@ramtubes ...And I didn't- hence the comment 'a lot depends on what is meant by 'instantly' ' (a word used in an earlier post by Erik Squires).
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
Tell that to owners of the Fairchild compressors like the model 670!! It uses a light bulb as part of its compression scheme. You already know how light the wire is in a voice coil. That it could heat up quickly enough to actually compress a transient peak should come as no surprise. Of course, a lot depends on what is meant by 'instantly' :) A light bulb is a very thin tungsten wire (big temp coefficient, much more then Copper on Aluminum) in a vacuum. I would not use this as an analogy. |
The OPs numbers are all made up with assumptions I would not make in a NY minuite. He has done no measurements, its all conjecture. Here is a guy who has done his homework and made some measurements. Not to say that voice coil heating isnt real, but voice coil cooling is real too. The OP is stuck on 35% distortion. Mentioned over and over and over. https://www.stereophile.com/content/hot-stuff-loudspeaker-voice-coil-temperatures-page-2#R4eshWmRTxLtTFTr.99 |
I get great imaging and depth out of my horns- as good as any ESLs or conventional box speakers. They mimic the recording. But I get why so many have poor results with horns. Older horns are not designed to work with amps of lower output impedance so with such amps they won't sound right. On top of that, it really took computer optimization to get the throat and mouth designs correct. There was a very nice horn system presented at RMAF this last year- it was a multi-way affair driven by what looked like a 5-way ampified setup complete with room correction. The horns were carbon fiber and IIRC designed by Bruce Edgar. Pricey- well into 6 figures but seamless and pinpoint imaging with plenty of stage depth. https://www.soundandvision.com/content/rmaf-2018-two-channel-heaven-audiophiles |
Hi @mijostyn , Horns can be made with very little coloration and certainly get the nod in terms of efficiency. If you are in love with low powered amps there is no better solution. However, I don't like them. I do not like them because they are point source radiators and do not broadcast a realistic sound stage. I think that most well designed drivers run within their established parameters are not going to compress anything.I think you have an experience with bad designed low powered amps. 1. Many of them use too small transformers (that have bass issues) for cost reduction. 2. A big pat of 300B SETs use very week drivers like 6SN7 (to high output impedance and low anode current). Because these design mistakes these amplifiers sound "small". I have 300B amplifier with 6F6 driver in triode. I have a big and 3D soundstage with my Altec604. Regards, Alex. |
Horns can be made with very little coloration and certainly get the nod in terms of efficiency. If you are in love with low powered amps there is no better solution. However, I don't like them. I do not like them because they are point source radiators and do not broadcast a realistic sound stage. I think that most well designed drivers run within their established parameters are not going to compress anything. If you want to worry about compression you need look no further than the dynamic compression schemes that are used when mastering discs. |
Horn colouration and efficient drivers used used outside of their linear range because of low order xovers, are "not natural" in their "tone".A lot of horn systems use 2nd or 3rd order crossovers. My system uses 6dB slopes, but the compression drivers have Kapton surrounds to allow them to have much greater excursion without breakup. So they can be crossover over with 6dB slopes and no worries. |
Yep, materials do not heat up instantly when power is dissipated.Tell that to owners of the Fairchild compressors like the model 670!! It uses a light bulb as part of its compression scheme. You already know how light the wire is in a voice coil. That it could heat up quickly enough to actually compress a transient peak should come as no surprise. Of course, a lot depends on what is meant by 'instantly' :) There is a lot of mis conception and misunderstanding about dynamic rangeYes. In about 90% of audiophile conversations, the word 'distortion' can be safely substituted for 'dynamics' without changing the substance and meaning of the conversation. This is because the ear uses higher ordered harmonics to sense sound pressure- and such harmonics are in much greater abundance in audio playback than it is with actual real music. Incidentally, this is why SETs are known for dynamics well outside of what you might expect for so little power. In reality, dynamic structure should come from the recording and thus be the same with all electronics. |
Hi @georgehifi , I think horn coloration issue was exaggerate by modern audiophiles. Why most recording studious have been using horns for monitoring, from old Tannoy, Altec and JBL to modern Ocean Ways, Tad and Kinoshita? IMHO beryllium tweeters sound more unnatural that good designed horns. When I'm listening speakers with beryllium tweeters I have fealling the someone is crumpling sheet of paper. If you don't like horns, there are very good in term of tone, high sensitive Audio Note speakers. Regards, Alex. |
Well, what I've seen was not instant, but clearly visible on tone bursts. I only quibbled over the term peak compression, because it sounded like clipping. I agree it can be a serious issue though, which can evidence itself in a variety of ways. I'm sure a lot of descriptions of speaker behavior in the press are really compression artifacts. Still, this is not the only thing to look for in a speaker, and some of the speakers I've seen designed specifically to maximize dynamic range have other issues, like loosing detail at moderate listening. I am fortunate enough to listen to speakers every day I can find little fault with in this regards. Maybe I've just gotten more forgiving. Best, E |
Erik wrote: "By the way, I’ve never seen anything about a single peak causing thermal compression, or that only the peaks are then compressed, or that everything is fine BUT the peaks due to thermals." If, as Earl Geddes says, the heating is instantaneous (even if we can’t measure it instantaneously), then it makes sense that the peaks would be affected the most. And I never said only the peaks are compressed, but if there is compression, isn't that where it would be most noticeable? And if, as Earl and Floyd Toole both say, thermal modulation has not been looked at in detail yet, it’s not surprising that you’ve never seen anything about it. And unless some big company with deep pockets decides it’s worth studying in detail, that’s unlikely to change much. Well perhaps my recording engineer friend will get his paper written and published, as apparently he has been documenting compression of peaks for decades (again, I have refrained from posting the details he shared with me because he considered that to be proprietary information). Duke |
Yep, materials do not heat up instantly when power is dissipated. I believe, but again, not an expert, that unfortunately the voice coil former upon which the voice coil is wound is usually thermally insulating. Kapton and fiberglass for example. If they were more conductive they could add to the thermal mass and increase the rate of convection to the air. Others with more knowledge of speaker motors will have to chime in here. |
By the way, I've never seen anything about a single peak causing thermal compression, or that only the peaks are then compressed, or that everything is fine BUT the peaks due to thermals. What I have seen are either non-linear drivers (due to motor, suspension, etc) or compression (of peaks and non peaks) occurring after drivers heat up, which can happen in milliseconds. |
IF thermal modulation (compression of peaks due to the instantaneous voice coil heating and resulting resistance at the onset of a transient) is a real thing, THEN there is an interesting implication about amplification choice: What if we used an amplifier that did not deliver proportionally LESS power as the voice coil resistance (and therefore load impedance) rises? This would make the loudspeaker/amp combination relatively immune to thermal modulation effects. Zero (or very low) global negative feedback amplifiers (typically tube amps but sometimes solid state) tend to deliver approximately constant power, rather than approximately constant voltage, and therefore are far less susceptible to thermal modulation effects. Here is a link to a paper on the subject: http://www.atma-sphere.com/Resources/Paradigms_in_Amplifier_Design.php Disclaimer: I’m a dealer for the amps made by the paper’s author, Ralph Karsten. Duke |
In my case I listen to AMT’s with tons of dynamic range (measured by me) and low distortion. Since I have owned this pair I find that listening to speakers which I later learn have significant compression in the tweeter is much more fatiguing than they used to be. That is, my ears seem to have become less forgiving of this characteristic, but it seems to be something I’ve learned, not an innate preference before then. |
"If memory serves, the late, great, Siegfried Linkwitz, had some very interesting oscilloscipe traces, using tone bursts, and it was in fact quite remarkable how fast thermal compression set in." That makes sense. "Another thing, there’s other types of compression, which results in easy to measure frequency response changes." Yes, the real world is a complicated place. Different drivers in a system will often have different thermal characteristics, such that the tonal balance changes with level. This change in tonal balance can be small or large. Is there a correlation between loudspeaker thermal characteristics and perceived sound quality? Again quoting Earl Geddes: "I started measuring thermal responses in loudspeakers and found that this did seem to correlate better to perceived sound quality than frequency response[!] or THD." To the best of my knowledge Toole did not include thermal characteristics in his study of the correlation between objective measurements and subjective preference, so that is a very intriguing statement. Duke |
If memory serves, the late, great,
Siegfried Linkwitz, had some very interesting oscilloscipe traces, using tone bursts, and it was in fact quite remarkable how fast thermal compression set in. Another thing, there's other types of compression, which results in easy to measure frequency response changes. That's a reason I really like the measurements from Soundsage, it is easy to see. |
@kenjit wrote: "the stereophile article says... [thermal compression] is negligible." Here is the problem with that article: It looked at temperature changes averaged out over time, rather that looking at the instantaneous spike in temperature (and thus voice coil resistance) at the onset of a transient, which is what compresses transients. From the author’s description of how the measurements were made: "For the measurements, the DC voltage across the voice-coil was recorded at intervals of 10 milliseconds with a Pico Technology ADC-212 virtual instrument oscilloscope in data-acquisition mode, using Pico’s bundled PicoLog software. The data were then smoothed using a five-second moving average calculation performed in a software utility written for the purpose." In other words, he was taking the voice coil’s temperature at 10 millisecond intervals, and then smoothing the data across a five-second moving average. So he was NOT measuring the instantaneous spikes in temperature caused by transients, but rather the cumulative effect on voice coil temperature of music spread out over time. This totally misses the target, because it is those INSTANTANEOUS temperature spikes which are responsible for thermal modulation (compression of transient peaks). Earl Geddes on the subject: "The voice coil will heat instantaneously as current is sent through it - there is no time constant. Its mean temperature has time constants but not its instantaneous temperature." The Stereophile article looked at the MEAN TEMPERATURE, and found the resulting calculated thermal effect to be negligible when averaged out over time. But the thermal effect which compresses instantaneous peaks would only show up in an examination of the INSTANTANEOUS TEMPERATURE (which might not even be possible to measure precisely). Earl continues: "How much resistance change is there from this instantaneous temperature change you should ask. It depends on the amount of metal... Thus the single factor for the instantaneous resistance modulation is the mass of the voice coil conductor." In other words the brute force approach - voice coil thermal mass - is what matters most (for a given wattage input) if the goal is minimizing thermal modulation, as others have said in this thread. Earl again: "The longer term rise in the voice coil temperature tends to be on the order of several milliseconds [which is what the Stereophile article was looking at]. The instantaneous modulation is what I am curious about as it has not really been looked at in any detail that I know of." So the Stereophile article was not looking at the thing that really matters. Earl is a leading peer-reviewed expert on the subject of distortion and distortion perception, and he invented a voice coil which has negligible increase in resistance as its temperature rises. So he is a genuine expert in this field. Duke |
There is a lot of mis conception and misunderstanding about dynamic range, The reason that many older audio components used loud controls and is now the common practice for recording technicians to compress the dynamics of recordings, is because human hearing is not equally sensitive to all frequencies at mid to low volume levels. I know we each, as individuals, like to believe that we possess some kind of incredible hearing; the truth is, regardless of how good we think our hearing is, at low volume levels (at your listening position) both high and low frequencies will be diminished and at volume levels below 30db, will seem almost non existent. Just because any given speaker measures flat at 1W/1M doesn't necessarily mean it will be more musical, eight or ten feet away, at your listening position. There is a lot to be said for Michael Greens idea of tuning. Regardless of the speaker type or design and the associated electronics and how they measure, what's important is how well your speakers and equipment produce an enjoyable musical experience in your environment at a volume level acceptable to you....Jim |
My point being, thermal compression and thermal modulation (short-term thermal compression) are real things, but unfortunately that information is not widely known in the home audio world. It’s almost like a dirty little secret that speaker manufacturers don’t want to talk about. the stereophile article says an 8% increase in resistance corresponds to a temperature increase of just under 20°C (36°F), and corresponds to a thermal compression of just 0.67dB https://www.stereophile.com/content/hot-stuff-loudspeaker-voice-coil-temperatures-page-2#R4eshWmRTxL... Its negligible. Most of my work is in the prosound world, and there the awareness of thermal compression is alive and well. If you put a $1k prosound speaker that does 5kw against a Magico, the prosound speaker would go louder but it wouldn't be as refined or high quality as the magico. If you were playing at such high levels in a home environment the main concern would be hearing damage rather than thermal compression. |
Trytone wrote: "Perhaps it is not that big a problem, Google "thermal compression" loudspeakers and there is a Stereophile article from 2006, complete with measurements." I remember that article and it dismissed thermal effects as being inconsequential. Since then I’ve had relevant conversations with two of the top researchers in the field, Earl Geddes and Floyd Toole. I asked Earl to look at the article and he told me what he found to be wrong with the methodology, the details of which I do not remember. But he felt the measurement method was fatally flawed. (In another conversation he specifically mentioned large voice coil diameter as a characteristic which minimizes thermal compression.) Later I had a conversation with Floyd Toole on the subject of "thermal modulation", which is rapid-onset (short time constant) thermal compression (as opposed to thermal compression based primarily on the loss of magnet strength as the magnet heats up over time). He said that it is a real phenomenon which has not been adequately studied, and went on to give the example of a three-way speaker he had tested whose midrange driver was compressing peaks on normal program material at normal home audio sound pressure levels by 7 dB! Finally, some years ago a recording engineer shared with me details of measurements that he had been recording for many years on many loudspeakers, looking specifically at how much they compressed a 20 dB peak. It was not unusual for a loudspeaker to compress a 20 dB peak by 3 or 4 dB, but some exhibited no compression (I don’t recall what SPLs he was using for his tests). He found a general correlation between efficiency and lack of compression on the peaks. There were some moderate-efficiency speakers that defied the trend, and these had unusually robust motors which presumably had very high thermal capacity. I’m not posting the details of what he told me here because he asked me to keep the details confidential, nor have I used some of the terminology that he developed, as he intends to write a paper based on his findings at some point. Most of my work is in the prosound world, and there the awareness of thermal compression is alive and well. If a prosound speaker is pushed hard, it compresses. My point being, thermal compression and thermal modulation (short-term thermal compression) are real things, but unfortunately that information is not widely known in the home audio world. It’s almost like a dirty little secret that speaker manufacturers don’t want to talk about. No manufacturer wants to admit that his megabuck exotic-diaphragm tweeters have thermal compression issues that a thirty dollar compression driver doesn’t. Duke |
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. |
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. |
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 |
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. |
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. |
@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 |
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. |
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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. |
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 |
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. |
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 |
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). |