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

My friend is a DIY speakers builder. He also fixes drivers.

He had and measured dozens different 15' driver JBL, Tannoy, Altec,... He says the maximal sensitivity of 15' driver in vented box (of any size) at 100Hz is 94-95dB. Some 15' drivers like Altec have higher sensitivity around 200-300Hz but it drops to 95dB at 100Hz. 10'-12' have even smaller sensitivity at 100Hz.

 

Because the speaker manufacturer displays frequency response graphs for each loudspeaker they sell.

i’ve also run sweeps myself, seeing the same response.

My experience this is not a particularly unique frequency response using high sensitivity loudspeakers. More common than not.

@johnnycamp5   100% , just want to figure out , how  you know( My mains (104db) start to drop like a stone at around 80Hz. )

After reading (and re-reading) all of "bache" posts, I think I understand what he's saying-   "High sensitivity loudspeakers roll off rather high in the bass department".

Forgive me but Isn't this captain obvious? Are there many folks that listen to high sensitivity speakers without a sub or two?

My mains (104db) start to drop like a stone at around 80Hz. 

Sure theres still some output at 40Hz. but its very light in the a#$. I use dual subs to fill in those bottom two octaves.It also helps smooth room modes..

So after going through the trouble to blend them into the system, I would never go back to 

 

 

It’s about the implementation and physics. Sure you can have, say, 97dB sensitivity and honest 20-25Hz extension - that’s from a tapped horn at 20cf. volume with a high-ish fs (35Hz) pro 15," proper motor strength, not too low mms (i.e.: +150 grams) and overall complementary parameters for its specific use. The horn does the heavy lifting and fills out the extension and amplitude gap the driver normally couldn’t handle. Way smart.

I would be cautious pairing high eff. main speakers with low eff. subs - it doesn’t really gel. You want high eff. and extension to boot you go the distance with size to follow and high eff. all the way; it pays off sonically and certainly is realistic - where there is a will to let size (and the required design) have it’s say.

Run it all actively with high-passed mains and treat it as one speaker system pr. channel incl. subs with carefully implemented delay settings and overall filter parameters via a capable DSP - not just with the latter patched on where the (passively configured) mains roll off naturally. Just my $0.02..

As an owner of Tannoy Berkeley's I would tend to prefer high efficiency speakers.

In fact all of my previous speakers have tended to have been of reasonable high efficiency (>89dB). All except the Quad 57s which I could not get the best out of, but that may have been an impedance issue.

 

However, there must be a trade off between efficiency and accuracy, or else why would anyone bother with crossovers?

Then there's also the question of damping.

Heavier cone materials tend to be better damped than lighter ones, but it's arguable whether they are more accurate, especially if they are dynamically challenged in comparison.

Newer materials like carbon fibre seem to promise both better efficiency and damping but not everyone is convinced. Then there's stuff like graphene which may yet be better than any we have seen so far, but there's little sign of true graphene coned drivers yet.

 

As ever, it's a question of trade-offs and preferences.

Just which kind of accuracy would sir prefer?

@bache

Cool down!? You’re the one using derogative names and I’m suppose to cool down. What is wrong with you? Stop deflecting and projecting your arrogant attitude to others and stop waisting my time, please. No mater what I do or say, you’d never believe it, but I bet you’d not have any problem believing in QAnon conspiracies.  I know your type of personality  very well. 

Hi @mijostyn ,

My SET amp plays down to 7Hz -3dB. And plays bass much more in real, natural way compared to any other amplifier I had before.

Experience DIYer can built SET amplifier that sounds better than most of amplifiers available on the market. It wouldn't be cheap but such amplifier can't be bought by any money and it will be tweaked and tuned to special speakers and person.
It's way more effective than cable lifters (despite cable lifter works).

Regards,

Alex.

Hi @bache ,

The question: what is high sensitivity? Yes I agree. For real high sensitivity let say 98dB and up it is an issue. For a 15" driver with 94dB sensitivity bass can be good down to 35-40Hz. 

Regards,

Alex.

 

@tannoy56  please cool down  , t think you big fan tannoy,  This is a very good Co, no question ,   They make only 93db sensitivity passive LS  and make now good line with build in Class D amp   .   And  also  , dont biieved for 100 % , what they say, check  ability to produce below 30Hz, and let us know , if you listen something 

after that -- i say Thank  you

 

@bache You don’t give up easily, do you?

https://www.hilberink.nl/codehans/tannoy4.htm

Would be nice if you respond back by saying - Thank you.  

 

@tannoy56  Below 30Hz ??   .  If  You dont want check by Sound Generator , there are a lot test Cd    to check it . Please  check and let us know.

@alexberger   bass below 30-40 Hz is not issue. High sensitive drivers  got low moving mass and resonance up to 60-70Hz , so is basically got low performanse in bass . I build my Ls assosiated with my name with build in active bass, also is very important to mach the phase with middle bass . Theoretically is it possible improve the bass , but  cabinet size must be huge

Hi @bache ,

Yes, sensitive speakers do not play bass below 30-40Hz. But this is a compromise with the texture in the middle bass and lower mids, which is absent in dull speakers with low sensitivity.

Regards,

Alex.

@tannoy56 I only ask sincerely and not to disparage “bache”…

but how can you even make sense of what he said?

 

@bache With the right speaker enclosure, Tannoy dual concentric 15" speakers and many other efficient speakers extend down to below 30 hz. Not to mention that 90 percent of the music is in the midrange frequency. Who is stupid now? I didn’t want to do this to you but you made me do it. Ignorance can be a blessing. No wonder why Tannoy was the most widely used speaker in studios around the world, including Abbey Road. I guess, they were stupid too.

@phusis

Sounds to me like you’re hitting the right notes, so to speak, from your descriptions.

I have had this SET set up since 2009 and can honestly say that I appreciate it more than ever.😊

+1 @ozzy62 

@charles1dad wrote:

Yes, this accurately describes my copacetic listening scenario. 8 watt SET mono blocks driving 94 db sensitivity /14-ohm impedance speakers. My typical listening levels sitting 10 feet away are  C-weighted 65-75 SPL

Can dip to the mid 50s (softer passages) most ofren peaks (mid 80s).. I can listen at louder levels comfortably, but no need to.

About the same levels for a large portion of my music enjoyment (right now averaging just over 65dB's C-weighted with my evening listen of Keith Jarrett's 'The Carnegie Hall Concert'), except with a range of well-recorded and not too dynamically compressed classical recordings, some electronic genres and watching movies, where higher peaks (via a wider dynamic range) do occur.

At these very satisfying listening levels the SET is far below 1 watt of power (Small fractions of one watt) and doing so at a very low level of distortion (As you note). The sound is very tactile, resolved, pure, natural and quite emotionally engaging. Key take away is the amp and speaker must form a compatible match.

Charles

With 8 watts of SET power given the speaker context, listening levels and distance this combo should be perfectly suitable. Sounds to me like you're hitting the right notes, so to speak, from your descriptions. 

High Sensitivity Speakers without support sub or build in active woofers got low performance to produce low bass but some listeners dont care about low bass' They looking on techical characteritic and stupidly believed , what it say 

mijostyn

6,375 posts

08-15-2022 at 09:50pm 

@charles1dad , dogmatic maybe, presumptuous, not at all. What you are listening to is a study in colored inaccuracy. You can like it all you want but calling it accurate is a big stretch. 

Maybe not dogmatic. But you are like a dog shaking a bone. You just don't want to let it go. And @charles1dad is probably the most cordial guy on this site. He makes disagreeing seem like something not so bad after all.

 

 

My Line Manetic Field Coils Speakers are 105db Sensitivity, Their are dynamic and yet smooth, musically invovling, My Classic Audio Loudspeakers are 100db Field Coils.

 

Both of these speakers to my ears give one dynamics as closer to live performance and as a result are more emotionally invovling and exciting to listen too. it does not bore you to death.

 

Been their and done that with low efficent speakers and high powered Tube or Solid State amps never again.

To write off all SET in this manner is total nonsense. I've had ss class A and AB, push pull tubes with various power tubes, and SET with various power tubes. Low, medium and hgih sensitivity speakers with the above. So, it seems my evolution towards SET is in fact, a descent into inaccuracy according to mijostyn. I guess having living, breathing performers in room is in fact inaccuracy.

@charles1dad , dogmatic maybe, presumptuous, not at all. What you are listening to is a study in colored inaccuracy. You can like it all you want but calling it accurate is a big stretch. 

Not my set-up, unfortunately, Kharma/Lamm SET deliver super performance.

Kharma is medium efficient, I think.

@mijostyn 

You are dogmatic and presumptuous in your dialogue.  Let's just agree that you and I have very different experiences and perspective and leave it there. We both have found over the course of time what hast proven to satisfy our respective audio/music listening goals. We are both quite happy with our audio systems. Some on this thread can relate to my perspective and others here relate to yours. That's fine with me.

Charles

@charles1dad , I said "FEEL" like you are in a small Jazz club. I hate to be a stick in the mud but forgetting about SET, amps higher powered amplifiers have trouble getting low bass right. If you thick a SET amp can get even close you and I live in different universes. SET amps are for hobbyists, the guys who like short wave radios. To each his own for sure but I am talking about a specific level of performance one in a thousand systems might reach and not one of them will have a SET amp. 

 

@phusis

No, SET’s for when they make sense; with high to very high sensitivity speakers to take advantage of the less than 1 watt where the distortion levels found in these amps are extremely low here, just like with the speakers they’re feeding that efficiently turns electrical power into acoustic energy.

Yes, this accurately describes my copacetic listening scenario. 8 watt SET mono blocks driving 94 db sensitivity /14-ohm impedance speakers. My typical listening levels sitting 10 feet away are  C-weighted 65-75 SPL

Can dip to the mid 50s (softer passages) most ofren peaks (mid 80s).. I can listen at louder levels comfortably, but no need to.

At these very satisfying listening levels the SET is far below 1 watt of power (Small fractions of one watt) and doing so at a very low level of distortion (As you note). The sound is very tactile, resolved, pure, natural and quite emotionally engaging. Key take away is the amp and speaker must form a compatible match.

Charles

 

 

 

@mijostyn wrote:

we have to disagree about something. Try driving an ESL with a SET amp. Do I smell something burning?

And it ain’t the toast. No, SET’s for when they make sense; with high to very high sensitivity speakers to take advantage of the less than 1 watt where the distortion levels found in these amps are extremely low here, just like with the speakers they’re feeding that efficiently turns electrical power into acoustic energy. Think about the power that’s wasted as heat with low sensitivity, passively driven dynamic speakers, not to mention the poor cone/diaphragm to air coupling - waste upon waste, really. It’s all about the most efficient transfer, and lastly from the speakers to the ears and how to "capture" the acoustic ditto here, which is also a reason why I’ve never dug heavy absorption - it potentially makes matters worse energy-wise:

 

The critical distance for medium size room at 1KHz less then 2m. Actually 2m is the worst case. 

So, the pik volume can generate the system with 300B amplifier is -

spikers sensitivity + 9db (8w) - 3db (2m critical distance) + 3db (two speakers).

For example for 95dB speakers we get at least 104dB.

You can get "absolutely sound" with SET.

For example, 300B SET and ~95dB sensitivity 15" JBL or Tannoy in medium size room. If 300B SET build properly you can get enough dynamic headroom for any kind of music. From small jazz to symphonic music and rock.

The problem is - 99% of SET amplifiers designed and built for Lowther like speakers.

@jfuquay 

After decades of close listening, what if you learn you prefer a low-sensitivity speaker, like Magnepan in my case? Then I say you find the electronics to drive it and just enjoy it

Pure logic and experience clearly confirms this. Stubborn dogma isn’t persuasive or necessary. Choose what works and sounds best to you and pursue to the best of your ability.

Your approach is the opposite of mine. Does not matter, we both have found what individually suits best.👍

Charles

 

Interesting question because it puts two legitimate concepts in opposition. One is the view that the less you mess with the signal, the better the sound. Therefore, simple, well-designed amps are “best.” And those are going to tend to be low power. You could argue that means high-sensitivity speakers must follow, so you’ve got the perfect pairing. Except speaker sound is totally subjective (“it’s all in your head!”), and the variations in speakers are vast compared to electronics. After decades of close listening, what if you learn you prefer a low-sensitivity speaker, like Magnepan in my case? Then I say you find the electronics to drive it and just enjoy it. 

I am a fan of the low power / high efficiency pairing.    I also feel that most higher efficiency speakers sound like live music and can be more dynamic.  I think they often sound better at lower volumes.  Just went from a pair of 40 watt Push Pull amps to a 300b and it's plenty of power for my space and listening habits.    

If you can close your eyes and feel like you are at a small jazz club you are on the right path. Cable elevators excluded

This is precisely what led me to SET. Very frequent attendance at local jazz venues for the past 30 or so years.We all find our own paths. I respect everyone’s road to Rome.

Best wishes 

Charles

@phusis we have to disagree about something. Try driving an ESL with a SET amp. Do I smell something burning?

You can get good sound with passive systems and I have heard one passive system that got very close to the absolute sound but, you can take any passive system and make it better within the limits of the equipment and room. 

@larryi , you can get reasonable sound out of a SET amp with efficient speakers but you will never get to the absolute sound. It is a path with a dead end. 

What is the Absolute Sound? Go to Boston Symphony hall and sit 10th row dead center. Got to a small Jazz club and sit up front. Close your eyes and listen to each instrument. That is the Absolute Sound. This can be done in a home environment and there are several paths to this result but there are certain approaches that simply will not get you there. They may have a pleasing result but not a chance at Absolute Sound. 

If you can close your eyes and feel like you are at a small jazz club you are on the right path. Cable elevators excluded

.  

@mijostyn wrote:

SET amplifiers are about as silly as cable elevators.

Don’t agree with this however - that is, regarding the SET's.

@mijostyn wrote:

horns are a very alluring proposition. They are efficient and there is no question they can play louder than any other type of system with low levels of distortion. You can also control the radiation pattern to limit room interaction, another big plus.

Indeed. More though than the ability to play loud with low levels of distortion is their sound at more average SPL’s with even lower distortion and the sense of aliveness in music intact (which may otherwise require higher SPL’s), the ease of reproduction this offers and the prodigious dynamic headroom that allows uninhibited transient peaks and full dynamic swings. The ability to play loud well isn’t really about stretching this envelope to the max., not to me at least, but (to stay in the car analogy) to feel that the engine has power in reserve for any occasion readily at your disposal (i.e.: sense of effortlessness), as well as - and not least - a sensation of inherent power lurking beneath. The sense of power in sound reproduction (all tied into the above) is vastly underrated, if you ask me.

Unfortunately they fall short for a number of reasons. There is no such thing as a full range horn. You are forced into having a crossover somewhere in the midrange or upper bass. Many horn systems run a dynamic woofer well into the midrange, so much for low distortion. It would be a complicated mess trying to make a line source horn system.

True, the wretched cross-over(s) and where to place them. ESL’s no doubt have a big advantage here. Trying to emulate a line source is not necessarily the goal though; within the limitations given here my effort has been to reduce the number of cross-over points down to a single one in the main speakers, and focus on maintaining dispersion characteristics at this chosen point from the dual woofers up through the horn. Being that the sound emanates from this +6 ft. radiation surface is not wholly unlike that of a large panel speaker - in its overall presentation at least. With steep filters (6th order) via a DSP and a HP on the woofers at 83Hz and a LP at just over 600Hz, distortion subjectively is very low. They move zilch even at bonkers SPL’s.

Line Source systems are the only way to get into the first 10 rows. ESLs can cover 100 to 18 kHz no problem, no crossover. They maintain the lowest distortion levels throughout that range. Crossing to a sub at 100 Hz is much less of a problem especially if done with steep digital filters.

Absolutely - ESL’s are widebanders in ways dynamic loudspeakers can’t equal. You can however effectively emulate a single source merging several drivers in a single horn as Danley’s Synergy Horns, and as far as distortion levels go - depending on where we look for them - they can be vanishing low via horn speakers as well. I have an 111dB sensitivity horn/comp. driver combo looking directly into a class-A amp with no passive filter components in between, using only factions of a watt with normal playback. That’s way low distortion levels.

The only disadvantage ESLs have relative to horns is that they are much less efficient. The fact that they won’t play as loud is not a problem because they will do 105 dB and anything louder than 100 dB is certainly damaging your hearing.

The occasional peak levels of +100dB’s found in live acoustic performances or non-compressed recording playback isn’t a problem, it’s blasting away at continuous loud levels with compressed material that will take its toll on the ears. Oh and of course instantaneous mega loud blasts like explosions or other can also be severely damaging on ones hearing.

And to reiterate: to do 105dB's peak cleanly at the listening position you need way more SPL capability than that - at least if you want to know what effortless playback really is. 

I am a huge proponent of actively driving loudspeakers. This does not mean that all the wizardry has to be within the loudspeaker. You can actively drive any loudspeaker with outboard components. I have been doing it for 20 or so years.

Fully agree, it’s what I do myself with outboard components (though not for 20 years - kudos).

There is no other way to get the absolute most out of any system and this is not IMHO. I have seen, heard and measured enough to know this is a fact. If there are any downsides to this they are far outweighed by the benefits. Trying to maintain a totally analog system is like owning a vintage Corvette. If you are a track junkie you will go a lot faster in a C8. I’m not into owning antiques. I like driving fast.

Won’t argue with that either, but I certainly respect and acknowledge that very good sound can be had in passively filtrated speakers.

SET amps are silly if you use them in the wrong system, or, if you get cheaply built crap that stint on the quality of the output transformer and other critical components (because they are simple in design, some mistakenly think they can spend less on SET amps and still get reasonable quality).  That said, I am not particularly wedded to any type of tube amp design.  My all-time favorite amp is an OTL design, my next favorite is a push pull triode amp, and the favorite among the amps I own is a push pull pentode amp; my next favorite is a parallel SET.

SET amplifiers are about as silly as cable elevators.

Silly statement. 
Fortunately the easy solution is to avoid them if that’s how you feel. We can respectfully disagree with one another and just leave it at that.

Charles

SET amplifiers are about as silly as cable elevators.

@phusis , horns are a very alluring proposition. They are efficient and there is no question they can play louder than any other type of system with low levels of distortion. You can also control the radiation pattern to limit room interaction, another big plus. Unfortunately they fall short for a number of reasons. There is no such thing as a full range horn. You are forced into having a crossover somewhere in the midrange or upper bass. Many horn systems run a dynamic woofer well into the midrange, so much for low distortion. It would be a complicated mess trying to make a line source horn system.

Line Source systems are the only way to get into the first 10 rows. ESLs can cover 100 to 18 kHz no problem, no crossover. They maintain the lowest distortion levels throughout that range. Crossing to a sub at 100 Hz is much less of a problem especially if done with steep digital filters. The only disadvantage ESLs have relative to horns is that they are much less efficient. The fact that they won't play as loud is not a problem because they will do 105 dB and anything louder than 100 dB is certainly damaging your hearing. 

I am a huge proponent of actively driving loudspeakers. This does not mean that all the wizardry has to be within the loudspeaker. You can actively drive any loudspeaker with outboard components. I have been doing it for 20 or so years. There is no other way to get the absolute most out of any system and this is not IMHO. I have seen, heard and measured enough to know this is a fact. If there are any downsides to this they are far outweighed by the benefits. Trying to maintain a totally analog system is like owning a vintage Corvette. If you are a track junkie you will go a lot faster in a C8. I'm not into owning antiques. I like driving fast.

The main design issue is weak power supply and weak driver tubes. The only SET amplifier I know (probably there are another) that don’t have these issues is Coincident Frankenstein

Agree completely!

All low power SET amplifiers are not created equally. Some will succeed admirably where others will fail, and for the very reason you eloquently state. Robust high quality power supplies and appropriately chosen driver tubes are critical steps that have to be taken.

As far as I’m concerned, the contribution of a component’s power supply can not be overstated. In the best sounding/performing components this is where the money and attention is wisely committed. The Coincident Frankenstein is a good example but there are certainly others as well.

Charles

Lower efficiency speakers gives designers much more opportunity to “voice” things. At least that’s my uneducated opinion. 

Hi @sns ,

You mentioned a very important question.
Most low power DSET (45, 2a3, 300b,...) made today and before designed for very easy load and very hight sensitivity speakers file full range Lowther, Fostex, Voxativ,...
But in therm of pik volume these amplifiers can work for midsize room and ~95dB sensitivity speakers like big JBLs and Tannoys. But in the real live they don’t work properly even with more sensitive Klipsch and vintage Altec speakers.
The main design issue is weak power supply and weak driver tubes. The only SET amplifier I know (probably there are another) that don’t have these issues is Coincident Frankenstein.

I have been using a good DIY 300B DSET (6sn7 input, 6f6 driver) since 2006 with Altec 604E. This combination played nice but it had pronounced genre preferences. It was good for small jazz and classical groups, great for vocals but disaster for any kind of electronic music, rock, fusion jazz.
When I increased capacitors value and quality (oil capacitors) in the power supply and divided the right and left channels PS by resistors. It dramatically improved bass, dynamics and separation on bass heavy complicated, congested music. My solution is not optimal as my stereo amplifier uses one power transformer, rectifier and choke. Monoblock solution should be significantly better.
But the bottom line - the main issue in DSET in combination with big woofer 15" speakers is not lack of power but lack of ability to produce enough current. And the reason for this is not enough powerful power supplies. To drive 15" speakers some audiophiles go in the direction of big 845, 211 DSETs, but I’m not sure that this solution is the only one. 2a3 or 300B with a good big power supply can be another very good and more affordable one.

Regards,

Alex.

Bass gives a foundation. This is a very big disadvantage of high efficiency design. 

Not to mention that many just don't tolerate horns.

Anyway, it's amp-speakers unit in a particular room, right.

 

While it may not be optimal, I’ve heard large horn systems in some really small rooms that sounded very good.  Check out Japanese audio magazines and you will see large horns in tiny Japanese apartments.  Japanese people are very considerate and would not be inclined to bother their neighbors so they would play their systems at low volume.  It is at LOW volume that horn systems shine.

In my opinion high efficiency for larger rooms. Less efficient for smaller. It all depends on the room which affects the over all sound. Klipsch  Horns in a 12x12 would sound awful.  In a 20x20 wonderful.  Also depends what's in the room.

lowest eficiency is bad for my single ended el84