Right now the highest efficiency speakers are for the most part, horns. Most horns have more reactive drivers due to the fact that they employ greater precision in their voice coil gaps. This extra reactive nature tends to mess with amplifiers of lower output impedance, particularly those that employ a loop negative feedback loop- thus the idea that horns can be 'shrill' or 'honky'. Horns also usually prefer an amplifier that makes constant power at all impedances (or at least *tries* to) rather than constant voltage. More info is at this link: http://www.atma-sphere.com/papers/paradigm_paper2.htmlSo now we see that the idea of 'all other things being equal' taking on additional meaning! IOW you must be comparing apples to apples, so the other speaker of lessor efficiency should also be a Power Paradigm device. Given this constraint, if the higher efficiency speaker indeed is as revealing, has the same bandwidth, images as well, etc., then yes, the greater efficiency will be an advantage- you don't need as much amplifier power to make it go. Since by definition we are talking about horns here, this is an advantage because the conversation makes no sense for the reasons I outlined if you don't also include tube amplifiers. The simple fact is that tube amplifier power is more expensive than transistor amplifier power. If you want realism (an orchestra can hit peaks of 115db to 120db), the ability to do this in a relaxed way without strain or harshness is then within grasp. It is simply not possible in most rooms if the speaker has low efficiency- too much is required of the amplifier! |
Are you saying that an amplifier will have to have fixed current to sound good on horns ... ? Weseixas, No. A constant power characteristic seems to be adequate, although Nelson Pass has shown that constant current amps work well for this as well. Your comment about transformers seems to be a red herring; if you are talking about an output transformer, they occur in amps that are constant voltage, constant power and constant current. IOW an output transformer has no bearing in this discussion. Unsound is correct in his surmise that I was referring to peak levels. Those who say that hearing damage is an issue at volumes like this are correct, however those same people should keep in mind that a real orchestra can reach these peaks with similar consequence. However an orchestra will sound real doing it, and most audio systems that are capable of that sound pressure don't, usually because of artifacts generated by the amplification. I was simply pointing out that a horn system would allow peaks like that to happen without said artifact, if you use the right amp. Unsound and I part ways in the matter of horns that can sound like real music: I have heard some that he has not and so have this opinion. Weseixas mentioned something about a planar magnetic and a very high powered amp doing the same sound pressure. Its true that it can, but you would not want to be in the same room due to the artifacts I alluded to earlier. Now if a magnetic planar had the same sort of efficiencies they might be worth a try. IOW this points directly to the issue of why efficiency is so important! In a nutshell, the only amps that are capable of sounding like real music don't make anywhere near 2000 watts- you need the efficiency. |
Unsound, I don't know. I can tell you this- one of them got "Best Sound at Show" at CES a few years ago, from Jonathan Valin of TAS. He followed up at the succeeding RMAF by saying that the new version of that same speaker (being played at that show) was the biggest improvement he had ever heard in any speaker!
I can add that I had an opinion similar to yours in the past- I thought all horns sucked. Boy was I wrong. Now I am of the opinion that horns, like all other speaker technologies, have unique pitfalls which can be avoided. If this is done they can be as musical or more musical (without coloration) as any of the best of competing speaker technologies.
Given your stance, I have to conclude that if you are being truthful about your position then you simply have yet to hear the speakers I'm talking about. |
Mapman, the simple fact is that any speaker that has high efficiency conforms to the Power Paradigm unless the designer went through extraordinary steps to prevent that.
All SETs and most zero-feedback amps are also on this paradigm. Yes, it is a 'minority' technology but in the opinions of the designers of such its the technology that offers the possibility of real music, as opposed to something that sounds like a stereo.
Now the Power Paradigm offers that possibility of being that much closer to the music. The idea is that the technology is totally committed to the rules of human hearing, which I think all of us can agree is the foundation of audio; without our ears we would not play with audio gear at all.
OTOH the Voltage Paradigm is all about looking good on paper (IOW pays little attention to human hearing rules), which our ears could give a damn about.
So going to higher efficiency is clearly an access to transformation in sound quality. Of course its better! |
Atmsphere, of course that is only your opinion, many if not most, have come to the opposite conclusion. Sorry, Unsound. What I have stated is simple fact; its not a matter of debate nor can I do anything to change it. Facts are like that. If you seriously think that what I stated my opinion then I advise you to study the theory and history of audio. Now it is true that the majority of the audio industry has chosen to use the Voltage Paradigm. If you look at history you will see why- high efficiency speakers are more expensive to build. Just follow the money. |
Timlub and Unsound, back in the 1950s the tube was the only game in town. Its no mystery that tube power is expensive- by the late 1950s the most powerful amps for home use made only about 60 watts per channel. Now it should not be a matter of proof (Unsound) but common knowledge that the closer tolerances used in high efficiency speakers results in greater reactivity (reverse EMF) from said driver. Timlub, I am including you in this post as the fact of the matter is that during the 1950s the higer efficiency speakers that existed out of necessity required greater precision to manufacture. However with the advent of the transistor inexpensive amplifier power became available. There were two things that were direct results: 1) amplifier manufacturers realized they could make more money, as the transistor amps cost less to produce, 50% less or more, yet they could charge at least 90% of what they did for tube amps of the same power. 2) speaker manufacturers realized a similar benefit; by reducing precision they lost efficiency, but the cost of the drivers fell by 90%. Its like I said, just follow the money. The advent of transistor amps and lower efficiency speakers was not about advancing the art (although the marketing certainly made it look that way) it was about *making money*. Unsound, if you want proof that I did not make up this idea of the Power Paradigm, look for a Fisher 55-A amplifier. Here's the Google search: http://www.google.com/search?hl=en&q=fisher+55-A+amplifierTake a look at the fifth hit (but look at the other links too). Its a Youtube video, but in the photo provided by Google, you see a control. The control is marked 'constant voltage' at one extreme 'constant power' in the middle and 'constant current' at the other extreme. Constant power is a zero feedback state in a higher output impedance amplifier. If I made it up, how come Fisher put that term on an amplifier made the same year I was born? The simple fact is the idea existed 55 years ago, and was the state of most tube amps, and speakers had to be designed to work with them since they were the only game in town. Such speakers like Altec, JBL, Klipsch and the like all have midrange and tweeter controls. Now most people *these days* think that those controls are there to allow the speaker to accommodate the room, but this is not true. The controls are there to accommodate the power response of the amplifier! Once you realize that fact, once I realized it, the reality of how things were done back then became more clear: it was the Power Paradigm. This is why I recommended you look at the history of audio. |
Unsound, Sorry, I don't see that post. Perhaps you could quote it? |
Unsound, is this the comment you want me to prove?: Now the Power Paradigm offers that possibility of being that much closer to the music. The idea is that the technology is totally committed to the rules of human hearing, which I think all of us can agree is the foundation of audio; without our ears we would not play with audio gear at all.
OTOH the Voltage Paradigm is all about looking good on paper (IOW pays little attention to human hearing rules), which our ears could give a damn about.
So going to higher efficiency is clearly an access to transformation in sound quality. Of course its better! The first paragraph seems to require little in the way of proof; I can guarantee that if we did not have ears we would not play with audio equipment. That part is simple enough. Paragraph two is simply taking on the idea that the main issue of the Voltage Paradigm is that it produces good numbers without those numbers having much to do with hearing rules. The proof is one that I know you already have seem me expound on in the past: The Voltage Paradigm looks for constant voltage response out of the amp. Another part of its platform is distortion as low as possible. In 99 44/100ths of cases, this requires loop negative feedback in the amp. Designers have known since the 1950s (see Norman Crowhurst- I'm not going to dig this up for you since it appears you need the history) that loop negative feedback increases odd ordered harmonic content. That violates the most important hearing rule- the one of how we detect sound pressure, which is done by listening and measuring the the amount of odd ordered harmonics. Obviously if these harmonics have been enhanced (distorted) even slightly, we can hear it and it will the difference between what we call 'good sound' and what we call music. The paragraph closes with the simple fact that our ears don't listen to numbers on paper. Your eyes are better suited to that task. The closing paragraph simply points out that the higher efficiency drivers are better suited to Power Paradigm technology, which from the previous paragraphs we saw pays closer attention to the effects of distortion upon the ear. That is why I used the word 'access' and 'transformation' as when this approach is used the results are instantly audible to anyone- it takes no golden ear to hear. Did we have the conversation about what Chaos Theory has to say about amplifiers with negative feedback? |
Hi Unsound, thanks for the greater specificity. You have not offered any proof that: "Now the Power Paradigm offers the possibility of being that much closer to the music." Here's how that one works: The Voltage Paradigm places its highest regard on flat frequency response. This is as close as the VP gets to obeying hearing rules. Now what we are talking about is the idea that the amp can make constant voltage with respect to load- that gets you flat frequency response when the amp is used with a speaker that has box or driver resonance as part of its impedance curve (in a nutshell). What this *ignores* is the fact that the human ear hears non-clipping harmonic distortion as frequency response variation. In fact the ear is just as sensitive to this if not more so then *actual* frequency variation. This is why two amps can measure identical bandwidth on the bench, but one can sound bright while the other does not- it has to do with distortion. So if the amp is *required* to use loop negative feedback either in pursuit of a low output impedance so it can have a constant voltage characteristic, or in pursuit of low distortion (the other 'looks nice on paper' spec) the result is that the amp will sound brighter since the 5th, 7th and 9th harmonics will be distorted due to the feedback. It happens that the ear uses these harmonics to measure how loud a sound is. So distortion in this regard of slight, barely measurable amounts is audible due to the fact that this is one of the ear's most sensitive aspects: our **survival** might depend on it!! IOW, the use of feedback violates a fundamental hearing rule- how we detect the volume of a sound. This is why I say that the VP is made to look good on paper, because it ignores this fundamental process of human hearing. Now if you can achieve low distortion and constant voltage without feedback, then you might have something. I know of only 2 amplifiers that can do that. I regard this as the cutting edge of technology and is the frontier where development can still yield results. If this obstacle can be overcome then I'm all for it. The way the Power Paradigm works is that it acknowledges that reducing the distortion can be more audible than flat frequency response, and that certain distortions are more important in this matter than others. IOW, it is placing a greater value on the hearing rules than the Voltage Paradigm is. To this end, loop feedback is eschewed due to the facts I previously explained. To maintain frequency response due to interactions with the speaker, different crossover techniques are used. To reduce overall distortion, non-feedback methods are employed, although depending on the designer a greater or lesser emphasis may exist regarding the presence of the lower orders (2nd, 3rd and 4th, BTW the 3rd is the only odd ordered harmonic that the ear does not hear as harshness- it regards this harmonic as musical like the 2nd and 4th). Personally I don't like the presence of the even ordered harmonics as they contribute to 'tubey sound' which I regard as a coloration (remember, the ear hears harmonic distortion as frequency response variation and this is an example). They can be eliminated by fully-balanced circuits. Or that: "OTOH the Voltage Paradigm is all about looking good on paper (IOW pays little attention to human hearing rules), which are ears could give a damn about." Now I did explain some of this already but in a nutshell the Power Paradigm holds as its highest ideal that the more the equipment is able to obey human hearing rules, the more its reproduction will sound like real music. The logic is obvious... The Voltage Paradigm by comparison holds the value of flat frequency response and overall lowest distortion as its ideals, regardless of the fact that in doing so a fundamental hearing rule is abused. That is why I say it cares more for appearance than sound. or that: "So going to higher efficiency is clearly an access to transformation in sound quality. Of course its better!" I already commented in other posts- this is the one about higher efficiency drivers being more reactive. Amps with feedback don't react well to this- this is one reason why horns sound shrill and honky when used with amps that employ loop feedback (again, in a nutshell). The point with this comment is that highly reactive drivers, if you want them to work right, are best used with an amplifier of little or no feedback. So the interaction between the amp and speaker is good, and the amp will not make the distortions that the ear finds to be the most objectionable (ideally- there are good and bad amps IMO regardless of what side of this debate they are on). That is the transformation- the access where the line between a good sounding stereo and a stereo that sounds like real music is crossed. IOW one has 'good' specs but the other is designed to obey human hearing rules. That difference is audible and is measurable too, once you know what to look for. Two side notes: 1) all headphones are Power Paradigm technology. 2) Its important to point out that with a lot of traditional horn speakers, the crossover will not work very well with a modern transistor amp. The reason is that the crossover rules for a Power Paradigm speaker have different assumptions than those of a Voltage Paradigm speaker, based on the way the amp behaves. The result is that a horn running with a transistor amp will often be playing out-of-band information at volume levels that the designer did not have in mind at all! |
The best is whatever you prefer. There is no intellectual way to establish actual factual superiority without measurements and these forums generally decline that pathway when it is presented. This is an emotional experience that cannot be assessed and evaluated by cold, unfeeling machines.
So -- we pirouette endlessly basking in polysyllabics and wielding cliches and formulae to no end whatsoever. Macrojack, it may interest you to know that those cold unfeeling machines have been used to measure the reactions in human brains to musical reproduction. This work was/is being done by Dr. Herbert Melcher, of Noble Prize fame. He found that as musical reproduction contains more and more artifacts that violate our human perceptual rules, that the processing of the music moves from the emotional centers (limbic system) of the brain to the cerebral cortex. This is why some systems evoke toe-tapping and others do not. Based on this work and research I have done as well, I do not agree *entirely* with what you stated in the quote. What the 'best' is has to do with how well the equipment is able to conform to human perceptual rules, both known and unknown. I thought you might find it interesting that Dr. Melcher has actually been getting objective numbers on the subjective experience :) |
Y'know, you probably *could* do it that way... lol :) |
Unsound, you've asked a lot of questions and it may take a bit to answer them all. I think first it needs to be understood that human hearing/perceptual rules are understood much better today than they were 20, 30 and 40 years ago. I may have suggested this before, but if not, the first thing to understand is how we perceive volume. One of the most important indicators to the human ear are the odd ordered harmonics, the 5th, 7th and 9th. Now that is easy to prove, all you need is a sine/square wave generator, an amplifier, a speaker, and a VU meter. You listen to the sine wave and set the VU to 0 VU. Then you switch to square and as best you can, set the speaker to what seems to be the same volume. You will find that to do so, the reading on the VU meter will be a good 20-25 db down. Other members of the 'gon have done this in the past, FWIW. Square waves are composed entirely of odd ordered harmonics. This simple test shows that we are more sensitive to them than we are the fundamental sine wave at over 100 times more energy. Now we have known since the 1950s that the addition of loop negative feedback enhances odd ordered distortions. I think I have pointed you to Norman Crowhurst's work on the subject in the past, if you have not read it, it would be a good idea to do so now because otherwise its like you missed a lesson in school. http://www.tubebooks.org/technical_books_online.htmscroll down a ways, there are 3 volumes available as a free download. Pay particular attention to the chapters on negative feedback and the methods he uses to chart the Nyquist diagrams! People have ascribed a lot to the sound of tubes and transistors; but I am here to say that the the very audible effects of 'bloom' that is a common audiophile term is really the effect of distortion. The 'brightness' of transistors is also an effect of distortion- in both cases this is easy enough to prove as you can put the amps on the bench and not measure any differences in frequency response, yet the effects can be heard on many speakers. The ear treats distortion as frequency response variation. Its that simple. So if you want the presentation to be neutral, the amp can't make distortion. Now if that were the case, then I would have no issue with the voltage paradigm as it would then insure flat frequency response. But the reality is that amps *do* make distortion, so the Voltage Paradigm will fail at that goal. Its my position that the effects of distortion are often more audible than frequency response variation. Anyone familiar with speaker design already knows how important the room is in any system, and how the speakers are often designed to work in a room. It is the room itself that guarantees that flat frequency response will not be realized, but our ear/brain system has a means of adjusting to the acoustics of the room. You might want to read some of the works of Dr. Earl Geddes on this one. So- I have given you some homework. BTW, don't discount Crowhurst simply because he was writing in the 1950s. A good deal of the technology you hear today is based on that foundation. |
I like most others here, don't have access to such equipment. If this data is so readily available, why isn't it routinely being published?
I might not completely understand what your suggesting, with re: to speakers and square waves, but to my knowledge the only readily available commercial speakers that can accurately reproduce square waves would not be considered "high efficiency". Unsound, To answer the immediate question, IMO its because this information is not very convenient. From the rest of this quote I feel that you *might* be missing my point... I mention this test because it can be done with almost any speaker, as the 0VU value is not particularly demanding. It is just a very simple demonstration of a principle of human perceptual rules, and one that is easily duplicated. IOW, its a proof. The point of it is that we use odd ordered harmonics to tell how loud a sound is. That's how our ear/brain system is wired and is true of all humans. So from my point of view, if our ability to tell how loud a sound is has to do with odd ordered harmonics (already present in the signal) then it is simple logic that we do everything we can to avoid distorting them since the ear is more sensitive to them then just about anything else. That of course is my conclusion and stand, but it is only simple logic. Reducing odd ordered harmonics is also why I mess around with tubes, as its a lot harder to do the same thing with transistors. That is a preference on my part. However I do not like many of the colorations of tubes (read: lush midrange associated with 2nd harmonic); I prefer things to be neutral. BTW its Norman Crowhurst, not Cromwell... If you look at his writings you find that he does not eschew negative feedback, but he also does point out its weaknesses. At one point he talks about how when feedback is added, the noise floor of the amplifier circuit then contains harmonics up to the 81st, plus inharmonic information related to intermodulations at the feedback node. In fact he points out that this *is* the noise floor of the amplifier. (BTW, Chaos Theory also predicts this very same phenomena. If you read his books, you saw the formula for feedback in an amplifier too...) Now I am not sure exactly when the perceptual rule known as 'masking' became understood, but this is the rule that made mp3s possible, and is the idea that louder sounds mask the presence of quieter sounds. The masking rule is why we cannot hear sounds below the harmonic noise floor created by feedback. Now it happens that if you have a noise floor consisting of hiss alone, that you can hear about 15-20 db into that noise floor (I suspect that this peculiar exception to the masking rule is the result of necessities of evolution, as wind and hiss are very similar). Whatever the reason, this does seem to be one explanation of why an amp without feedback can seem to have more low level detail than an amp with that employs feedback. BTW, I think we are getting a bit off-topic- is this a subject for a different thread? |
Unsound- certainly! On some level I agree with you, I just want to know at what point does pursuing this one consideration of the many, lose sight of the total goal. That is a matter left to the speaker designers! I can say though that they have been getting some impressive results in that regard in the last decade or so, so much that they won me over- before I got my current speakers I really did not think horns were 'high end'. Boy was I wrong. |
Unsound, what was the rest of that system like? |
