|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
83.84.181.88
In Reply to: PS And Dr. Richard Heyser, in Audio. Try to tell us that *he's* all wrong. posted by clarkjohnsen on May 9, 2007 at 08:54:23:
In his Audio article Dr. Heyser makes reference to Hansen & Madsen, On awal phase detection. These authors have used an artificial signal, just like Wood. Even with that signal they pointed out that "improving the transfer characteristics of the [test] loudspeaker resulted in weakening the subjective perception of the change in the applied signal."However, that paper addresses phase, not polarity. They did find that polarity inversion was audible, using a test signal and an additional control unit which allowed to reverse polarity, but they did not specify whether or not it was audible on all speakers (the poorer and the better ones) used for the tests.
Dr. Heyser mentions the tests he has performed himself, but he does not specify what speakers he has used and what test signals.
You see what I mean?
Follow Ups:
can be done with a $300 receiver and the equivalent priced speakers.
I use a pair of Sonance Symphony 622C's. They are not time aligned, but sound pretty coherent and they are hooked up to a bottom of the line HK receiver.I believe speaker designs have deteriorated in that more (numerically) modern designs incorporate polarity inverted drivers. Older designs were much better aligned, at least in my experience.
I blame Harry Pearson of The Absolute Sound for this. He raved about the Proac Super Tablette which has the woofer inverted in polarity to the tweeter. 'Great Dimensionality and an unbelievably large soundstage' he gushed. That led all the manufacturers to adopt the woofer inverted design for smaller speakers. Monkey see, monkey do, or, in this case, Monkey hear, monkey do. Apparently HP can not hear polarity and phase issues.
Then some designer came up with inverting the midrange in a three way system, using the inverted frequency mid range to cancel out the overlap in the range of the adjacent drivers. A more even amplitude was claimed, which is fine if music was merely only sine waves (it ain't, folks!). Somehow it seemed to coincide with the rise of the PC and every one has been claiming 'computer designed' crossovers, as if just being available as a computer simulation makes it more correct.
It is true that an inverted midrange adds emphasis on the highs and the lows. Most novice listeners have difficulty in hearing the notes in the middle where most of music's fundamentals lie. A high frequency emphasis is heard as detail, and, of course, big bass is all about that visceral impact.
Ever notice that most speakers labeled as being analytical seem to suffer from an inverted driver? And then, I note the rise of the single driver speaker systems seem to coincide with the proliferation of the mixed polarity designs. There are many people who subconsciously, perhaps, know that something is wrong with many multi driver designs.
In a modern world where even singers use a synthesizer, and virtually no instrument is not electronically enhanced, few remember or even know what live unamplified instruments and singing sound like. But small changes in balance in the inverted designs can strike a certain chord in many listener's minds, leading to an endless chase for 'perfection'.
But you are most correct in that no one wants to point out speakers with phase, timing, or polarity errors. As you state, the simple tests results in Stereophile magazine point out many timing issues, but the magazine reviewers either choose not to point out problems or perhaps, sadly, they can not hear the problem. Or, perhaps the possible loss of ad revenue is more important than furthering the advance of audio.
It clears up a lot and answers a lot more.And if anyone needs further evidence that It's a dogma thing for our friend KlausR, read below.
For those who think that they hear absolute polarity, they should contemplate the following.Dan Shanefield, BAS speaker, vol. 17, no. 3 :
"once you see evidence of an additional factor which might really be causing the observed results, you should never ignore it in further studies. Instead, it must be carefully eliminated".
It has been shown (by Shanefield 1995 and Furindle 1976) that introducing distortion into the playback system makes polarity inversion more audible.
This reminds me of people claiming to hear the benefits of supertweeters. Then Kaoru and Shogo demonstrated in their AES aper that this is due to intermodulation distortion.So if it is possible that audibility inversion is audible because of good ole harmonic distortion, then that parameter should be investigated. But no.....
One answer to that problem is DSP. How many consumer speakers use DSP ?
Fortunately there are mags like Stereophile and Soundstage that provide meaurements. The ideal response curves are known from literature, such as JA's AES paper (available on Stereophile's website). One look at the graphs and you know the value of the speaker. But no....
Klaus
I have been subjected to 'tests' every time I go to CES. Unfamiliar material, unfamiliar equipment and have been asked to say correct or inverted after a minute or so of listening. I can hear polarity with a $300 receiver and speakers as well as in a high end preamp and amp combo in the $10K range with speakers in the matching price range. I'm sure their HD is quite low by anyone's measurement.You are searching for an easy out. The solutions are not quite so simple, but one would assume that you will have to start somewhere. I use real live listening sessions with real unamplified music as an absolute. You can measure away, buy expensive test instrumentation, but inevitably the final judge is the human ear (and I am NO golden ear!).
With all the technology which is currently available to us, I can not fathom why designers can not create a better speaker system which is phase and time correct and with adequate frequency response. The only answer I can see is lack of public interest (read $$$ here).
Maybe but without knowing a threshold you can't be sure. As far as I know such a threshold has never been determined nor have there been studies w.r.t how system distortion affects audibility of polarity inversion. Anyone serious about this issue would either conduct such studies himself or wait until such studies have beed conducted and solid data are available.A lot of advanced technology is available and only some use it. Speakers which are phase and time correct and which have adequate frequency response do exist, look at the ones I have. Given the fact that many audiophiles are willing to spend a lot money on speakers I frankly cannot understand why there's not more designers who implement technology that allows true improvement.
Stu
Klaus, PLEASE read up on the state of human hearing in: 'Models of Hearing' by Manfred R Schroeder, in the 'Proceedings of the IEEE', Vol. 63, NO. 9, September 1975.
Heyser would agree, if he were here.
30 years ago: He said something like, "That should satisfy the little ........" or somesuch, but in a more polite way. Then, I said, "But Richard, who reads the' Proceedings of the IEEE' but you and me?" I was right, unfortunately.
I knew that Klaus would not bother to read up on the subject!
Please tell me where is polarity mentioned, where are the listening tests w.r.t aubility of polarity inversion using musical excerpts described. Tell me because I cant find any.
Klaus
| ||||||||||||
|
This post is made possible by the generous support of people like you and our sponsors: