Great, great article alexberger! I agree and believe that this is an issue that is deliberately ignored. I have owned many different speakers and can say from experience that I have never experienced the sense (and sound) of ease and flow that comes from a well designed high efficiency speaker. I'm like many other audio guys who find big powerful amps sexy and desirable, but there really shouldn't be the need for the most powerful ones.
Low Sensitivity Speakers Compression Issue.
Main stream Hi-end producers, audio reviewers and sellers push low sensitivity tower speakers and high power amplifier solution to audiophile society as "reference" low distortion solution.
My experience shows me that this solution doesn't work.
I had myself Dynaudio Audience 60 speakers. These speakers was my worth purchase in audio.
These speakers sound horribly compressed. They sounded completely different on different volumes.
I have listened many different low sensitivity tower speakers and high power amplifier in audio shows, dealers and people houses. This kind speakers ALWAYS sound compressed even with 1000w amplifiers.
I heard about TD in speakers. This distortion are not linear, because they have a time inertia.
Here is I found a very good article written by Derek Alexander-Wilson that enplanes this issue:
https://www.linkedin.com/pulse/power-compression-vs-thermal-distortion-loudspeaker-alexander-wilson/
My experience shows me that this solution doesn't work.
I had myself Dynaudio Audience 60 speakers. These speakers was my worth purchase in audio.
These speakers sound horribly compressed. They sounded completely different on different volumes.
I have listened many different low sensitivity tower speakers and high power amplifier in audio shows, dealers and people houses. This kind speakers ALWAYS sound compressed even with 1000w amplifiers.
I heard about TD in speakers. This distortion are not linear, because they have a time inertia.
Here is I found a very good article written by Derek Alexander-Wilson that enplanes this issue:
https://www.linkedin.com/pulse/power-compression-vs-thermal-distortion-loudspeaker-alexander-wilson/
"Power compression Vs Thermal distortion
Power compression is the common term for one of the audible effects of voice coil heating / overheating, i.e. when the voice coil reaches its maximum power handling limit trying to ram more power in is sonic train crash…It does not get any louder just compressed and grossly distorted.
This effect is better described as “Thermal Distortion” (TD) and is much more serious than just a maximum power handling limitation or side effect…..TD is a huge problem, overlooked or deliberately ignored by most manufacturers as there is no easy (low cost) solution and TD is audible and measurable most of the time at most power levels…!
TD is caused by the conductive metal (aluminium, copper or silver) voice coil getting hotter when you pass electrical energy through it….The more power you pass through it the hotter the metal gets….The hotter the metal gets the more the electrical resistance increases….The efficiency goes down and you need to ram in more and more power for smaller and smaller increases in SPL….a very vicious circle.
The vast majority of loudspeaker drivers are severely “under voice coiled” and nearly all suffer from massive audible and measurable TD even at medium power handling levels, long before maximum power where audible “power compression” kicks in.
Taking a look at the relationship between voice coil power handling and voice coil heating reveals that long before audible power compression becomes an issue, TD is a serious problem….So widespread that the entire audio industry accepts it as standard and never questions it.
TD creeps into sound reproduction just like harmonic or inter-modulation distortion from low power levels and gets worse the higher the SPL’s….Far more serious than the simple “loss of sensitivity” at max power as loudspeaker driver describe it.
TD causes severe program dependent tonal imbalances in multi-way active speakers and the effect is even worse in passive loudspeakers.
Room temp to 120 degrees C
Taking an example of a voice coil using 10 meters of 0.2mm Copper with a typical resistance of 5.5 Ohm at 20 degrees C.
Apply power (music signal) & the voice coil jumps to 120°C and the resistance rises to approx. 7.5 Ohm….Now the resulting current flow through the voice coil drops by approx. 35% ….So does the SPL….This is a 35% distortion!
Orders of magnitude worse than the usual suspects of THD or IMD which loudspeaker manufacturers like to quote.
With passive crossovers in multi way systems thermal power compression will shift XO frequencies when the voice coil resistance changes – resulting in summation errors between the two drivers involved, depending on program and listening level.
The same holds true for notching out resonances or compensating impedance….The more complex the passive crossover the worse the TD effect becomes.
Why 120 degrees C?
This is a safe or medium range voice coil temperature, many voice coils hit double or triple this temperature on a regular basis.
The energy involved is as follows:
The weight of our VC wire is slightly below 3g if we calculate length multiplied by cross sectional area multiplied by specific mass of copper.
We require approx. 1 Watt for 1 sec for each Kelvin temperature increase (no cooling assumed here), looking at the thermal material constants for copper
To heat up this < 3g of copper wire our voice coil is made from, we only need 10 sec of 10W input to finally arrive at a 100°C increase – or – if we have fortissimo playing – a very short 1 sec of 100W input.
Well within the realms of average….
Now if you want to enjoy your fortissimo at 115dB SPL and given your speaker would be 95dB / W / m - well - after one (!) single second you have reached 35% of distortion – given your speaker to be 105dB sensitive you can enjoy your fortissimo of 115db SPL a fantastic long 10 (!) seconds until you end up at reaching 35% distortion.
Obviously the higher the loudspeaker sensitivity the lower the TD effects, and the better the voice coil cooling the lower the TD effects. Most “raw” audiophile loudspeaker drivers struggle to exceed 89dB over their working range, Pro audio drivers average out around 94 dB to 95dB SPL for 1 watt at 1 meter over their working bandwidth.
Real world voice coil cooling inside loudspeaker cabinets is very limited and varies from almost zero in a small sealed box with small magnet / motor to reasonable in large vented cabinets with huge heavy ferrite magnets.
But still cooling down from a 100Ws input will take much longer than the near instantaneous heating up….
Using a single layer 50mm voice coil with a height of 13mm with no isolating former (Kapton or Nomex...) is the most optimistic scenario.
This will provide a heat dissipation area of around 40 square cm. A two layer voice coils will half the effective radiating area & a four layer voice coil reduces effective radiating area by a factor of 4!
Again, being optimistic & assuming the surrounding magnet structure remains at 20°C while the voice coil already has reached 120°C the heat dissipation will be approx. 3W.
This means the decay from our 35% distortion fortissimo would last around 30 sec. Unfortunately this does not hold true - because – if the voice coil is cooled down to 70°C (half way down) then there is only about 1W cooling through radiation left (again optimistically assuming the surrounding magnet structure still to be at 20°C), further stretching the time of distortion decay.
Using an aluminium former would help to enlarge the radiating area of the coil itself but the need to minimise moving mass forces designers to use ultra-thin aluminium which cannot support massive heat transport
Forced air / convection cooling will help but pianissimo follows fortissimo - you only have forced cooling due to voice coil and membrane movement during fortissimo…
The bottom line is TD is a massive problem….The elephant in the room.
Currently the best ways to minimise the effects are:
(1) Use an active crossover.
(2) Select loudspeaker drivers with the largest voice coils…Bigger is better.
(3) Single layer voice coils are best, two layers bad, 4 layers worst.
(4) Aluminium voice coil formers may help, but they have other sonic downsides compared to Kapton or Nomex."
80 responses Add your response
Thank you.
@roxy54 , I'm pleased to know that other people knew about this problem. The actual article was written by Derek Alexander-Wilson. I like high sensitivity speakers. IMHO they have a lot of advantages: 1. They sound alive, musical. 2. The soundstage has a real size. 3. You can listen them on high volume without fatigue. 4. You can use highest quality most natural and transparent amplifiers like tube SET amplifiers (300B, 2a3, 45, ad1,...) or First Watt SIT transistor amplifiers. The drawback of high sensitivity speakers is a very deep bass. I know that people who want to have dynamic sounded system with a deep bass use two solutions: 1. Array with a big number of bass drivers. A big power is distributed between a number of drivers that decreases TD. 2. Sub bass horns. Both these solution are too expensive. So I chose for myself a real dynamic over deep bass. Regards, Alex. |
IMO/IME low efficiency speakers are next door to criminal. On top of the thermal distortion issue, they cause you to need a high powered amp, and IME one of those that actually sounds like music is a rare beast indeed. Also IME higher efficiency speakers are not only lower distortion, they are also faster. This is especially true if the magnet structure is field coil powered. As a result, a system with low efficiency speakers and a high powered amp can't seem to keep up with a higher efficiency speaker and an amplifier of considerably less power. I've seen this play out many times and the compression/lack of dynamic impact makes it hard for me to take lower efficiency speakers seriously. My speakers go down to 20Hz and are 97dB 1 watt/1 meter- no loss of bass performance... |
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Hi @viridian , I heard first about TD in speakers and transistor amplifiers from Russian audio designer and guru - Anatoly Markovich Lichnitsky. This person liked to listen mono records (mostly classical from 78RPM era) and didn’t care about all audiophile stuff like soundstage, imagined, bass slam,... Many years ago my friends and me couple time a week went to listen systems of different audiophiles in our region. We listened different box, electrostatic and planar speakers. And ones we went to one person who had big horn system with Lowther PM4 speakers and 15 inch EV mid bass speakers. It was a culture shock for us. We went back home and can’t listened our home systems during a long period of time. Since this visit, low sensitivity speakers did not interest me. Regards, Alex. |
Gentlemen...the phrases "high sensitivity" and "high efficiency" have been bandied back and forth as if they are interchangeable, which any audiophile worth his salt knows that, indeed, they are not. For the purposes of this discussion, let's settle on "high sensitivity" as the correct choice. Please continue. |
I would say that the it went so far that the audio magazines adversely changed the design of speakers and the values of the designers. The tail wagging the dog.^^ This. All transistor amplifiers (maybe, except pure class A) have thermal distortion.Class D avoids this problem. Gentlemen...the phrases "high sensitivity" and "high efficiency" have been bandied back and forth as if they are interchangeable, which any audiophile worth his salt knows that, indeed, they are not. For the purposes of this discussion, let's settle on "high sensitivity" as the correct choice. You can increase sensitivity simply by reducing impedance, so in this conversation 'efficiency' is probably a more useful expression. |
If you put two systems together the one that is loudest will always get the nod. A similar situation exists for dynamics. Distortion is almost never a good thing excepting maybe small levels of low even ordered harmonic distortion depending on your mindset. You can distort dynamics also. Some of the horn systems I have heard put your head in the snare drum. Very surrealistic (Pillow). I agree that most systems are shy of realistic dynamics but probably not from compression as they are not being run hard enough to overheat their voice coils. Electrostats do not heat up. Eventually the transformer saturates which I suppose is a similar problem. You can design a relatively inefficient speaker that is plenty dynamic as long as you have the power to drive it. Good power is expensive. You can have a well designed electrostatic system that is very dynamic and to my ears in a more natural way than the horn systems I have heard. I admit that I have not heard the majority of horn systems out there. Efficient speakers are a bonus, power is expensive. If I were faced with two equally good sounding speakers I would always take the more efficient of the two assuming the expense of buying the system were close. It all comes down to what you want to hear,matching components appropriately and managing the acoustic environment. Alex my guess is that you were blown away by a caricature of a music system. Volume and chest pounding do not a realistic system make. But it is impressive. |
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Kosst, I think we are sort of saying the same thing except dynamics are not so much a matter of amplitude but I suppose the amplitude of the transient attack which is not necessarily something you hear but something you feel. And, not just with you body but with your ears. If I push the volume loud enough your ears will hurt. Pain is not hearing. It is a somatic sensation which your ears are also wired for along with balance and orientation. Tomic I am not sure what you are saying. There are good and bad examples of each type of speaker. What I was saying is that people are automatically drawn to certain characteristics like volume, dynamics and brightness even though they may be deviations from accurate sound. I want life like tonal balance, life like dynamics and a life like image. Not more or less, bigger or smaller. Obviously in most instances these characteristics are hard to define especially with electrified modern music. But with acoustic instruments and percussion you can get a very good idea if you have taught yourself what to listen for. |
I don't say all high efficiency speakers are good and all low sensitivity speakers are bad. For example, I like Harbeth and Spendor Classic speakers. What is interesting they sound much more dynamic compared to similar efficiency speakers (probably because these companies don't lie in their product specifications). But I talk about dynamic. I'm getting mad when some audio sellers, reviewers and producers talk that 85dB speakers with 1000 Watt amplifier can give a real, uncompressed dynamics. It is simply not true. The same according tone. Yes, there are a lot of natural sounding low efficiency speakers and you can find many examples of high efficiency speakers with not natural sound. But I can't say that for sensitivity you have to sacrifice a natural ton. In most cases, paper cone give more natural tone. And most paper cone drivers are more sensitive than kevlar and plastic drivers. |
You cannot have enough real dynamic range, as it’s the real thing. Different story if you’ve added and DR Expander circuit, then it’s false. All noises we hear out in the world have "real" dynamic range, whether it’s a A380 flying over head, or a fly grooming it’s face with it’s front legs. Why some recording engineers are obsessed with compressing our music is beyond me, it's just for the earbud listeners and car radio that it does it have an advantage. Not one of her albums hasn’t been butchered this way, such a shame, for this great voice.
http://dr.loudness-war.info/album/view/159466
http://dr.loudness-war.info/album/view/98834
They didn’t bucher too much the 25 album on vinyl though. http://dr.loudness-war.info/album/view/142281
Or the 21 unmastered download, too much either. http://dr.loudness-war.info/album/view/116828
Cheers George |
Highly-dynamic and un-dynamic are relative terms. Anyone care to name speakers of either type he considers prime examples? Klipsch and other horn-designs are sure to be first on the highly-dynamic side, but how about non-horn speakers? I imagine Maggies will be high on the other side, though lovers of that design might not totally agree. I find that ESL's make concerns about dynamics disappear; the speakers sound so "quick", their abilities at micro-dynamics are SO much better than with any other type, that macro-dynamics become less important. Just my point-of-view. |
Eva is belting out Nightbird in my room right now and while I have 1.2 KW available perside in a bi amp configuration, I am sure I am not using much of it. No emitter resistor and just 5 parts in the amp signal path is probably MUCH more important ....... join us over on the music thread, forget the gear wars..... not sure what I even doing here anymore..ha |
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The OP is attempting to back up his personal sonic preferences with a theory that may or may not be valid. I have developed the exact opposite listening preference - I generally prefer the sound of low sensitivity speakers. High sensitivity speakers, particularly horn speakers, generally sound artificial to me. I have certainly heard exceptions but moderate to low sensitivity cone driver speakers sound more coherent and more like real music. Interestingly, one of the best speakers I have heard at an audio show were Dynaudio Contour 60's at Tampa. There were a couple horn speakers driven by tube amps that sounded like a joke. I couldn't imagine owning them. In all fairness, there were also some horn speakers that sounded wonderful. We're skating on thin ice when we attempt to leverage our personal audio preferences into broad statements that one technology is inherently better than another. I also take offense regarding the idea that the audio press has brainwashed me and a number of speaker designers into liking one type of speaker over another. Excuse me, I have ears just like you do and if I like different stuff than you do it doesn't make me stupid or wrong. You can come up with a negative technical argument for absolutely any audio design. Horn speakers and low power tube electronics all have their own technical problems. If you like the sound of a particular type of gear then good for you. I'm not going to try to tell you that your favorite audio components are inferior from a design standpoint. |
kenjit If you are playing at a low volume then that will define the maximum loudness which will limit the dynamic range. Actually that’s incorrect. As I just said, dynamic range is independent of loudness. It’s a ratio. Thus, dynamic range per se doesn’t change as you raise or lower the volume, all things being equal. I.e., you can control the volume but you can’t control dynamic range. |
Even though most of this is accurate, alot of it is also out of context.... Listening to speakers at 115db, Really? Then, do all drivers heat up in the fashion that have been outlined? Of course not. Quite a bit is based on the amplifier driving it, distortion levels & thd at the level that the individual driver is being pushed.... Crossover frequency on each driver limits the amount of current to that driver. How big is the drivers coil, its excursion limits, is it vented, does it have ferrofluid. I'm not arguing the point, efficiency and sensitivity do wonders for dynamics and will definitely cut down on thermal compression that develops. Again, the above, overall is true, but to alot of guys who don't truly understand speaker design will send them down a road of worry that just does not need to happen. I hope this helps someone out there, Tim |
The problem is that ears are far more sensitive to tone than amplitudetone comes from micro and macro combined dynamic positive leading edge temporal and level positioning. The implication being that amplitude is no less critical to the set of conditions in situ than anything else. As this is how our ears function. pretty well 100% of how we hear happens in this way. It’s the why of how we can hear clocking jitter, or transient distortions added in via fuses or cabling, or amplifiers, etc. This is the short answer. The complex fully fleshed out answer to the follow up questions -which are generally issued in quizzical anger to my initial statement-.....is what we learn, over time. If one does not get it, then, please read up on the subjects involved. And ...two posts above, Geoff says the critical caveat: " all things being equal." Which of course, with a single minuscule twitch of the volume position, everything goes unequal in all kinds of directions, in each piece of equipment in the given audio chain....and then heard as a whole. added to that, is the issue of the ear being a living breathing changeable mutable device where we can alter it's filtering and window of awareness, on the fly and we can do it all the time. If one does not hear these things, then learn to manipulate the ear's function, ie to develop the skill of hearing. No less a critical function to learn as walking or running on a professional level. Both conscious and unconscious, with no two sets of innate capacity or skill learning potential - being the same. We all hear and see the idea of 'orange' differently on the internal level but agree with the basic shared nomenclature. |
Can someone mention a few models of these two classes of speakers discussed here? Just to have some reference for those of us not familiar with this issue. Dynaudio Audience 60 is obviously mentioned as "low sensitivity tower".
As noisy as it is, and nobody wants it flying over her/his head, A380 is relatively well-known for being much more quiet than most of the other planes. It was one of its bragging rights. https://www.heathrow.com/file_source/HeathrowNoise/Static/CAA_A380_Noise_Levels.pdf |
Here are my fresh memories from Montreal audio show this year. I listened a number of very high efficiency speakers systems there. There are different solutions for different price and with different kind of sound: Tune Audio Marvel - https://www.youtube.com/watch?v=JCLuH_NeVgI Avantgarde Uno - https://www.youtube.com/watch?v=4s8AeLSdk2M Avantgarde Duo - https://www.youtube.com/watch?v=-cjmSP574Y4 Tri-Audio - https://www.youtube.com/watch?v=oed2nHBWVJY I liked Tune Audio Marvel system a lot. It was very good in both tone and dynamic. IMHO the best system in Montreal Audio Fest this year. Avantgarde systems has a huge sound, with very good dynamic and a lot of details. But I don’t like tone and the quality of bass. Tri-Audio was a nice system and very good value for money. It sounded good but their mid-range drivers have some coloration, typical for full range drivers with a visor. |
If you are playing at a low volume then that will define the maximum loudness which will limit the dynamic rangeIn a good system the "ratio" of the quietest musical passage to the loudest one should be the same at low level listening or at high level listening, without colourations. Avantgarde systems has a huge sound, with very good dynamic and a lot of details. But I don’t like tone and the quality of bass. Yes for me this has always been the downfall of high sensitivity speakers, they are usually too coloured for me. If you can live with that fine, but I’ve always chased the opposite, I’d sacrifice a little sensitivity for neutrality and transparency. Cheers George |
Performing on stages with Altec Voice-Of-The-Theater PA speakers starting at a young age (before I heard my first audiophile speakers), I had a bad first impression and opinion of horn loudspeakers. But the VOTT was designed for a different purpose than are hi-fi speakers. When I did started hearing hi-fi models (late 60’s), I still heard in varying degrees the colored sound (what J. Gordon Holt coined "cupped hands vowel colorations") of PA speakers. One glaring example was the JBL Century L-100 (recently reintroduced), which I found absolutely unlistenable. Hearing my first ESL’s in 1971 (the Infinity Servo-Static, and the RTR tweeters in the ESS Transtatic) set my standards for "uncolored" (think color temperature in a video monitor) sound pretty high. Same for the quality Gordon called "liquid transparency"; grain-free, like Kodak 25 ASA film. I haven’t heard many high-sensitivity dynamic (cone) speakers, so I’m very interested in any of them that are free of the colorations of horns. Or in any modern horns that are free of the classic horn colorations. Any loudspeaker that changes the timbre of a vocalist is immediately crossed off my list; for me, that is the one mortal sin in a loudspeaker! I have tapes I recorded myself using a pair of omni small diaphragm condenser mics plugged into a Revox A-77, both of spoken voice and a Jump Blues Band I was a member of. Comparing the sound of my son’s voice to it reproduced by a loudspeaker is a brutal test! Same for the sound of my Gretsch drumset and Paiste 602 cymbals, our two sax players’ tenor and baritone Selmers, the upright piano, the Fender Telecaster Bass, the Gibson 1-pickup hollowbody of the other players, and the vocalists (a white man and black woman). |
Hi @georgehifi , Yes for me this has always been the downfall of high sensitivity speakers, they are usually too coloured for me. I gave here a good sounded high sensitivity speaker example - Tune Audio Marvel. Most of Tannoy speakers are natural in term of tone. Audio Note speakers are very good in term of tone. I also like my vintage Altec 604E. They are not as extended in high frequencies and sub bass as best modern speakers. But I think they overperform most of modern low-mid sensitivity speakers in term of tone. They are also transparent and have good soundstage. They are great for vocals and any kind of jazz music. I also like Harbeth and Spendor (mid-sensitive speakers) in term of tone and musicality. I listen mostly jazz and classical music. I listen a little classical rock. I don't listen any type of pop and electronic music. But all people are different, have different test and like to listen different kind of music. Regards, Alex |
teo_audio And ...two posts above, Geoff says the critical caveat: " all things being equal." Which of course, with a single minuscule twitch of the volume position, everything goes unequal in all kinds of directions, in each piece of equipment in the given audio chain....and then heard as a whole. added to that, is the issue of the ear being a living breathing changeable mutable device where we can alter it’s filtering and window of awareness, on the fly and we can do it all the time. If one does not hear these things, then learn to manipulate the ear’s function, ie to develop the skill of hearing. No less a critical function to learn as walking or running on a professional level. Both conscious and unconscious, with no two sets of innate capacity or skill learning potential - being the same. We all hear and see the idea of ’orange’ differently on the internal level but agree with the basic shared nomenclature. >>>>Merciful Minerva! What’s so difficult about staying on the subject, dynamic range vs loudness? It’s not rocket science. I don’t even know what you’re trying to say. |
I haven’t heard many high-sensitivity dynamic (cone) speakers, so I’m very interested in any of them that are free of the colorations of horns. Or in any modern horns that are free of the classic horn colorations. Any loudspeaker that changes the timbre of a vocalist is immediately crossed off my list, for me, that is the one mortal sin in a loudspeaker! Same here, but it’s not just horns that colour in hi sens speakers, many use low order xovers to get higher sens as well, and this can lead the drivers to work into their non-linear range which also cause heavy colourations. Again some don’t mind it, I don’t as I want the highest neutrality and transparency. Cheers George |
alexberger, All those links worked for me. I do not know if there are some "requirements" in design of such speakers. Of course, talking strictly about sound, there may be a lot of discussion. However, it is also understandable if majority of people do not give them much attention and decide not to buy them. All of the speakers you linked to are large and imposing. Not exactly living room friendly for most. That may play against them on the market. I know, that is a whole another topic, but just noticing. Are there any numbers we could attach to "low sensitivity" and "high sensitivity" or it is not as exact? It would be easier to distinguish between them just based on specifications. By the way, that video with Tune Audio Marvel is puzzling. Are those record covers on the floor? Are there records in them? Records on the floor? One of the first things I have ever read about audio reproduction. No records on the floor. Dust. Horizontal only on the turntable. |
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Damn @audiokinesis, I gotta get out more. ;-) The Edgar of Edgarhorn came into Brooks Berdan Ltd. regularly, but Brooks didn't seem to take him seriously, and never had a pair of the horn speakers in his shop to listen to. Near the end of his life, Brooks took a pair of Klipsch K-Horns in on trade (and a pair of Wilson WAMM"s!), but took them home for his own use. His main speaker at home was the Jadis Horns, but when I was over at his place it was usually to bring him a drumset (I was his "dealer" ;-). His wife Sheila (who now manages the shop) hired me to put a band together to play at his 50th birthday party, at which he got up on my set and played "Wipe Out". Brooks had been in a high school garage band, and hadn't played since. It was the happiest I ever saw him. |
@bdp24, thanks for the story! My understanding is that Bruce Edgar really is a rocket scientist... I think he worked at NASA, or maybe it was an aerospace company. He's as enthusiastic as a kid, and hasn't let his MS throttle back his enthusiasm. The creations of Bruce Edgar and John Wolff (Classic Audio Reproductions, now shortened to Classic Audio) inspired me to get serious about doing a high-end horn system. It was at CES 2001, I was a fairly well-established SoundLab dealer, and it was extremely rare for me to walk into a room at an audio show and hear something that I thought was competitive with the SoundLabs. Bruce and John were doing things that were very different from SoundLabs, yet very competitive I had to admit. Subsequently Earl Geddes became my mentor, and several years ago someone asked him what speakers he'd have if he didn't make his own. He said Edgarhorns. That's a pretty high compliment coming from Earl. More recently Bruce has been designing very high end, very large multi-way carbon-fiber horn speakers for a company called ESD Acoustics. Most people are put off by the price tags, but the one time I heard them (at RMAF last year) they did some things better than anything I'd ever heard before (and I only heard part of one song). I was not expecting the realism I heard from my far-off-axis location. It was great to see Bruce's ideas brought to life in a way that probably wasn't remotely feasible with normal building materials. One of my best friends, a bass guitarist turned master woodworker, is an authorized builder for Bruce's Edgarhorn systems. Duke |
My friends at NorthStar Leading the Way were the US importer of Jadis, and I had the opportunity to be the " demo person " at the NY Waldorf, 1996 Stereophile Show. It was the debut of the Eurythmie horn speakers, and they were beautiful. My understanding was Brooks Berdan was one of the 1st dealers to have them in the US, and had them set up at the store. I am wondering if the pair at home were the store demo pair, or another pair was sent to him. Anyway, an excellent speaker. |
Duke, Brooks Berdan Ltd. is in Monrovia, a 15 minute drive east of Pasadena. He had a fair number of regular customers who worked at either the Jet Propulsion Laboratory or Caltech, smart guys with good educations. A goodly number of them bought either Jadis or VTL pre and power amps from Brooks, but often chose Wilson speakers, for reasons that eluded me. No offense, Wilson lovers! It was Brooks who turned me on to the Eminent Technology LFT-8 loudspeaker and Music Reference electronics, both of which he sold. It was from his wealthy customers that I learned sound quality was often perceived in relation to how much it cost. I place a fair amount of blame for that on Harry Pearson. Bruce Edgar would come in the shop frequently, always updating the regular Saturday group of hi-fi nerds with news of his loudspeaker progress. I liked the idea of his horns being carved out of wood, as I associated the "horn sound" with that of ringing metal. I really wanted to hear a pair, but Brooks was a funny guy, very opinionated and somewhat ornery. Really good at what he did, though. Bill Johnson had him drive out to his winter home in Indian Wells (next door to Palm Desert) to set up his turntable. Brooks could find the optimum location for a pair of loudspeakers in a room faster than anyone else I’ve seen do it. Really good ears. |
Very interesting, bdp24! Sounds like a wonderful place. That would have been so much fun to attend the Saturday nerd sessions! Great that Brooks was open to that even if his own preferences were in a completely different direction. And I didn't realize Brooks Berdan LTD was still going strong. Good for Sheila and company!! Great line-up they have. I wanted to become an Eminent Technology dealer at one point but various major events intervened and I ended up becoming a manufacturer instead. Interesting you should mention wood horns... the system I'm working on right now uses wooden horns. Just finished the crossover design this morning. At least they won't have any metallic ring to them! Duke |
The solution is a line array system. Enormous efficiency, and very low thermal distortion. Each speaker in both the mid ranges and the high ranges is not asked to car more than 5% of the total load. The total distortion is very low and the dynamic range is huge. Unless you are using horns your dynamic range is limited due to the energy required to get an audible sound out of a singe speaker system to begin with. But with 25 mid ranges on each channel, for example, each one plays barely audible in the low passages but as a group they play easily heard low volume sounds. There is no lower threshold where the speaker has to have a certain power jump to be audible, and that level is too high for a quiet passage in music. Of course if you only listen to loud music this may not be a problem for you. |
Hi @glupson, All those links worked for me. I do not know if there are some "requirements" in design of such speakers. Of course, talking strictly about sound, there may be a lot of discussion. However, it is also understandable if majority of people do not give them much attention and decide not to buy them. All of the speakers you linked to are large and imposing. Not exactly living room friendly for most. That may play against them on the market. I know, that is a whole another topic, but just noticing. I don’t care what use most of people. The big part of audiophiles today listen junk pop and electronic music that we can hear at most audio show and YouTube videos. I used my Altec 604 in 200 sq feet room in the corners. Bass wasn’t boomy at all, because of very strong bass drivers magnets and as result very low Qts. I think speakers like Tune Audio Marvel can be used in very small room. In 50-60x big speakers weren’t issue. I think small speakers become the fashion because transistor amplifiers, WAF, cost reduction and marketing but not for sound quality. Why do you need to produce expansive speakers with big boxes, big paper cones with strong alnico magnets, if you can produce cheaper small drivers with plastic cones and weak magnets and your marketing people will brainwash folks that you do it not because cost reduction but for sound quality? By the way, that video with Tune Audio Marvel is puzzling. Are those record covers on the floor? Are there records in them? Records on the floor? One of the first things I have ever read about audio reproduction. No records on the floor. Dust. Horizontal only on the turntable. It was their show room in Montreal Audio Fest. |