surrounds).  I've heard systems with twin 18" woofers per side that were still a touch limited in very deep extension, but, I really did not care much--the bass was clean, fast, and had "tone," which is more important to me.  I have no interest in a subwoofer, and several of my friends who are horn-based system experts say that subwoofers are NOT the way to go. My system has very modest twin 12" woofers per channel (pleated fabric surround, alnico magnet) in a Jensen-Onken bass reflex cabinet; it does not do deep bass.  With every system, you have to live with some limitations.