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

Big fan of high sensitivity speakers especially because they work well with low power SET amps.

I prefer high efficiency but I don't undersize my systems so I get bass into the 20-30hz range on most systems. I find higher eff designs to have a more realistic sound quality if done right. But many are too compromised in size. But sadly so are most of the loudspeakers offered today. Shipping costs and material costs all lead to smaller and smaller designs. I get 1 tear in my eye at audio shops it's all too small. 

The best performance comes from electrostatic speakers. They are generally mid efficiency speakers but are very amps sensitive and owner sensitive. Otherwise it is 6 of one 1/2 dozen of the other. The best performance I have heard come out of dynamic loudspeakers came from inefficient speakers driven by huge amplifiers. 

All good comments up to now. I'd only add electrical impedance is critical measure of truly efficient speakers.

 

As owner and modifier of Klipschorns I have had choice to continue with shallow slope crossovers or go to steep slope. Klipschorns nominal impedance with stock shallow slope crossover rated as 8 ohm, with 104db sensitivity,  it would seem to be easy to drive speaker. In reality there are drops down to 3 and 2.7 ohms with steep phase angles, requires fair amount of current. Taking this into account impacted my choice of amps, 45 and 2a3 SET were considered but eliminated due to these severe phase angles which really require amp capable of delivering some current at 4ohms. I settled on custom built 300B monoblocks which have pretty massive power supplies (each have PS equivalent to what one would normally see in stereo 300B). While I may yet try a 2a3, would have to have pretty special power supplies to cope with these phase angles.

 

So, for me a truly high efficient speaker is one that 45 or 2a3 flea watt amp can drive comfortably, this would be 100+db sensitivity with benign electrical impedance curve. Klipschorn or other 100+ sensitivity with less benign impedance curve something slightly less than truly high efficient.

I think the thing that matters in the end is what sounds best to the listener & how the speaker sounds in the room with the paired electronics. No matter what the opinion is,  the end result is a dice roll.

@mijostyn that is interesting…it’s the polar opposite of my experience 

@larryi wrote:

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

Glad you found it worthwhile.

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.

Smoothness, or lack thereof in frequency response can definitely be a factor, I agree. Great horns don’t really sound like horns (if there even is a decided consensus about what horns in general sound like, and with the implicit notion here perhaps that "horn sound" has a more or less distinct character), and the bigger they are even less so, I find. Yet, large and great horns definitely don’t sound like smaller, low efficiency direct speakers either, but are in some respects more reminiscent of very large panel speakers. Indeed I would go so far to claim that some don’t like horn sound just by virtue of it sounding different compared to low. eff. direct radiating speakers, even if the former are devoid of uneven frequency response or colorations in general.

@audiokinesis wrote:

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.

The EV Constant Directivity horns (HP9040 + DH1A) on my EV main speakers, by virtue of not narrowing the HF response on-axis, should require equalization in its upper band above some 3kHz, at least for their intended cinema use, but surprisingly we’ve only found it necessary and most important to apply some notches and a peak suppression via a Xilica DSP (active config.). This ameliorated a slightly can-ey and mechanical imprinting for a very smooth upper band reproduction. The lack of a need for an EQ gain-boost in the upper octaves I’m guessing may have to do with the limited spacings they’re now used in vs. large auditoriums, with the former providing some boundary gain. What’s your assessment here?

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.

The EV horns of mine both have a diffraction slot and sharp edges at the mouth area, and so may set the alarms ringing in many a horn-audiophiles’ head, but they actually sound very smooth after being properly implemented with mentioned DSP filter-actions above.

What’s less discussed or acknowledged even is the importance of horn size and its sonic implications. This is also a factor determined by the compression driver used here, with the very powerful DH1A being more properly loaded with the HP9040 horn compared to the smaller HP940 sibling (which I used previously). The DH1A simply seemed to "shoot through" the smaller HP940, but the sonic outcome also had to do with the horn resonance being placed higher in the upper mids on the HP940 vs. in the lower mids on the HP9040.

In any case a larger horn appears to fold-out the sound much more effectively for a more relaxed imprinting than a smaller horn, while also sounding more fully developed physically. Things being equal a smaller horn sports the more intensely "directed" sound (to many perceived as a horn-sound characteristic?), and the larger ditto has a much larger, even a huge and more relaxed sphere or bubble of sound.

I know horn geometry and diffraction eradication found in newer horns is very important sonically, but you come a long way with blunt, physical size in older more industrial (and still very well developed) designs, I find. Size is less sellable, though, and many don’t like the mere association with pro segment products.

Thanks for your great contributions, Duke.

@johnk --

Well put.

@johnnycamp5 , Then I guess you need more experience and I am not trying to be harsh. I really mean it. I went through life as an inexperience audiophile for decades. Then I got involved in the business directly and was exposed to hundreds of systems and I was responsible for designing at least 50 of them, all very high end for the time. I am also extremely inquisitive and structured. I AB equipment all the time and have learned to divorce my imagination from the process.

It is also quite possible to make the finest systems sound terrible. Very few of us have actually listened to a SOTA system and do not know how much performance is available and what it sounds like. 

@wolf_garcia 

I believe some horn speakers built today have gotten much better at imaging than horn speakers of the past, but if you're a fan of imaging, there are still a lot of horn speakers that don't image real well. I for one am a big fan of imaging and that is why I own Maggie 20.1s. Speaking of Maggies, which in my opinion should always be paired with a sub, can you imagine how little bass they would produce if they were high efficiency? Although there may be some planar speakers that are high efficiency, I can't think of any off the top of my head.

@mijostyn that is interesting…it’s the polar opposite of my experience 

@johnnycamp5 

This is the beauty of open discussion forums,  a broad expression of numerous listening experiences from a diverse group of music lovers/audiophiles. I’ve had the fortune of hearing quite a few electrostatic speaker based audio systems. Some were quite good.

however, if given a choice between that type of system compared to a high quality higher efficient speaker driven by good quality low power tubes, I’ll choose the latter every time. It is not a proclamation, my ears and taste  are not superior to another’s. It is just simply after many years and much exposure to various systems, I just know what suits me best and sounds best to me.

 

On the other hand I can easily understand why electrostatic speakers and big transistor amplifiers would have enormous appeal to another listener. This is an extremely personal endeavor without question. The vast spectrum of choice in High End audio is precisely what makes it so special.

Charles

@phusis wrote:

"The EV Constant Directivity horns (HP9040 + DH1A) on my EV main speakers, by virtue of not narrowing the HF response on-axis, should require equalization in its upper band above some 3kHz, at least for their intended cinema use, but surprisingly we’ve only found it necessary and most important to apply some notches and a peak suppression via a Xilica DSP (active config.)... What’s your assessment here?

The short answer is, I don’t know.

Perhaps the crossover filtering is providing the equalization without obviously using a dedicated EQ circuit, by cutting the lows instead of boosting the highs. Perhaps EQ is being applied somewhere without you knowing about it. Perhaps your compression drivers have signifcantly better frequency response than the published curve; I have found that to sometimes be the case, the manufacturer apparently having made unannounced improvements in the frequency response... but usually not to that extent. I don’t see an impedance curve online, perhaps there is an amplifier interaction with the impedance curve which results in a rising top end with your amp, or which resulted in a drooping top-end when the published curve was measured.

That being said, the published unequalized curve for that horn/compression driver combination looks right to me. It looks like the curves I get with large-format compression drivers on constant-directivity horns.

All of the above speculative explanations are unlikely, perhaps even highly unlikely, which brings me back around to "I don’t know".

Sorry about that!

Duke

Should what type of music you listen to be included in the opinions?  Would light, airy, lit from within sound be desired by people who listen to chamber music, classical in general and softer jazz?   Would rock, pop and harder jazz listeners prefer a different sound?  I don't know, but it seems like a possibility.

@winnardt    

Apogee duetta signature can be rebuilt to be higher sensitivity, with the newer bass foils and newer midrange/tweeters and better magnets can get them up to 96-98db.

​​

@mijostyn @charles1dad 

Absolutely!

Its why I said IME…

• Its why I said IME…

👍

@phusis wrote: 

The EV horns of mine both have a diffraction slot and sharp edges at the mouth area, and so may set the alarms ringing in many a horn-audiophiles’ head, but they actually sound very smooth after being properly implemented with mentioned DSP filter-actions above.

Good phrase - "alarms ringing" since that's what the sharp edges cause worry of - ringing. I get the impression from my listening that the ringing back to the throat is generally fast enough that it doesn't cause the kinds of issues that I thought - peaky, ear piercing response types of sounds, although perhaps it can if the horn is big enough. I've heard some of the really big diffraction horns bothered people in the past but it could be they just weren't well equalized. So I think I agree with you that properly equalized diffraction throat horns can still sound quite smooth and natural, although some imaging and detail might be obscured. The better high frequency dispersion may be more than worth it in many scenarios. 

I always thought it was slots or discontinuities in the THROAT of a horn that could often cause a “spitty” or sibilant sound compared to an identical horn with a smooth throat…

@johnk wrote:

I prefer high efficiency but I don’t undersize my systems so I get bass into the 20-30hz range on most systems. I find higher eff designs to have a more realistic sound quality if done right. But many are too compromised in size. But sadly so are most of the loudspeakers offered today. Shipping costs and material costs all lead to smaller and smaller designs. I get 1 tear in my eye at audio shops it’s all too small.

My sentiment exactly!

Also, per the comments above regarding horn speakers not imaging, my JBL hybrid horn speakers image well. The JBLs have an efficiency of 2.7% they were manufactured in 1981. Happy imaging! 😎

Mike

 

 

I've had many fine speakers over the years & while there are no hard & fast rules regarding music reproduction, I think that generally high efficiency speakers sound more like live music than lower ones. Its not just a simple matter of more watts to compensate for lower efficiency. The dynamics & transient response for myself are what differentiate good sounding "hifi" systems to ones that actually can sound like live music. I've heard a few, very expensive lower efficiency speakers driven by very expensive heroic, 100 lb. + , 2 + foot long amps that can do this but you can buy one very nice, very fast Ferrari or McLaren for that kind of money (w/ a decent sounding stereo system...) of two or three pretty nice German, decked out sedans (also w/ good sound systems -  for a car).  Crazy $$ for a few lucky folks.

Of course, as others mentioned to get good bass that can play loudly & high efficiency, he need to have a large speaker w/ a large woofer or two which can also be somewhat pricey. Along w/ that can come some limitations at the frequency extremes & coloration, especially from some horn loaded speakers. I think there is a trend today to connect multiple smaller woofers in parallel to gain efficiency at the expense of reasonable impedance loads which can cause undue strain on less than very good amps & thus potential distortion. 

I found & now own what I consider to be an excellent balance between all these factors, the Volti Audio Rivals. They're made in TN,  "reasonably "priced (about $15K), substantial but not crazy large & sound excellent. They're horn loaded midrange & tweeter w/ a 15" paper cone ported woofer. They're very dynamic, big sound but also quick & detailed, image well w/ very solid bass although not "bat frequency extended" on the high end. They can fill a large room w/ very good sound like few other speakers can at anywhere near their price range. With a good tube amp, they sound like live music & are tons of fun!

@audiokinesis wrote:

[...]

All of the above speculative explanations are unlikely, perhaps even highly unlikely, which brings me back around to "I don’t know".

Sorry about that!

Duke

No need to be sorry - on the contrary, thanks for taking the time to investigate on the matter! And to come up with some theories that could explain why no EQ-gain in the upper octaves with my CD horns/comp. drivers is necessary. I’ve had several people (audiophiles most of them) listen to my setup, and none of them have addressed (even when eventually asked) a lacking HF performance/extension or a possible frequency imbalance, though I can say for my own part that the very smidgen of upper bat territory range they don’t cover, and I’m fine with that.

@asctim wrote:

Good phrase - "alarms ringing" since that’s what the sharp edges cause worry of - ringing. I get the impression from my listening that the ringing back to the throat is generally fast enough that it doesn’t cause the kinds of issues that I thought - peaky, ear piercing response types of sounds, although perhaps it can if the horn is big enough. I’ve heard some of the really big diffraction horns bothered people in the past but it could be they just weren’t well equalized. So I think I agree with you that properly equalized diffraction throat horns can still sound quite smooth and natural, although some imaging and detail might be obscured. The better high frequency dispersion may be more than worth it in many scenarios.

Thanks for your insights. Many factors certainly come into play on how to properly assess a given horn/comp. driver combo, and in this case a Constant Directivity horn with a diffraction slot and relatively sharp (i.e.: not large diameter rounded) mouth edges. Some people on principle just shy away from such a horn type, which is a shame being there are several examples of them sounding very, very good. It’s mostly about the implementation, size is a factor (i.e.: the bigger ones, many things being equal, sound less like horns and often downright awesome), and the intended usage. You could be right on details/imaging being slightly obscured here, but my advice would be for people to listen first and then "judge;" much of which is passed around on the supposed deficiencies in this regard is really just speculation and assumptions, or certainly could stand the test of being evaluated more closely for the relevance and degree of such speculated deficiencies.

@johnnycamp5 wrote:

I always thought it was slots or discontinuities in the THROAT of a horn that could often cause a “spitty” or sibilant sound compared to an identical horn with a smooth throat…

Relative to the specific horn in question these "spitty" effects, if they do occur, would normally only do so at prodigious SPL’s. The levels where this might happen is close to bonkers, with my own EV horns (and only assuming the effect will happen, if it even will) this would be somewhat past 120dB’s, far exceeding what most sane individuals would expose themselves to.

IMO people can get trapped in the rabbit hole of measurements not only in speakers but every component. Music is enjoyed through your ears not through stats snd graphs on paper. I do not care What the numbers are I do care how it sounds to my ears. Go with what sounds good to your ears. Then sit back and enjoy the music!

I have been listening to the newest Horning Aristotle Ellipse PM65 speakers. They have a rated 96db efficiency, but in real life are very easy to drive. A few watts will do it beautifully. It is a horn loaded hybrid design that is not very large. This speaker is incredibly fast, dynamic and so pure sounding. They offer most all of the sonic benefits of a large, fully loaded horn design in a more traditional form factor a size.

In general,  I also find higher efficiency speakers sound more real and lifelike, at least to my ears. Here is a link:

 

 

@charles1dad , ESLs do not necessarily require large SS amplifiers. You can also use a large tube amp like the Atma-Sphere MA 2. 

The difference between my own personal way of thinking about this is simple, There is accuracy and there is "taste." Accuracy includes the whole system including the room. I always start with accuracy and throw my taste on top at the end. Most people start with taste and never really deal with accuracy which requires choosing the right equipment for the right reasons and the hardware to measure and adjust it's performance in the room. So then why ESLs, more accurately why 8 foot dipole ESLs? They have the lowest levels of distortion within the audio band and coloration of any type of speaker. Dipole linear arrays have ideal dispersion characteristics for preventing detrimental room interaction. Linear arrays broadcast sound more efficiently which is why they are used at large rock concerts. The only serious problem that should be dealt with is dipole ESLs do not like making bass. Below 100 Hz should be sent to a driver specifically designed to make low bass and doing so decreases distortion throughout the rest of the audio band to a significant degree and increases headroom to the point where the system is capable of doing an effortless 105 dB, not that you should.

A really excellent thread!I purchased my first high efficiency speakers a year ago and will never go back.The "lit from within" observation previously mentioned is addictive.

Agreed this is an excellent thread! The reason for my love for high efficiency is still a bit of a mystery for me. I've been thinking a lot about directivity being a big factor - a better direct to reflected sound ratio than a typical lower efficiency speaker. This will make the speaker seem quieter in a given room but then the efficiency allows the apparent volume to come back up, so transients are clearer. Listening to good direct radiators of lower efficiency at close distance should provide a similar effect according to this logic, and to my ears it largely does, only that it scales down so the dynamic contrasts aren't as impressive as when the same effect occurs at greater distances. 

@grannyring I also find higher efficiency speakers sound more real and lifelike, at least to my ears. Here is a link

Pretty much the same conclusion I arrived at quite some time ago. Yet, I can respect /appreciate the different approach and opinion of @mijostyn and others. When it’s all said and done, It is what moves you the most.
 

Anyway that’s my philosophical stance with constructing a home audio system. I try to achieve as much realism within my means.

Charles

@charles1dad , Yes, realism could be the final goal. How do you get to realism? How realistic can you get? Many of us do not even think about realistic. It is viewed as an unrealistic goal. Not true at all. Given the right recording a system can sound scary realistic and I do not mean with just an acoustic guitar either. It can be done with full on rock and jazz. It can be done with equipment that is not Luxury Audio. There are also several roads that lead to Rome. Of the three systems that met my criteria for realism one was a three way dynamic system and the other two were based on very different types of ESL. Three systems out of hundreds including the ones I designed (under the wishes and pocketbook of persons usually more interested in fancy decor and artwork than music.)  Many of them were owned by audiophile friends. Some of them were mine. 

Among audiophiles there is significant variance in expectations and priorities. Someone is bound and determined to set himself up with a SET amp because he heard one he thought sounded good, in a totally different environment than his own listening room. Now he can't get the volume he would like on some recordings so he goes out and gets a set of high efficiency loudspeakers which are not capable of performing as well as the ones he had (with the right amp) but they go loud and he is happy. Then there is the confusion generated by unintentional psychological disinformation. There are people who will swear their system improved by putting their cables on elevators. All of a sudden everyone is selling cable elevators. So what is an English Major to think? While guys like my are laughing under our breath. 

Accuracy gets you in the ballpark, taste gets you to realistic, both get you evicted. 

   

Agreed @charles1dad 

@mijostyn These 8’ panels…where need they be located in relation to front and side walls? What size room approx?

The few Ive heard where mad far out into the room.…

@grannyring 

I have not heard the Horning Aristotle speakers. I have heard their larger sibling the Eufrodites on 2 separate occasions. So I understand your enthusiasm.It doesn’t require much power to make them sing. More importance placed on the quality of the watts driving them. 🙂

Charles

High sensitivity speakers sound more like live music.

My speakers are home-brew, look like Klipsch Lascala on steroids, average sensitivity is 105dB and I tri-amp with an analogue active crossover (subs, bass/low mids, mids/treble)

 

For me the micro and macro dynamics associated with high sensitivity (100dB+) is something I could never do without, and being able to use very low power amps is a definite advantage

BUT

-big horn systems image differently, you either love it or hate it

-ANY noise or distortion will be MAGNIFIED and unbearable - this is real - any RFI / EMI, any noise on the AC lines, anything from the outside world (or from your electronics) that would mostly stay hidden on a low sensitivity system will be exposed and you will have to deal with it or live with it!

-caution with gain structure is important, otherwise say hello to noise (see above remark) and hello to all the issues some preamps can have when used with the volume potentiometer at the lowest settings (bad stereo tracking, loss of dynamics and definition, etc) YMMV depending on the quality of your preamp(section), but shouldn’t be overlooked

Great that there are lots of comments and examples here for your question...  I have to agree with many here regarding higher efficiency speakers over inefficient ones.  I've had both types, and in each case, micro-detail has always been notably better with higher sensitivity speakers.  I had 89db speakers and using the same electronics, my friend brought his 98db speakers in and with my exact same electronics, you could immediately hear the micro-detail difference just queueing the stylus !  I was astonished as the music seemed more real and alive.  I sold my beloved speakers soon after and bought 94db ones and experienced that same more alive, real and micro-dynamic improvements.  Then moving to much lower powered amplifiers (ie...  less components that "touch" the signal) even more micro-detail was apparent.  So now, I am ordering my last set of speakers at 101db efficiency to take advantage of my low-powered amplifiers.  I don't listen at very high volumes but it's the details, soundstage, and realistic portrayal that really capture me.  There's only one exception to the inefficient speakers I've found to those that are efficient that I've experienced and that's the Magnapans.  I heard music played on the 3.7i's and the upper mid-range/treble was some of the most accurate and micro-detailed I've ever heard.  This is proof that there are exceptions to every rule, and in the case of the Maggies, the extremely light weight diaphragm is the reason for the terrific micro-detail, despite their inefficiencies.  Everyone's tastes in music and how it's portrayed is different, and that includes speakers and corresponding electronics, so if you enjoy how your music is reproduced with your stuff, that is what's most important.  .  

 

charles1dad 8,981 posts 08-10-2022 at 09:34pm  @sbank  Duke is wise. Agreed, and humble. Charles"   Duke is also very willing to be helpful to those less knowledgeable than him.  Back in 2004 I was seriously considering building a huge d'Appolito system with Oris 150 horns flanked above and below with 15" open baffle woofers.  Duke was very forthcoming with knowledge and advice on what I could expect if I built them.  He couldn't have been more helpful if I had been paying him a consultation fee.

I also prefer high efficiency speakers but they have big/many woofers to produce bass (Legacy Focus and Signature IIIs).  Noise is more prominent than lower efficiency speakers but so what, dynamics are easy to get, especially when loud.  I play my jazz and classical music up to 95 db all the time in a custom built listening room (expensive).   Average volume in the 80s db.   

Harbeth 40 series (top) speakers are rated inefficient with high impedance.  Relatively easy to drive with moderate power.  They never failed to sound excellent, especially nice in the mids.   At shows, no one says best in show but always musical as the mid-range is 90% of the music.   Much like Von Schweikert speakers.  I would rather own Tannoy's than most horns or stats (had stats for 20 years in my youth).   My wite of 24 years hated the big stats (ML Monolith IIIs) as they had limited dynamics, beamy, limited bass in particular.  I've moved on then to dynamic speakers and not return to stats ever (including good sounding Soundlabs).  

@mijostyn  I heard the Carver Amazing line array speaker.  No bass.  Wonderful spacious sound and imaging in the mids and highs.  Don't know if it would work in my room.   

I heard the Volti Rivals as did my friends at a show and stayed for 1/2 hour.   Most satisfying horn speaker sound yet.  

Best sound/music reproduction ever was the $1+ million Von Schweikert Ultra 11 and 9 at shows.  No demerits, sounded as perfect as I'd want for every time of music (agreed by countless reviewers/listeners over the years).  They are bigger moderately efficient designs with lots of drivers/bass.  The older designs were just as efficient but smaller speakers requiring only moderate power 25 to 100 watts (VR series speakers). 

@mijostyn --

The best performance comes from electrostatic speakers. They are generally mid efficiency speakers but are very amps sensitive and owner sensitive. Otherwise it is 6 of one 1/2 dozen of the other. The best performance I have heard come out of dynamic loudspeakers came from inefficient speakers driven by huge amplifiers.

One of the best setups I’ve heard comprise rather inefficient waveguide-fitted "dynamic loudspeakers" (S.P. Tech Revelation, actively configured and subs augmented). It’s the whole shebang; listening room, components chosen in every department, modifications here and there - just overall brilliant implementation by a guy who’s a total wizard in this field like none other I know. He assisted Bob Smith in the development of the S.P. Techs, has a tech background in electronics, years of experience in a high-end audio shop, crazy good ears. All this to say that whatever speaker principle he would be handed with complementary gear and all, he’d make it sound absolutely great I’m sure with mods and what not. It would be interesting though to see the absolute "level of perfection" he could wring out with whatever speaker principle he’d be given, but it’s a process that doesn’t come overnight.

Generally though low efficiency, direct radiating and not least passively configured dynamic loudspeakers (even with huge amps, which are really just a symptom of a severe bottleneck in the chain: the passively driven low eff. speakers) are at the bottom of my speaker ranking, then electrostatic speakers (which I haven’t heard actively driven nor as floor-to-ceiling height models like your Sound Labs), and at the top (no surprise there) are large(!) high eff. horn-loaded speakers, be they hybrids or all-horns. Those have been the best where they were fully actively driven with DSP filtering and solid state amps, actually, and not the perhaps more common pairing with low wattage SET’s or the likes as passively configured speakers.

You may feel inclined to give me the rundown on how I haven’t yet risen to the level of accuracy, but I’d dodge such a suggestion or even as a bluntly stated fact with mere indifference; I know what I’m hearing, I have my (live) references and preferences for how to rather effectively emulate such a ref. in vital areas, and not too few years of experience under my belt. I have my tastes (i.e.: preferences), sure - so do you - and the fully actively configured high eff. large horn-loaded approach just ticks off most of the core "pillars" in sound reproduction with the least bottleneck-feel to it to my ears. Even my friend’s S.P. Tech setup mentioned above, as great as it is, comes up short in several areas compared to my own ditto (and I’m just honest here; to hell with modesty), even though it’s not as well implemented overall as his system. Tonally though our setups are very much alike, which is interesting given the differences with our speakers in particular, but on the other hand it may not come as a surprise being that we share core sonic preferences, and also that he's been instrumental in the tuning process of my own system. 

lowest eficiency is bad for my single ended el84

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.

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.

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.

 

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.

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

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

@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.

SET amplifiers are about as silly as cable elevators.

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 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.

@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.

@mijostyn wrote:

SET amplifiers are about as silly as cable elevators.

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