Why are high efficiency speakers preferred for low volume listening?


I am sure that this is a very basic principle, but as I peruse the speaker section I frequently see high efficiency speakers suggested for those who listen at "low levels." And is this another area that actually is "how easy the speaker is to drive (as related to its nominal impedance)" that is more important than the actual sensitivity number?

And for an example of what I am asking with that last sentence, I seem to remember when I was window shopping for speakers, seeing some Harbeth speakers at TMR with a sensitivity rated below 87 (I think they were rated at 86 or 85) but being referred to as "an easy load to drive." So would that mean that the Harbeth speakers would be good for low volume listening?

immatthewj

Perhaps a frequency bump in the 4-6 kHz range that adds “edge” to the sound and attracts attention at lower volumes.

Same can be easily accomplished with other good quality less efficient speakers like say Sonus Faber, KEF or even Ohm using DSP or equivalent parametric eq.

I’m listening to a pair of SF Concerto Domus at low volume that way using Roon DSP as I type. Might be fooled into thinking they were high efficiency horns with eyes closed.

I’m not the best one to address this but what is your budget? I just start here because the qualities you listed could lead to a $3000 system or much higher. You get what you pay for generally speaking.

In general high efficency speakers if done right can portray the source, whatever that means, in a more natural light, driven by a wide array of textures, spaciousness, power, etc.

You can get it with low efficiency but IMO it will cost more. The room might really the amplifier that determines your higher end.

The same can be said for lower efficiency. More power, more slam!

Impedance curve is simple- All drivers get similar power, or some require much more than others. That difference is the major source of the curve.

You really have get out and listen for yourself. Travel!

Good luck brother!

Easy to drive speakers avoid low impedance and phase shifts at all frequencies and require an amp work less hard in general be it at low or higher volumes. So that is advantageous. They will also tend to sound more similar with various amps.

 

Whereas high efficiency speakers simply produce higher spl overall per watt. The advantage there is mainly going louder with a less beefy amp. Beyond that any thing else is possible including a frequency response that sounds better at low volumes…or not  

 

@immatthewj Wrote:

 

Why are high efficiency speakers preferred for low volume listening?

I think it's because of milliwatts that a lot of amps produce higher distortion when operating at the milliwatt level. From Quicksilver website:  ''The Horn Mono Amplifier is designed specifically for use with very efficient loudspeakers.  It has extremely low noise and distortion as well as having 18db less gain than Quicksilver’s standard amplifiers.  This avoids the noise and gain problems that normally appear when using horn speakers.  The amplifier is designed to sound good at the extremely low levels (milliwatts) that horn loudspeakers require.  Many amplifiers actually have higher distortions at these low levels.'' See old post below:

ditusa's avatar

ditusa

1,791 posts

 

@celestial__sound 
''because 90% of the time I listen at ~60dBs SPL.''

At 60dB SPL your speakers are not getting 1 watt or 2 watts or 10 watts, in fact they are not even getting 1/2 watt. At 60dB SPL your speakers are getting milliwatts from the amp. In my experience driving low efficiency speakers with milliwatts they will sound anemic at low volume; high efficiency speakers can play well with milliwatts and not sound anemic at low volume. Also amplifiers, tube amplifiers for sure, produce more distortion in lower impedances then higher impedances. That's why I said higher efficiency and higher impedance speakers make more sense then a more powerful amp.
Hope that helps...

Mike

I am curious about this myself. I have KEF Reference One’s, which are not efficient, and years ago I had Klipsch Heresy’s, which are very efficient. Is it that high efficiency speakers are more “lively”, or was that just the horns on the Klipsch doing that? If I were to upgrade my speakers, I would probably look for something a bit more lively. 

You cannot generalize, but consider that highly efficient speakers are likely to involve horns,

the throat/directivity of horns give dispersion control cones do not.

i.e. smooth ’received’ frequency response curve at the listening position (not just 1 meter away), the different relationship of direct primary and reflected sound waves

the perception of any frequency, and clarity of instantaneous peaks is/are enhanced when less reflected sound waves are involved.

dispersion, not volume

I doubt that high efficiency speakers and good low level detail are absolutes. It’s likely more important that things like the amp being a good match to drive the speaker impedance, the system has good resolution, and that phase coherency and overall clarity of the speakers are excellent, along with a suitable room acoustics, etc...all are still significant factors regardless of the speaker efficiency.

Audio is complex, and it’s rarely as simple as isolating one parameter and calling it good. There are always good and bad examples and pros and cons with every principle you can name, and every choice you can make.

I would never buy a speaker with a sensitivity level below 92db.  Please pardon my lack of knowledge and inexperience as a technician, but lower sensitivity speakers, at least in my  experience requires the amp to bring them to life. Oftentimes I have found this to sound lifeless , requiring me to jack up the amp to breathe some energy to the presentation.

I’m not the best one to address this but what is your budget? I just start here because the qualities you listed could lead to a $3000 system or much higher. You get what you pay for generally speaking.

Actually, @bjesien  , I am currently about halfway into the audition period that MD allows (on a pair of Revels that have a sensitivity rating of 86).  I decided to get off the fence and quit window shopping because the price was right (3k which was 1400 off msrp as they were b stock).  Besides the price being right, I finally made the move because the reviews suggested that even though the sensitivity is listed as 86, they "are eay to drive" (I don't seem to be having a problem in 50 wpc triode mode, and I have yet to experiment with the 100 wpc ultralinear mode) and that they are not finicky as far as placement.But I continue to read posts in the speaker forum, and often some one asks about speaker suggestions for low level listening, and often someone or more than one suggests a high efficiency speaker.  I am sure that there is a reason for this.  However, I understood that speakers that were rated at a high sensitivity were easy to drive with low wpc amps and would play loud with those amps, so I was thinking that if one was low level listening with an adequate amp, the sensitivity wouldn't be that critical.

At the time I decided upon these speakers, there were also a couple of Klipsch speakers rated at 99 for about the same price.  Since I am listening in a small room, I am not cranking it way up, and now I am wondering if I would be happier going that way.  As I typed previously, I still have almost 30 days to change my mind.  

And that was what generated that question, @bjesien  .


I am curious about this myself. I have KEF Reference One’s, which are not efficient, and years ago I had Klipsch Heresy’s, which are very efficient. Is it that high efficiency speakers are more “lively”, or was that just the horns on the Klipsch doing that? If I were to upgrade my speakers, I would probably look for something a bit more lively. 

@zlone  , so is the bottom line that you liked the Klipschs better than the KEFs, particularly at low levels?

In my experience driving low efficiency speakers with milliwatts they will sound anemic at low volume; high efficiency speakers can play well with milliwatts and not sound anemic at low volume. Also amplifiers, tube amplifiers for sure, produce more distortion in lower impedances then higher impedances.

Thank you, @ditusa  ,  I can get my head around that.  But I am assuming it is how easy the speaker actually is to drive (and this would be due to its nominal impedance?) versus the number/sensitivity the speaker is rated at?

I doubt that high efficiency speakers and good low level detail are absolutes. It’s likely more important that things like the amp being a good match to drive the speaker impedance, the system has good resolution, and that phase coherency and overall clarity of the speakers are excellent, along with a suitable room acoustics, etc...all are still significant factors regardless of the speaker efficiency.

Audio is complex, and it’s rarely as simple as isolating one parameter and calling it good. There are always good and bad examples and pros and cons with every principle you can name, and every choice you can make.

Thanks for the feed back to my question, @knotscott  .

I would never buy a speaker with a sensitivity level below 92db.  Please pardon my lack of knowledge and inexperience as a technician, but lower sensitivity speakers, at least in my  experience requires the amp to bring them to life. Oftentimes I have found this to sound lifeless , requiring me to jack up the amp to breathe some energy to the presentation.

Thank you also, @judsauce  , for your feedback.

 

 

 

Easy to drive speakers avoid low impedance and phase shifts at all frequencies and require an amp work less hard in general be it at low or higher volumes. So that is advantageous. They will also tend to sound more similar with various amps.

 

Whereas high efficiency speakers simply produce higher spl overall per watt. The advantage there is mainly going louder with a less beefy amp.

@mapman  , so are you saying it is the way that the speaker handles low impedance versus it's sensitivity rating?  Although I would think that at low levels the impedance of a speaker would remain relatively stable and not dip?  

So is the bottom line that you liked the Klipschs better than the KEFs, particularly at low levels?

No, definitely not. For the time they were great, but I love the KEF’s, even for low volume. I just wonder if another speaker might be a little more lively at lower volumes. 

@elliottbnewcombjr  , so are you basically saying that the bottom line is that horn (tweeters?)  sound better when played at low levels than traditional cone (tweeters/) do?  Sorry if it is obvious that this is what you said, but I am not good with this stuff, and I often have trouble wrapping my head around it.

consider that highly efficient speakers are likely to involve horns,

the throat/directivity of horns give dispersion control cones do not.

i.e. smooth ’received’ frequency response curve at the listening position (not just 1 meter away), the different relationship of direct primary and reflected sound waves

the perception of any frequency, and clarity of instantaneous peaks is/are enhanced when less reflected sound waves are involved.

dispersion, not volume

 

No, definitely not. For the time they were great, but I love the KEF’s, even for low volume. I just wonder if another speaker might be a little more lively at lower volumes. 

Thank you for clarifying that, @zlone  .  (And a quick google showed that your KEFs are rated at 85.)

I just sold some Cornwall iv speakers. They were great just moved on. I will say that yes they were great at low volume as if you weren’t missing anything. Dynamics and punch and everything else intact. Problem is I don’t listen that way very often and I found something else that suits me better but at low volumes the Cornwalls were more betta. 

My not so efficient speakers, Magnepan LRS+, sound great at low volume. I find that low volume greatness requires a very quiet chain. I use a Benchmark HPA4 preamp and Sanders Magtech amp.

The LRS+ is actually hard to drive but imy setup sounds great at low volume. I have been listening at low volume late at night lately since I have the house to myself. Normally, the headphones come out at 9PM, but I am too lazy to put that system back together so the LRS+ has been given extended listening late at night.

Post removed 

I frequently say that if you have to turn your system up  to sound good, then your system sucks.  

I'm not going to say all systems with high power ss amps and 87dB speakers suck.  That would offend lots of people with very expensive systems.  But isn't it a nice coincidence that the dealer has to sell you a very expensive amp to drive your very expensive 87dB speakers.

So instead I'll say that I think the easiest way to get an awesome system is a well designed SET tube amp and some nice 98dB speakers.  No I don't care for horns.  

But once you have a great sounding system, it will sound great at 70dB and you can listen for hours on end without fatigue.  I know this sounds like a fairy tale to many.

Jerry

PS Sitting here listening this morning since 0330 and I just checked the volume with my cell phone (not calibrated) and it's showing an average of 63dB.

@immatthewj Wrote:

But I am assuming it is how easy the speaker actually is to drive (and this would be due to its nominal impedance?) versus the number/sensitivity the speaker is rated at?

Yes, nominal impedance and minimum impedance. In my opinion all three specifications are important, efficiency, impedance and sensitivity. My speakers are 96 dB SPL @ 1 watt @ 2 meters @ 8Ohms, efficiency is 2.7% and minimum impedance is 6Ohms. And the speakers excel at low level listening at 60-65 dB, and at that level the speakers are operating with milliwatts. 😎

Mike

Not sure that one detail matters too much but dynamics are super important and people underestimate how much power it takes to go instantly from 60db to 70db with a drum hit. The speaker/amp combo needs to be able to triple its power in a fraction of a second. At high volume many speakers compress those peaks. You need very large speakers or controlled dispersion (horns etc) to get there. i am firmly in the horn camp these days. The negatives of horns are reduced sound stage depth (it is more or all in front of the speakers) and in some rooms lack of sound stage width too. The benefit is better transients which to me sound more real.

At the risk of over-simplifying (and I'm not saying this is the only factor):

A significant contributor to high efficiency is a high motor-strength-to-moving-mass ratio, and it just so happens that a high motor-strength-to-moving-mass ratio is also a contributor to good articulation at low SPLs, making it easier to hear the details without needing to crank the volume up. 

High efficiency in and of itself is not a requirement for good articulation at low SPLs, as electrostats (with their incredibly lightweight diaphragms) tend to excel at delivering the details at low levels despite their typically modest efficiency. 

Duke

High efficiency plus some type of loudness contour is the ticket if you want to listen @ really low SPL's.

I've used the loudness contour in a few Quad SS preamps (33/34) and in a few Yamaha SS integrated amps with JBL S99's and Altec VOTTS.

At slightly higher SPL's, but still in the mid 70's, an odd  TDS Passive Audiophile "mystery box" did the trick though aside from being "passive" it added noticeable gain (1-3 dB).

 

DeKay

@audiokinesis wrote:

A significant contributor to high efficiency is a high motor-strength-to-moving-mass ratio, and it just so happens that a high motor-strength-to-moving-mass ratio is also a contributor to good articulation at low SPLs, making it easier to hear the details without needing to crank the volume up. 

High efficiency in and of itself is not a requirement for good articulation at low SPLs, as electrostats (with their incredibly lightweight diaphragms) tend to excel at delivering the details at low levels despite their typically modest efficiency. 

I'm thinking whether a large air radiation area may also be a co-contributor here, having to move less for a given SPL which also leads to less inertia built-up/less smear, and thereby sharper or cleaner transient "edges"? Maybe what you're saying is essentially the same. 

On Sale!

I love a bargain, part of the enjoyment of anything I have is remembering the ’find’, trade, great deal each and every time I see/use a thing, but

A bargain price is not the way to make a selection in an audio chain, especially speakers. Determine a short list of what is best/desired for that space, then search for the patience to wait for a bargain for something on that short list.

Speakers: if you want to hear them each time you awake or arrive home, walk thru the room, done,

Blue Nile

but your inquiry indicates that ain’t happening with those KEFs.

(substitute ______ for KEF above, any speaker, especially rear ported ones)

Cones (no advantageous directivity) and Two rear ports, technically different, are producing a beloved but ungodly mix of primary, secondary, .... sound reflections. Parts are working too hard to attempt what they really cannot do.

Designed/tested/measured in a Phone Booth/Foam Room, shipped like a blind sailor hither and thither, where am I??????????

Small space:

fit/appearance/performance must come together, it really has nothing to do with volume. If, like me, you want tubes in a small space, the short list needs to be efficient to minimize heat.

In any case, I advocate NEVER listening to inefficient speakers, never, make a short list of efficient speakers for each space you are dealing with, avoid the devil.

LOW Volume:

As a matter of fact, the Fletcher Munson Loudness Compensation equalization should have been the 1st thing mentioned. Our ears are LESS sensitive to low bass and highs AT LOW VOLUMEs, thus ANY speaker, any design, any efficiency will not sound best at low volume in ANY space, unless carefully placed, aimed, adjusted.

Frequencies relative to Volume, fletcher Munson

Stupidly named ’Loudness’, perhaps ’Low Volume’ would have been smarter, and poorly implemented/understood still..

Controlled Directivity (horns have an advantage over cones).

I was writing about the clarity, smooth frequency response when there is a higher percentage of direct primary sound waves (actually received, at the listening position), as opposed to too many secondary .... reflected sound waves. arriving too soon.

Horn Tweeters important because high frequencies are the narrowest,

but horn mid-range is far more important.

Toe-In Alternates, 1 or 2 listeners

....................................

Other than that, I’ve been mistaken for someone who has an opinion on the matter.

 

 

@james633 Wrote:

The negatives of horns are reduced sound stage depth (it is more or all in front of the speakers)

Not all horns are created equal, these horns have great depth of image, when the recording calls for it see here. It's been my experience in audio, that high efficiency and high power handling are two attributes that make for wide dynamic range in speakers.

Mike

@audiokinesis  , thank you for oversimplifying.  That helps.  

@james633  , thank you for the feedback on this.  I think I am getting the picture.  High efficiency doesn't take as much power to move and at lower levels not as much power is being provided to the speaker as at higher levels.  

@elliottbnewcombjr  , I am actually not the one with the KEFs, that was @zlone  .  I am trying out a pair of Revel M126Be's.  I like them so far, but after reading posts here in the speaker forum, I am questioning myself as to whether a higher sensitivity speaker would have been a better coice in the small room I listen in.  My amp does not seem (to me) to be straining in 50 wpc.  I know your opinion of triode versus ultralinear, and today I put another 5.5+ hours on them, and for the last couple of hours I went to 100 wpc ultralinear and I felt that female vocals took on a bit of an edge in that mode.  I guess the final proof (or close to final) will come in about 20 more listening hours when I follow @soix  's advice and hook up my old speakers and see how I feel about the difference.  As always, I appreciate your feedback.  It is always welcome. 

I've never observed any correlation between high efficiency speaker and improved performance at low levels. Rather, (again, IME) the most important characteristics to enjoyable listening at low volumes are resolution of low level detail and microdynamic shading (as opposed to macrodynamics).  These can be found, to varying degrees, in both higher and lower efficiency speakers.

With that said, at the extreme, I have noted as a characteristic that very low efficiency speakers (e.g., <84 db/W/m) tend not to be very good at preserving microdynamics.

I came across this article a few years ago and it’s worth reading/noting.  Adds some “grist for the mill” for the conversation here I think.

WHY THE SET & HIGH EFFICIENCY SPEAKER APPROACH WORKS

DEC 2020
by Steve Deckert

 

Matching inefficient speakers to capable amps can overcome the loss of low volume dynamics that happens to us with large speakers. 

Something I can speak first hand to. 

My wife is a nurse and works nights, sleeps during the day.  Our bedroom is directly above the listening room.  Fully half the time I listen to my system when she is sleeping.  My Maggies (84 db sensitivity) at low volume give me so much detail and even dynamics that it full out surprises me almost every time!  I've had guests comment on exactly the same surprise that such low level listening can produce such detail.  I also have two REL subs hooked up and the bass at low volumes is ever present.  I fully believe it is a mix of electronics and speakers and I cannot agree with the statement that high efficiency correlates to quality listening at low volumes - Not on my system anyway.

OP,

thanks for catching my memory lapse and I really am referring to port/no port, omni-directional, controlled directivity.

here a KEF, there a Revel, any where you go ...

you wrote

"so I was thinking that if one was low level listening with an adequate amp, the sensitivity wouldn’t be that critical."

I absolutely agree, in theory, assuming no mis-match of equipment/space/placement/frequency distribution ’received’ at listening position. which is: an impossible assumption/comparison.

my friend’s little KEF Reference 1’s needed some serious juice (spl 81, sealed, no ports), made a great 1st impression. His mono block beasts burnt out after a while. Bass only down to 90 hz admitted to in those days. He built a table with an enormous down firing sub to that system after a while, I’m afraid to remember 30".

KEF Reference 1, sealed, no port, spl 81db

Add a port (other KEF, Revel, .....), sensitivity goes up a bit, all the way up to 86db hah, and bass performance goes lower a bit, however, now you have a much higher amount of indirect secondary ..... sound waves.

you also quoted:

"they are not finicky as far as placement." (about the ported Revels).

I think, when a port is involved, any/all locations already involve so much reflected sound ....., whereas, no port, front emanation, the placement(s) make a more discernable/measurable difference, so .... ported is less finicky isn’t necessarily a good thing.

..........................................

this becomes academic, a choice has to be made for a small room, many small ported speakers sound very enjoyable with or without a sub.

 

 

 

 

low volume is a separate issue

and there is no getting around the established facts that at the least low bass needs to be boosted at low volumes, ideally 'progressively boosted' as volume lowers.

Where's Wally? Where's Ray?

Play some Jazz, Ray Brown with others or his trio. Lower the volume, ... lower some more, where's Ray? For me, it is maintaining the Bass Player in Jazz that maintains involvement when listening at low volume. Otherwise it quickly becomes un-involving background music.

No matter how much we want to avoid the truth regarding 'loudness compensation'' (because so much modern equipment lacks solutions for it), success depends on both understanding and being equipped to solve the requirement.

you youngsters: get thee vintage features:

"Amplifiers often feature a "loudness" button, known technically as loudness compensation, that boosts low and high-frequency components of the sound. These are intended to offset the apparent loudness fall-off at those frequencies, especially at lower volume levels. Boosting these frequencies produces a flatter equal-loudness contour that appears to be louder even at low volume, preventing the perceived sound from being dominated by the mid-frequencies where the ear is most sensitive."

"Loudness compensation boosts low and high frequencies when listening at low levels so that the ear perceives an overall flatter (substitute accurate for flatter here) sound pressure level. This helps quiet sounds be easier to hear, and prevents loud sounds from overwhelming the listener."