Anyone ever heard a decent Icepower amp running newer Quad ESLs? That's something I would like to hear.
When I was auditioning for new speakers a few years back, the Quad ESL demo I got at a local dealer hit the bullseye for the sound I wanted, running of CJ amp gear, save for the punch in the bass not being up to snuff with the best I had heard. I tend to think as that as always the main problem with Quad ESLs at least from what I have read and heard with most any amp out there. The rest is more shades of grey amp to amp.
Increased emphasis for a SS amp versus tube in general sounds right to me. The FR with the SS may well be flatter as well, if not perfectly flat.
HEy but then there there is the old nasty odd order harmonics that muck with our ears due to NF issue with the SS amp for sure.
There may be no single right answer, at least on paper. Only our flawed ears know what they hear for sure always. |
Mapman, most Class D's I know off and some I have tested are greatly troubled by loads that go under 3-4ohms, and ESL's can dip to below 1ohm.
Cheers George |
GEorge,
I think you are right about that in general, from what I have read.
Still, not all Class D amps are created equal. I think I have read of some cases where they have worked well with very low impedances in some cases. It would be a concern, but you never know for sure till one tries. I'm wondering if anyone has? |
Al, as most here already know, is one of the more knowledgeable contributors on this website. I feel really fortunate that we often agree :)
Al did indeed get it right, as usual. The problem you often run into when trying to use solid state with ESLs is not enough bass and too much treble. When you look at the impedance curve of nearly any ESL, its easy to see why- it is common that the amplifier will be trying to make nearly 10x more power at 20KHz than it might be at 50Hz!
The thing is, as pointed out earlier, the ESL has a low impedance at high frequencies due to its capacitive nature and *not* because it is less efficient at that or any other frequency. It is the latter fact that is often understood by many, (apparently) including Georgelofi; this is why his comments can be safely ignored.
Of course there is not nearly as much energy at 20KHz, but the result is easily heard as brightness. That, coupled with the normal brightness associated with solid state amps (due to odd ordered harmonic distortion) is why such amps do not usually make the best choice for ESLs- even those meant for transistors. |
"That, coupled with the normal brightness associated with solid state amps'
That is a massive overgeneralization, and should be totally ignored.
"its easy to see why- it is common that the amplifier will be trying to make nearly 10x more power at 20KHz than it might be at 50Hz!"
Doesn't mean it's giving 10x the spl at those frequencies, it means it's staying linear and a have a flat frequency response into those load/s and frequencies.
If that were the case nearly every Solid State amp with good current ability would blow ESL's sky high at high frequencies, get real!
Cheers George |
Here is what is real... the feedback used in transistor amps is what keeps them from destroying the speakers. That same feedback is also one of the things that makes a transistor amp bright. It can do that to tube amps too, but tubes can run with less or even zero feedback and have good HF bandwidth even on ESLs.
It appears that George and I are at loggerheads. I have in the past had difficulty taking much George has posted with anything other than a grain of salt, as often (as we see in the post above) the *math gets ignored.*
He is the only one I know of to challenge a technical comment made by Al.
If we can see an ESL efficiency curve that shows that the efficiency of the speaker drops with the impedance curve, I would be willing to concede he had a point. But no such curve exists. What information that does exist suggests that any ESL has the same efficiency at 10KHz that is does at 50 or 100Hz.
There is also personal experience. Something like 80% of our MA-2 production over the last 23 years has been for Sound Lab installations. During that time, we have sold a lot of amps to customers with Quads, Acoustats, Audiostatic and King ESLs. In that time its been really obvious when we encounter an ESL that is designed for transistors- the highs are muted as George suggests. The thing is, that does not happen with *all* ESLs, only some, and there is a fix for that- the ZEROs as I mentioned earlier.
Also in this case I was careful to use the word 'associated' in my comment that he quoted (which excuses it from being a generalization, instead it is a statement taken from the experiences of many people).
Its my opinion that George is grinding an axe. |
Some cannot see the forest for the trees.
Martin Logan ESL Montise sterophile review, driven by Audioplax 80w tube monoblocks, also by ProLogue tube Premiums, and then by Simaudio Moon Evo 7's solid state.
Quote from the measurements by JA:
"The shape of the impedance trace will result in the Montis's top octaves shelving down when the speaker is driven by a tube amplifier having a high source impedance. This is why Robert Deutsch found that his Audiopax amplifier sounded too soft and lacking in definition."
Quote from the Robert Deutch review:
"The other tube amp I had on hand was the Audiopax Model 88 Mk.II. The Audiopax driving the Avantgarde Uno speakers is a "magical" combination: detailed and transparent to the source while minimizing the "electronic" artifacts of the reproduction process. The Audiopax-Montis marriage was not a happy one. Although the Model 88 Mk.II's rated output is 30Wpc—not that much less than the ProLogue Premium's 40Wpc—the Audiopax was dynamically on the subdued side even at moderate levels, and the sweetness and liquidity that had been so appealing with the Avantgardes now came across as too soft and lacking definition.
Next up was the Simaudio Moon Evolution W-7, a 150Wpc solid-state amp. The sound of the Montis driven by the Moon W-7 was vastly different from its sound with the PrimaLuna or the Audiopax. It now had dynamics in spades, evident as an ability to play much louder without strain, as well as more clearly present the ebb and flow of music at moderate levels. Bass was more extended and better controlled; the double-bass passages in Sylvia McNair's Sure Thing: The Jerome Kern Songbook (CD, Philips 442 129-2) were more distinct."
I have asked Roger Sanders to come to this disscusion he has cred both in ESL's and amplifiers to drive them with, so I hope he will respond. It's was posted here that he of course is biased towards his own S/S amps for esl's, but that was quickly edited out, why was that????
Cheers George |
Ralph- Save your keystrokes. |
I'll stand on my position that technical specs never tell the
whole story, and any given reasonable combo of gear, even with
electrostats, can win on any given day. Too many other
factors come into play. no substitute for listening and
hearing. Tube sound lovers will probably still like the tube
amp sound for the usual reasons and vice versa. Neither will
likely hold all the cards always. Like usual. Good sound is
shades of grey usually, not black and white. |
George, I happen to enjoy reading many of your posts in other threads. But I feel compelled to politely suggest that Ralph Karsten (Atmasphere) and Al (Almarg) are among the most respected A'gon members. Both are EE techies. And Ralph is the gent behind Atmasphere as in the "designer" and maybe the owner too.
In short, you're taking on some pretty heavy-duty guys. I suggest you back down and carefully re-read what Ralph and Al posted. I happened to think that what they wrote makes sense.
Ralph and Al, the discussion begs the question of how can one know whether an ESL was voiced to be driven by a tube versus SS amp. Obviously Sound Lab ESLs were designed to be tube friendly, ergo Ralph's comment that his amps have been coupled with Sound Lab ESLs for years. Is it the same old answer -- call the manufacturer and ask?? Or try to determine the type of amp that was used by the manufacturer to display the ESLs at shows??
Seems to me that what gets a bit dicey is the case where the ESL is coupled with a cone/dynamic speaker to cover LFs. Then we're back in the soup with "rock and roll" impedance curves.
Folks, let's try to remember this is a just a cool hobby and we're all friends.
Cheers,
Bruce |
Al, I don't mind; and, thanks. I think your comment "Which of those two kinds of amplifier/speaker interactions results in the most correct acoustic output from the speaker is a separate question, however." is particularly valuable and relates to another issue that you bring up, perspective.
As I said previously I tend to let those more technically astute explain these interactions, but after a lot of years in this hobby I am convinced that part of the reason that some of us "are at loggerheads" (besides ego and stubbornness) is that there are still aspects of sound and music and the perception of those that the technical doesn't fully explain. I would like to offer some thoughts about this from my perspective.
In my experience, and almost without exception, systems assembled with the stated goal of "linearity" don't sound the way that live music sounds. More times than not the result is sound that is tipped up in the highs and lean through the midrange compared to the sound of acoustic instruments. The argument that there is too much variability in the sound of live to establish a benchmark is nonsense; there is much more that is consistent than there is that is different. Most of music takes place in the midrange and most audiophile systems sound too lean in this range without enough fullness and image density particularly in the lower midrange. I can't remember how often I have heard comments about a system lacking bass when there really was no true bass content in the music and what the listener was missing was the appropriate fullness in the lower midrange and, perhaps, upper bass that gives music much of its power. "Linear" highs will often result in upper partial information that is not well integrated with the fundamental frequency and add excessive "presence" to the highs.
"Brightness" is an interesting descriptive term in that it is often confused with "texture". I have heard many systems (or recordings) that are described as "bright" which I would describe as harsh or grainy but definitely not bright. In fact I have heard systems that are dark and harsh (usually ss based) and others that are bright and overly smooth (usually tube based). Incorrect texture is what I hear oftentimes with ss amps driving electrostats and not necessarily excessive brightness (even when the sound is too lean, giving the illusion of brightness), and that is the main reason that tubes driving electrostats usually sound more natural to me: the fullness and image density of the midrange and the proper integration of harmonics with their fundamentals creating a texture and clarity that is much closer to the sound of live acoustic instruments even if, in absolute terms, the sound does not measure as "linear"; whatever that is. |
" The argument that there is too much variability in the sound of live to establish a benchmark is nonsense; there is much more that is consistent than there is that is different. "
Agree with Frogman on this. All live music has certain things in common. Patterns emerge and can be recognized with experience.
Also with the commonly accepted mindset that documented or measured technical specs and parameters are insufficient to tell the whole story regarding how well overall any playback system delivers the illusion of being real to individuals.
Its the twilight zone of home audio, that which cannot be explained fully based on scientifically established or otherwise known facts, that helps keep things interesting in that one never knows exactly what one will encounter until one encounters it. And each case will be just enough different most likely to still matter.
Just remember that the twilight zone is a prime feeding ground for charlatans and other purveyors of (intentional) disinformation as well. None of those in this discussion though, I would say. Misinformation (unintentional) is more prevalent as well. |
Ralph and Al, the discussion begs the question of how can one know whether an ESL was voiced to be driven by a tube versus SS amp. Obviously Sound Lab ESLs were designed to be tube friendly, ergo Ralph's comment that his amps have been coupled with Sound Lab ESLs for years. Is it the same old answer -- call the manufacturer and ask?? Or try to determine the type of amp that was used by the manufacturer to display the ESLs at shows?? That's easy. Most of the ESLs intended to be driven by transistors tend to have very low maximum impedances. For example MLs tend to be 4 ohms in the bass. When you figure that the typical ESL varies by 10:1 in impedance from the bottom octave to the top, that means that the MLs should be about 0.4 ohms at 20KHz, and a number of them are. However by use of a set of ZEROs you solve this problem, as I have mentioned before. Let's take the example of the ML and its 0.4 ohm impedance at 20KHz. The ZERO has taps that set up the amplifier load at 16 ohms, assuming that the speaker load is 4,3 or 2 ohms. If you are using the 4 ohm tap that 0.4 ohm load will look like 1.6 ohms. If the tube amp employs negative feedback it will have no trouble making this work with flat (linear) bandwidth. If the tube amp lacks feedback, you might have to use the 2 or 3 ohm tap, and it will still work quite well. So really what it comes down to is whether the tube amp makes enough raw power that might be suitable to drive the speaker. IME, the Accoustat is a good example. Some versions of the Accoustat, as mentioned earlier in this thread are high impedance, meaning a little OTL like our M-60s can drive them fine across the entire band. Other Accoustats have that dreaded low impedance and require the use of the ZEROs. A good friend of mine had a set of Accoustats like that, and he used our M-60s with a set of the autoformers. The amps made plenty of power- and the setup was in a room 17' by 24', and we never clipped the amps. The point here is that one must not confuse efficiency with the impedance. The ZERO is a problem-solver here- it allows almost any tube amp to effectively drive almost any ESL, provided the amp makes enough power in the first place. Rodman99999, Thanks, I think I see what you mean. |
Ralph and Al, the discussion begs the question of how can one know whether an ESL was voiced to be driven by a tube versus SS amp. Bruce, altho' you've directed the question to Ralph & Al, just my 2 cents: since ESL behave like (giant) capacitors which have impedance inversely proportional to freq, wouldn't it always be true that ESLs are almost always voiced with tube amps (not saying that you cannot or should not use a BJT-based power amp if you want to)? Barring those like Sanders Sound Lab ESLs where the impedance is deliberately kept low so as to use a s.s. power amp. |
I recieved an email from Rodger. (below in parentheses)
Roger Sanders ESL and amp guru is not one to get into heated debates on forums, this is why he has presented his white paper on the subject as simply as he knew how, so it can do the talking for those who can understand it.
So if this is wrong by anyone, a white paper should be done by the "one" who has the so called "knowledge" to oppose it. So he can also be then be also laid bare for all the audio community to view, like Roger has done with his white paper.
"Hi George,
I completely agree with your assessment of the tubes vs. transistors controversy among audiophiles.
Transistor amps are the only type that can produce linear frequency response and high output when driving ESLs. But getting audiophiles to understand and believe the technical reasons why this is so is difficult. You have your work cut out for you -- but I support you 100%.
I hope that posting my white paper will help some audiophiles gain a better understanding of amplifiers. I do not have the time to post on forums. And in any case, I am not interested in getting into arguments with audiophiles. So I will not be making any posts.
However, any interested individual may feel free to contact me directly if he has any questions."
Great listening,
-Roger"
Cheers George
|
Autoformers cost more than many speakers themselves. That's a factor to consider in the equation that can't be ignored. |
Ralph & Bruce & Mapman, thanks very much for the nice words.
Frogman, great post! I agree completely. Richness, body, and dimensionality are terms I find myself using frequently, I believe in the same sense as you are using the terms fullness and image density. And although I can't formulate a meaningful technical explanation, and I suspect that a good explanation would be a complex one involving a multitude of factors, my perception over the years has been that there is a tendency for those qualities to often be compromised in systems that are designed and assembled in a manner that results in flat frequency response being a leading priority.
Best regards,
-- Al |
"And although I can't formulate a meaningful technical explanation, and I suspect that a good explanation would be a complex one involving a multitude of factors, my perception over the years has been that there is a tendency for those qualities to often be compromised in systems that are designed and assembled in a manner that results in flat frequency response being a leading priority. " I'll offer up this wonderful resource again here to help with that. Audio ChartFactor in the ear sensitivity curves to help account for why flat may be technically correct but not sound best. |
Beside Roger Sander answer above in my last post which the non believers are conveniently blind to.
Here is and excerpt from the Stereo Times review of the difference when driving the Quad ELS2805 (while still hard to drive are easer than most ESL's) using tube then good solid state. Which also backs up everything Roger said in his White Paper and I've been saying and heard.
Stereo Times:
"The Quads are not as easy a load as one would be lead to believe by how good they sound with tube amplification. The Magtech further revealed the tube shortcomings (which I had already noticed) by expanding the peak performance range of the Quads. The “sweet region” grew to the limits of the speakers themselves. Meaning they suddenly didn’t have extended bass but what they did have was tighter and more refined. The top end was not more extended, just smoother and less brittle. The Magtech amplifier did not create new loudspeakers; it just let them be all that they could be."
Cheers George |
As the ear sensitivity chart at the link I referenced above shows, human hearing is far from flat over the 20-20kz frequency range normally associated with human hearing.
That means nothing that truly measures as flat will ever be heard as being flat. Far from it, in fact.
So technically flat or superior does NOT necessarily mean better sound that we hear as a result of being flat at the source.
So you can hear things that are flat as something otherwise or you might hear something that is not flat as being flat, or any shade of grey in between.
Fun stuff! I guess the wide range of things that might end up sounding good depending mostly on personal preference is what keeps Walmart from taking over the high end audio business.
I think I will go out on a limb and argue that the desirability of flat response at the source is a function of the variability of the music listened to. If its flat at the source, then a random sample that represents all music possible will overall sound better as a whole. If its not flat, results will be more biased towards certain types or patterns of music.
That's consistent with how I understand things and what I actually observe in practice in that I listen to and enjoy all kinds of music equally, though I know I could tweak things to sound better with certain kinds only if I wanted to.
I do that to some extent by running multiple systems in multiple rooms, each of which sound different, but my main (my reference) system in my main room is the one that I strive to perfect technically in the interest of best sound overall.
Sounds like one could create a technical reference quality system using the right tube amp with a particular set of ES speakers, but perhaps it will be more of a challenge to achieve reference quality in practice, as opposed to merely sounding really good. |
I used to own, the Acoustat 3 powered by a Conrad Johnson MV75A-1 -75 watt tube amp, no problems, beautiful sound.
I ran stacked Quad 57's with an AtmaSphere 30 watt stereo amp, beautiful sound ,no problems, also drove the same stacked pair with a 1961 Bell tube integrated(20 watts)great sound no problems.
Used to like my CLS 11Z speakers, but never found a tube amp that drove them as well as my mono Classe DR 6 amps.
Had a pair of Quad 63, that I never tried with a tube amp, but they did like the old Metner mono block power amps.
Now I am back to tubes and stats but it's the Acoustat X with it's own servo OTL tube amps.
Best combination so far of pairing a stat with tubes, but that should be as expected when each is made for the other.
Quad switched from tube amps to the current dumping solid state amps for any number of reasons.
Perhaps because tubes were felt to be obsolete, or because the newer 63 needed- demanded- more stability from an amp, or just because they wanted to, perhaps spurred on by the need to update their line.
I think,there are no rules set in stone,let common sense prevail and don't push either type of amp beyond it's limits. |
I am over 50, and I know my ears like most older ears do not even hear much above 12khz or so like they used to when I was a young audio "stud".
So getting flat response that works becomes a lot easier with age. Roll off of highs with ES speakers may in fact be a non-issue for most of us old audio farts. WHose to say a lot of younger ears that listen to the same are sensitive enough for it to matter either. |
Mapman, I'm not sure I get the gist of your point in relationship to the chart. |
Autoformers cost more than many speakers themselves. That's a factor to consider in the equation that can't be ignored. Have you checked the price on Zero autoformers? Even in the finished boxes I cannot see how your assertion could possibly be true. |
I am standing down. I read all the posts and respect the good intensions and credibility of all the folks who contributed to this OP.
My sense of the issue is purely academic. I'm still trying to get my arms around "simple" electrical compatibility concepts involving amps and conventional/cone speakers. Electrostats seem like a horse of a very differnt color.
I will say this. Any interest I had in trying ESLs is gone. It seems that amp/ESL compatibility is counter-intuitive. So I'll stick with what I have.
Btw, to the point about going with one's ears. I've been switching between my amp's 4 and 8 ohm output taps. For various technical reasons that I am not going to get into, I would have surmised that the 4 ohm taps would have been the preferred taps. But it just isn't always the case. At least that's what my ears tell me. So much for any notion of "faithful sound reproduction."
Well Stanely, "... that's another fine case" where changing speakers may be an exercise in futility.
Cheers and Happy Holidays.
Bruce |
The ear sensitivity chart shows why what measures as flat
response is not heard as flat response normally, It
illustrates why what measures as flat frequency response
may be perceived as bright.
A lot of mass produced SS gear feature things like filters,
loudness controls, and other tonal adjustments that don't
really work that well as a means of addressing this. Tube
amps in some cases may be better suited by their nature to
help compensate for how our ears hear.
Atmasphere always talks about how most amps do not address
how our ears actually work, which is a valid point. He
tends to focus on brightness from odd order harmonics due to
NF in particular, but I guess I'm suggesting there is more
to it perhaps than just that. |
Mapman, I would suggest to you that that reflects how the our hearing responds to a flat frequency response. The flat frequency response is a base line. Deviate from the baseline and our hearing would deviate accordingly. |
****Btw, to the point about going with one's ears. I've been switching between my amp's 4 and 8 ohm output taps. For various technical reasons that I am not going to get into, I would have surmised that the 4 ohm taps would have been the preferred taps. But it just isn't always the case. At least that's what my ears tell me. So much for any notion of "faithful sound reproduction." ****
That was PRECISELY my point. However, I consider what my ears tell me to be correct and the more "faithful sound reproduction"; and what I may have surmised due to theory as secondary in importance. As always, trust the ears; unless we smell smoke, of course :^) |
"I will say this. Any interest I had in trying ESLs is gone. It seems that amp/ESL compatibility is counter-intuitive. So I'll stick with what I have." Bifwynne
If you have not experienced a well done ESL system, you are missing out on the best! If you are located close enough to be practical (N. California), you are welcome to come hear mine. |
Theory helps one to play the game well, but ya still gotta play it.
Autoformers in finished boxes showed as costing over a grand. A barebones version would be less i suppose. Es speakers can be pricey, so its all relative i suppose. |
Bruce, I would not loose heart!
The issue that makes ESLs hard to sort out is that their impedance curve is related to a capacitor rather than drivers in a box.
But the allure is of course that ESLs are very fast and revealing, and if set up right, not painful for all that extra detail.
I agree that some things about ESLs can be counter-intuitive. For example many magazine articles have been written about how hard they are to drive, difficult load yada yada, but that really isn't the case.
OTLs, as you know, have a reputation about being load sensitive, but oddly have also been the preferred combination with ESLs going back to the 1950s. We have made that even more difficult for ourselves (since we make OTLs) by removing the feedback from our amplifiers, yet still they are able to drive ESLs quite well. So the 'difficult load' thing is really a common myth not supported in the field.
What *can* make an ESL hard to drive is when the manufacturer of the ESL decides he wants the speaker to be more transistor-friendly. MLs are a good example- 4 ohms in the bass, 0.5 ohms at 20KHz. Now there are many who would say that is a difficult load, but there are no crazy phase angles, so with proper matching (a set of ZEROs) such speakers become quite easy to drive with tubes since its more about impedance than anything else.
If you are contemplating going from a box speaker to an ESL, you may have to deal with things like having the speaker further into the room to make it play right. However the energy that comes off the back of the speaker is used by the human ear/brain system to get a better idea of where the sound is coming from; IOW to improve the soundstage imaging.
So I would not write off ESLs just because some things about them are counter-intuitive. If you have questions about whether a certain ESL will work with your ARCs, all you have to do is ask... I can tell you though that the combo will be good with Quad ESL57s and 63s, you will want the ZEROs with their later models, similarly with nearly all MLs. You will be able to drive Sound Labs directly no worries (however you will want the latest version of the backplate as it corrects a crossover error, making the speaker a lot better sounding and easier to drive), also King, Audiostatic and Accoustat. You will need a set of ZEROs with the Sanders ESLs as they are low impedance.
Also, your amp will be able to keep up with solid state amps, often with the ability to play with as much power as solid state amps of considerably higher power rating. This assumes the match is good (meaning that even if a set of ZEROs is needed, this will still be true). |
Es speakers are special and worth any special effort needed. Plus you have some good sidekicks here that can help to get them singing. |
Wouldnt two ohm or less impedance at high frequency be much easier for a ss amp in particular to deal with than if it were low? Way less power needed for high frequencybthan low. Or is it more complicated than that? |
^^ yes. But then you are dealing with 20 ohms or more in the bass. A 600-watt transistor amp just became a 250-watt amp.
This is why tubes work so well- the higher impedances are not as challenging. In the case of the Sound Labs, this means a 150-watt tube amp can keep up with a 600-watt transistor amp no worries. |
Autoformers in finished boxes showed as costing over a grand. A barebones version would be less i suppose. Es speakers can be pricey, so its all relative i suppose. Mapman, your original comment was Autoformers cost more than many speakers themselves. That's a factor to consider in the equation that can't be ignored. If you're talking about some of the smallest hybrid ESLs on the market, especially purchased used, you may have a point, but that is not 'many' compared to prices of ESLs currently manufactured and certainly not the majority no matter how you slice it. |
Yes Twb2, unless your prepared do your homework to get the right amp with ELS's, they will be a comprimise at the low impedance + difficult phase angles frequencies, as Roger Sanders ( in his White Paper http://sanderssoundsystems.com/technical-white-papers/172-tubes-vs-transistors ) and I have outlined a few times above, that many tend to be blind to.
Here are two more and there are many more on all brands of ESL's
Martin Colloms from HIFI Critic Report on the Quad ELS-2805:
"Amplifiers with more
than 0.6 ohms output impedance (which most tube amps can be) will cause shifts in tonal
balance, namely recessed over-sweet treble, and some
degree of lower midrange boom and bloom."
And also Keith Howard from HIFI News report on the Quad ESL-2912
" Impedance phase angle at low frequencies
is high enough to lower the EPDR (equivalent peak dissipation resistance)to a minimum ohm of 1.4ohm at 69Hz, but as the ESL- 2912's impedance will be level-dependent at LF the dips to 3ohm modulus at 7.5kHz and to 1.6ohm EPDR at 11.lkHz are more relevant and suggest a moderately difficult amplifier load."
Cheers George |
Over sweet treble and midrange bloom..... Sounds enticing! |
This thread has rekindled my interest in es speakers. |
Mapman: "Over sweet treble and midrange bloom"
You forgot to include the word "recessed" you guys are just too much.
Cheers George |
Bruce (Bifwynne), the lengthy response Ralph (Atmasphere) provided above to your last post provides, IMO, a nuanced, balanced, and technically sound perspective on the issue, derived obviously from extensive experience as well as technical expertise.
Here is another idea to consider, though: Supplement your dynamic speakers and the ARC amplifier with a set of Stax electrostatic headphones and a dedicated Stax headphone amplifier. That's what I do, and I really enjoy having the two different perspectives on what a given recording has to offer. As well as the fact that headphones eliminate (and facilitate assessment of) room issues, and allow me to listen at times when listening via speakers would conflict with my wife's activities.
Just a thought. Best,
-- Al |
Thanks Al.... Headphones is where my wife wants me to go. When my wife begs me to lower the gain, and then violates the serene sanctity of my blessed man-cave when she does so, I promise to turn the rig down, but turn it back up even higher when she leaves. LOL :)
Clearly Al, you are much more the gentleman than me because you switch over to headphones so as not to "conflict with [your] wife's activities." AL, ... I'm 19-year old child trapped in a 60-year old body -- just like a rat trapped in a steel cage.
I get the idea that negative phase angles coupled with low impedance attributes in a speaker's bass frequencies makes for a difficult to drive load. But good ole' George dropped a new term on us tech newbies, "EPDR (equivalent peak dissipation resistance)." Que'est ce se mon amies??? [What does it mean my friends?]
All the best guys. And ok, I'll put ESLs back on the speaker possibility list.
Regards,
Bruce
|
Bifwynne, I have to admit that on some level I agree, finding suitable amplifier compatibility for ESL's seems to be a bit daunting. While I've admired some of the qualities in ESL's in the past, certain aspects have kept me apart from them. I've yet to hear the mixing and matching of conventional drivers with them in the effort to negate the often heard deficiencies in bass response and macro dynamics done successfully. Still, they do seem to offer some superiority in other areas. In the past, I have attributed my perception of uneven frequency response in ESL's due to the challenge of properly coupling their somewhat unique dispersion patterns to the rooms they're placed in. Perhaps that was misplaced. Was the uneven frequency response I've experienced due to amplification issues? Though these challenges might be too much for me to overcome, I can still understand why some would be attracted to ESL's, despite these observations. Furthermore, I have still yet to hear the a couple of the most very favorably reviewed brands, so I keep an open mind to their ultimate capabilities. |
Frogman, your post of 12-5 here is one of the best of the kind I have seen on this site - thanks! |
"EPDR (equivalent peak dissipation resistance)." Que'est ce se mon amies??? [What does it mean my friends?]"
It is used by technical measurers like Keith Howard of HiFi news & Record Review, and John Atkinson of Stereophile when they review and then measure speakers. Because just a low impedance measurement does not reveal all that the amplifiers is seeing as a load.
The lowest EPDR (combind resistance and phase angle) of say the Wilson Alexia when measured by Keith Howard of HiFi News was a low impedance of 1.8ohms at 65hz and a lowest phase dip of negative -40degrees also at 65hz. These two measurements combined gave the Alexia a load to the amplifier of .9 of an ohm at 65hz. Big difference to just 1.8ohm resistive load.
You can read all about it here.
http://www.absolutesounds.com/pdf/main/press/WA%20Alexia%20HFN%200313-4web.pdf
Cheers George |
Thanks George, I read the article that uses the term EPDR. It appears to be a numerical factor that in some way combines and restates a speaker's impedance and phase angle attributes at a specific frequency as some sort of "impedance prime" equivalent.
Is there a formula that would enable one to make an EPDR calculation? What about cases involving inductive phase angles? How is EPDR computed in such cases? Are they hard on amps (tube or SS) like capacitive phase angles? Lastly, how significant is a low EPDR at a particular frequency when the frequency range where the EPDR is low may only be 10 or 20 Hz wide?? |
"increased emphasis of the upper treble"
Not right, "emphasis" is the wrong word it will give a flat response through the audible frequency range and cannot boost at these frequencies thus will not be effected.
And yes it will have more presence than an amp that is curtailed in these harder to drive areas because they cannot deliver the constant voltage because of limited current.
Just read and try to understand Roger Sanders WHITE PAPER on the subject.
http://sanderssoundsystems.com/technical-white-papers/172-tubes-vs-transistors
Cheers George |
George, your post just above quotes my use of the phrase "increased emphasis of the upper treble" for the second time in this thread, and both times you've omitted the words which immediately followed that phrase in the same sentence (see the second of my posts dated 12-4-13), which were "in comparison to nearly all tube amps."
That sentence says nothing whatsoever about whether the acoustic response having greater emphasis of the upper treble or the acoustic response having lesser emphasis of the upper treble will be more flat, or will be more musically correct (however that may be defined). As I indicated in the subsequent sentence, those are separate questions.
Numerous opinions relating to those separate questions have been expressed during the course of this thread by highly knowledgeable people, who in some cases drew careful, informed, and informative distinctions among different kinds of ESLs. As I see it further debate on those questions would amount to repetition of what has already been said, and would therefore be pointless.
I had read Mr. Sanders' paper, btw, and without getting into specifics (which would necessitate a very long post) I'll just say that it doesn't change any of my opinions, at least with regard to ESLs other than his own.
Regards,
-- Al
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My observations over the years has led me to believe that you either are a stat/planar lover or a cone lover.
Sometimes people shift sides over the years,for whatever reasons, but I have known more folks to stay in the planar/stat side of the speaker family once they've been exposed to a good set of planars/stats with proper amps SS or tube.
One of my friends bought back his old MonitorX stats after a decade or more of bouncing from one cone to the next.
Stats/planars have a certain sound and room interface that cones do not and cones can interact with a room in ways that planars cannot.
Our ears are the final arbitrator of what appeals to what we settle for,and neither speaker type is the best.
Nothing in audio is the best, there will always be something that was better or will be better or that can be made to be better than what we now consider the best.
So for me, what type of amp is best for an electrostat is something that only my ears can tell me.
It could be either, depends on the speaker and the rest of the gear, and the type of sound that I have groomed my ears to accept as pleasurable.
But my ears aren't the same as everyonelse, and what I consider good may sound like crap to someonelse.
We develope, over time and exposure to great sounding systems(seek them out and educate your ears)a sort of appetite for certain things.
Like going to restaurant.Somethings on the menu are appealing while other things are not.
I am not a sea food lover, but I know a lot of my friends are.
Some folks like cone speakers, some like stats or planars.
There also seems to be cookbook like recipes from audio gourmets who preach that cones like powerfull solid state amps that control the woofers with a high damping factor.
While some audiophiles drive 15 inch woofers with 2 watt SET and are quite happy with the results.
Lots of options on the menu, try them all until you find the ones that fit where you are NOW at this stage of your audio journey.
I've been thru several stages.
Each one was a place I could have stopped at, yet each was different from the one before and after it.
Did this make me a tortured lost soul, we so often read about?
You know the fellow who has to get off the merry go round, the fellow who has to downsize, the fellow who has found that this hobby is nothing but a sham and full of shills and snake oil, the fellow who believes that nothing good has been made in the last 40 years and that somewhere something went wrong and we lost our way, and nothing will get his mojo workin.
Nope.
That's not me.
I've found that there's so much good stuff out there, new and old, that putting together a system today that sounds great to my ears, is easier than it's ever been.
In spite of all the hand wringing we read about,you can mismatch an amp with a pair of speakers and be perfectly happy with the results.
I know a lot of folks who have done that.
And I have friends who are tortured souls,
They like the sound of that tube amp on their stats, but because someone says it's not politically correct, they have a change of heart,and set about looking for a solid state amp to correct the error of their ways.
But then the torture sets in because they like the sound of tubes,so on and on it goes.
A state of constant flux is a good thing.
Searching for that elusive absolute sound,in whatever way you want to define it, can be a fun thing or a totally frustrating one.
It depends a lot on your frame of mind.
Some folks constantly torture themselves flitting from one thing to the next searching for a nirvana that only exits in their mind or the mind of the audio guru of the day..Made ever so hard to achieve because one never knows what nirvana sounds like.It's always changing.
The reviewers are always finding something new that's the best.
When you accept that nothing is perfect it's just a state of mind, you can start to accept the flaws that all speakers and gear in this hobby have and learn to live with them.
I have learned to live with and accept the flaws in my stats and with the gear that drives them.
The positive things that I like about my sound out-weight the negatives.
I have heard better,but at far greater expense,and with flaws of their own.
So I've learned that nothing is perfect at any price point.
The fun thing for me is to find things that will make what I have sound even better, so I have gotten off the speaker, amp merry go round and stopped swapping components.
I've assembled some decent pieces and they work together.
I've heard some of those mega buck systems, and some are very good,but if money was no object, I couldn't decide on what I would buy.
They all sound great, and different at the same time. So which one is the best? The one to end with? At some point you have to settle for what you have and start to appreciate it flaws and all.
We can split hairs for the rest of this century about what is the best amplification for stats, or if Maggies are better than stats or if Apogees are the best etc.
In the end it doesn't matter,there will always be something better.And someone to tell you so.
So move on to it or tweak what you have to a place that you are happy with.
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Bifwynne
EPDR is not simple to work out you need Matlabs program that cost + the equipment to measure both parameters, unless you know the resistance and phase (which Stereophile do give) then all you need is the program.
Here is a link to the EPDR discussions on Stereophile with John Atkinson editor who's not using it yet and Keith Howard who does uses it from HiFi News & Record Review.
http://www.stereophile.com/content/epdr-wheres-formula-footnotes-1
Cheers George
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