I was in Florida for a workshop circa 2000, and at one point got a ride from a woman who lived there. Pamela put on a CD in the car, which I instantly recognized as the Rachmaninoff 3rd piano concerto, a piece I know very well (listening, not playing!!). After the opening statement of the theme the heavy lifting began. Within a short time I was fairly shouting Who in h*ll is THIS??
Because I heard EVERY note of that piano part. I had studied the score in the days of my youth. Even Rachmaninoff, even the young Horowitz, had never played ALL those notes (and we hardly cared). Pam (who is a pianist) chuckled and handed me the jewel box: Arcadi Volodos.
I listened in rapt attention and amazement. I later read that I wasn't the only person to have this reaction, and someone wrote that he was the first pianist ever to play every note that Sergei wrote.
He also does quite well on other less-athletic material
I understand he practices constantly.
But we can pretend as if that distortions were desirable.
When I worked with Philharmonic band we once were called back from tourney to perform for pilots, because it was their professional holiday and they paid for it in advance. We quickly organized program for them, including some old good sons about pilots. One of such songs was long and boring, so we decided to modulate the last verse half tone above the pitch.
During concert everyone except bassist and singer forgot to modulate. Then keyboardist and guitarist went up, while bassist went back down. Then singer followed bassist, but somehow they got together and ended the song.
I sat in the middle of rows with my console, being red from a shame... There were mostly all professional musicians of that town in Kazakhstan who come to hear famous philharmonic band alive. After the concert when we discussed details one of them said, "Guys, you did something extraordinary good at that last verse of that song, something fresh and rythm-shaking!"
If best musicians of the town did not realize it was a sad mistake, who else did?
Resume: the difference between professional and amateur artists is, if professionals made mistake they continue as if nothing happened.
The same, as professional marketing departments highlight obvious flaws as if they are the best advantages of the design.
If we only knew which distortions are below audibility, and which are not. My continuous theme. Yes, speakers are the biggest problem. That's how I got sidetracked into amps, is that I build speakers that are not good enough yet.
Back to Spice lessons.
Hi,
That one is a lot like a russian doll or an onion.
Only after you stripped away one layer will you truely know the next one that needs stripping away (excluding members of the low church of the meter readers and double blinders that believe they already have all the answers, the wrong ones that is).
Do not try to bend the spoon — that's impossible.
Instead, only try to realize the truth: there is no spoon.
Ciao T
That one is a lot like a russian doll or an onion.
Only after you stripped away one layer will you truely know the next one that needs stripping away (excluding members of the low church of the meter readers and double blinders that believe they already have all the answers, the wrong ones that is).
Do not try to bend the spoon — that's impossible.
Instead, only try to realize the truth: there is no spoon.
Ciao T
You did surely read that i mentionned "measurements" ,
yet you re implying that i m talking of THD only..
You are too prompt to lead things where they dont belong
as such a move bring them where it suit your already made
intellectual strategy...
Of course there are other parameters like IMD although
there s quite a good correlation with THD levels , i.e ,
an amp that has low THD has generaly low IMD.
They are not meaningless , what was meaningless in such case
are the measurements protocols.
If a calculation yield a wrong result what is wrong is the computation
not the arithmetic operators....
There s no point in 1ppm THD but neither in speakers with 10% THD.
I would add that given the available technology , amps/preamps
with 0.1% THD are irrelevant if the audiophile status is to be claimed...
Although some would argue that it would need higher ratios
to deserve the said distinction in listening tests....
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Ultimately, the speaker can be seen as a mechanical device that produces low order harmonic distortion (2nds a nd 3rds mostly). We are used to it just the way we're used to full spectrum illumination - it doesn't change - we don't "see" it. Electronic devices are capable of producing lots of higher order harmonic distortion some of which (eg 7ths) our bodies just can't stand and we can feel it in very small concentrations just the way we can know somebody ran down a skunk even a couple miles away.
The speakers don't produce any IMD. A linear system cannot produce intermodulation.
But, if an amp that has 1% THD, probably has 10% IMD in certain conditions...
Because is easier to measure THD, and usually a device with lower THD has lower IMD also... THD of the audio chain (that can produce IMD) needs to be lower than the THD of the speakers (that will not produce IMD).
But, if an amp that has 1% THD, probably has 10% IMD in certain conditions...
Because is easier to measure THD, and usually a device with lower THD has lower IMD also... THD of the audio chain (that can produce IMD) needs to be lower than the THD of the speakers (that will not produce IMD).
Thank you for good news! Speaker is a linear system, it does not produce IMD! Such a relief! But how linear system produces non - linear distortions? I would be happy if it does not...
news to quite a number of people
aside form how worng the 1st part is by iteself the really fun part that others here are doublethinking themselves into knots over is that even a hypothetical "perfectly linear" piston driver does produce IMD from "Doppler effect"
even Rod Elliot figured it out eventually Doppler Distortion in loudspeakers
all it takes is to clearly measure is a cheap condenser mic and a classic bookself speaker with long throw 4-6" mid-woofer
Hi,
I am not implying that THD is the only one that matters or that you where talking only about THD, but I selected THD as one particular measurement to illustrate the fallacy of:
"There s indeed total correlation between measurements and sound quality."
In fact, the correlation between the kind of measurements currently routinely advanced as measures of quality or not for audio equipment not lack "total" correlation, they in fact lack ANY correlation with sound quality.
I could have tried the surrealist approach instead and have asked you to demonstrate how the length, width and height of the Amplifier offer "total correlation" with sound quality, as these too are measurements...
Instead I decided to be realist.
If for example I presented an Amplifier design with a THD of 3% at rated Power (H2 dominant, H3 over 12dB down on H2 and H4 another 12dB down, the rest in the noisefloor), a damping factor of 8, a -3dB Bandwidth of 10Hz - 40KHz (also power bandwidth) and a SNR of 80dB (@ 1W) and stated that the amplifier needed to be used with speakers that produce > 110dB/1m at the amplifiers rated power and show flat frequency response with the stated damping factor; there would be no end of contributors here who would chastigate such a design as having poor measured performance.
Yet non would produce any evidence that given the performance I outlined there would be any audible degradation of the music listening experience, nor would it be possible to do so, for the selected/recommended Amplifier/Speaker combination.
I do not understand what you are saying.
I threw the 10% number in the ring as each and every speaker I can think of will have this or higher levels of HD in the 20Hz - 20KHz bandwidth when driven at rated power and/or 108db/3m...
As for one PPM THD, I routinely read here ejaculations about the latests slightly tweaked generic circuit simulating at having a few PPB (Parts Per Billion) THD...
I would suggest that your number is both too low and too high. It is trivial to demonstrate that much higher THD than 0.1% is inaudible (even with pure tones) yet it is equally trivial to demonstrate that much lower THD than 0.1% is audible (and in fact highly objectionable).
The point is, THD is meaningless. It has no use in illustrating distortion audibility.
It correlates with no external factor that determines distortion audibility, it only correlates with itself and other similar distortion measurements (e.g. IMD).
It has been outdated for at least six decades.
Ciao T
I am not implying that THD is the only one that matters or that you where talking only about THD, but I selected THD as one particular measurement to illustrate the fallacy of:
"There s indeed total correlation between measurements and sound quality."
In fact, the correlation between the kind of measurements currently routinely advanced as measures of quality or not for audio equipment not lack "total" correlation, they in fact lack ANY correlation with sound quality.
I could have tried the surrealist approach instead and have asked you to demonstrate how the length, width and height of the Amplifier offer "total correlation" with sound quality, as these too are measurements...
Instead I decided to be realist.
If for example I presented an Amplifier design with a THD of 3% at rated Power (H2 dominant, H3 over 12dB down on H2 and H4 another 12dB down, the rest in the noisefloor), a damping factor of 8, a -3dB Bandwidth of 10Hz - 40KHz (also power bandwidth) and a SNR of 80dB (@ 1W) and stated that the amplifier needed to be used with speakers that produce > 110dB/1m at the amplifiers rated power and show flat frequency response with the stated damping factor; there would be no end of contributors here who would chastigate such a design as having poor measured performance.
Yet non would produce any evidence that given the performance I outlined there would be any audible degradation of the music listening experience, nor would it be possible to do so, for the selected/recommended Amplifier/Speaker combination.
I do not understand what you are saying.
I threw the 10% number in the ring as each and every speaker I can think of will have this or higher levels of HD in the 20Hz - 20KHz bandwidth when driven at rated power and/or 108db/3m...
As for one PPM THD, I routinely read here ejaculations about the latests slightly tweaked generic circuit simulating at having a few PPB (Parts Per Billion) THD...
I would suggest that your number is both too low and too high. It is trivial to demonstrate that much higher THD than 0.1% is inaudible (even with pure tones) yet it is equally trivial to demonstrate that much lower THD than 0.1% is audible (and in fact highly objectionable).
The point is, THD is meaningless. It has no use in illustrating distortion audibility.
It correlates with no external factor that determines distortion audibility, it only correlates with itself and other similar distortion measurements (e.g. IMD).
It has been outdated for at least six decades.
Ciao T
Hi,
Speakers produce IMD. Any non-linear system that produces harmonic distortion MUST produce correlated IMD. Speakers also produce PIM and even signal correlated Jitter...
In fact Mr. Klippel (famous for his speaker driver analyser) has a nice poster, which illustrates the various causes of HD and IMD in speaker drivers.
http://www.klippel.de/fileadmin/klippel/Files/Know_How/Literature/Papers/Klippel_Nonlinearity_Poster.pdf
As for quantification, Soundstage often posts HD measurements that are not very detailed, Voice Coil, Klang + Ton and Hobby HiFi routinely provide distortion measurements for all drivers they test (and the test many) and rest assured, most of these measurements do NOT look good...
iao Y
Speakers produce IMD. Any non-linear system that produces harmonic distortion MUST produce correlated IMD. Speakers also produce PIM and even signal correlated Jitter...
In fact Mr. Klippel (famous for his speaker driver analyser) has a nice poster, which illustrates the various causes of HD and IMD in speaker drivers.
http://www.klippel.de/fileadmin/klippel/Files/Know_How/Literature/Papers/Klippel_Nonlinearity_Poster.pdf
As for quantification, Soundstage often posts HD measurements that are not very detailed, Voice Coil, Klang + Ton and Hobby HiFi routinely provide distortion measurements for all drivers they test (and the test many) and rest assured, most of these measurements do NOT look good...
iao Y
Hi,
The notion was popularised (if not invented) by PWK...
One might also note that especially with 1950's grade speaker drivers and instrumentation the measurements would appear to support such a conclusion, if the speaker cone is made to have large excursion modulation effects on high frequencies are observed.
Here again we see that the empirical evidence stands the test of time, namely that large cone excursions create high levels of IMD, even if the theories formulated to explain the observed effect are now discredited.
Hurray for empicisim, scientific theories, oh pshaw...
Ciao T
The notion was popularised (if not invented) by PWK...
One might also note that especially with 1950's grade speaker drivers and instrumentation the measurements would appear to support such a conclusion, if the speaker cone is made to have large excursion modulation effects on high frequencies are observed.
Here again we see that the empirical evidence stands the test of time, namely that large cone excursions create high levels of IMD, even if the theories formulated to explain the observed effect are now discredited.
Hurray for empicisim, scientific theories, oh pshaw...
Ciao T
Don't be silly, Thorsten. I do not make absolute statements, I was very clear that to ME, that's how they sounded. Of course, their owners were deligthed with them, and that's just fine with me, it's only that I would not buy such stuff myself.
I should also add that in general, I don't much like the sound of zero overall feedback devices no matter what they are made with, because TO ME, they sound like unifinished products, as if something has been left out, sometimes unnaturally soft and rounded off, a bit like being out of absolute focus.
Again, their owners love them, and again, that's just fine with me, but not in my home.
I never did, and I never will try to convert such people to my way of thinking - some people love the priest, others prefer the priest's wife. To each his own.
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Ultimately, the speaker can be seen as a mechanical device that produces low order harmonic distortion (2nds a nd 3rds mostly). We are used to it just the way we're used to full spectrum illumination - it doesn't change - we don't "see" it. Electronic devices are capable of producing lots of higher order harmonic distortion some of which (eg 7ths) our bodies just can't stand and we can feel it in very small concentrations just the way we can know somebody ran down a skunk even a couple miles away.
Tweeters, metal ones in particular, are fully capable of producing 5ths and 7ths, IM and other nasty things.
Why single out tweeters?
ANY transducer WILL produce distortion, the question is only how much of it and where.
Anyone know of a distortionless microphone, cartridge, loudspeaker, headphone ...?
Or any other audio device, for that matter?
Including our ears, as for example anyone playing some of the Telemann recorder duets can discover (it's been suspected that Georg Phillip selected pitches sometime to intentionally produce a difference-frequency bass line).
Now there would be a signal processor --- a psychoacoustically Klippel-esque mirror filter/processor, to null the anticipated difference-frequency production
Brad
Sure but their 5ths and 7ths wind up some place i can't probably hear anyway. They sure can sometimes sound nasty, no doubt.
Gotta admit i was thinking of harmonics of low frequencies. If they come from upstream in the electronics, then you've got problems because of the energy component - more than 50% of energy in music is below 1000 Hz - because they show up in 700 Hz - 6kHz range. And we're really sensitive to sound from @2kHz to @ 5 -7 kHz.....
That's why I think you can hear surprisingly low amounts of distortion in an amplifier from a speaker that doesn't seem, by comparison to the amp, to have very good distortion figures.
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