Recommended Read for the Everything-Sounds-The-Same-Club

[pctower]

Gee, I wonder why none of you objective scientists have never metioned this paper:

http://w3.mit.edu/cheever/www/cheever_thesis.pdf

[WmAx]

Gee, I wonder why none of you objective scientists have never metioned this paper:

http://w3.mit.edu/cheever/www/cheever_thesis.pdf

Please explain the relevance of this paper. No controlled tests seem to have been performed in order to confirm any of his suspicions of audibility. Heavy on the theory, lite on the substantiations.

As far as the "Everything-Sounds-The-Same" club insinuation, only a fool would believe that everything sounds the same. Certainly, the pathetic amplifier that meausred over 5% even ordered HD, sounded different. I would bet money that an ABX test would show audible differences compared to an amplifier with reasonable levels of THD. In addition, many tube amplifiers may have a mismatched audio output transformer resulting in a high output impedance vs. the dynamic loudspeaker load, specifically across the impedance non-linearities found at bass resonance(s) and crosoover filter points(fc). Result? Audible deviation of frequency response. Basicly, what you end up with is the same as if you added a hi-power capacity resistor of small value(1 ohm or so) in series with the loudspeakers and an amplifier with low output impedance.

-Chris

[Pat D]

[QUOTE=pctower]Gee, I wonder why none of you objective scientists have never metioned this paper:

http://w3.mit.edu/cheever/www/cheever_thesis.pdf[/QUOTE]

What kind of a club is that, Phil?

Are you implying that someone here thinks everything sounds the same? If so, shame on you.

I can't download the thesis on the computer in the library here in Florida, but as I recall he used single blind tests. In the past, you have asked what sort of blind tests might be acceptable in a college course, and there is one answer--these weren't even double blind. And yet you maintain that DBTs done by competent people are not scientifically valid, though I don't think you gave any reasons for that judgment.

I should also point out that his work does not break any new ground as to just noticeable differences, but simply maintains that the SS amplifier used (a Hafler?) could under some circumstances produce high order distortion products which could be audible under some circumstances. However, when I read it some time ago, I was not at all sure Cheever had eliminated other differences sufficiently to be sure he had identified what caused the audible difference.

[mtrycraft]

Gee, I wonder why none of you objective scientists have never metioned this paper:

http://w3.mit.edu/cheever/www/cheever_thesis.pdf

All sound the same? Prove this silly assertion.

Maybe this is the first exposure to this paper? Maybe it is an embarrasing paper to use as a reference? Maybe any number of reasons.

I presume you are impressed by this paper?

His premis is in stak contrast to what speaker researchers have demonstrated about measurements correlation to what you hear and prefer. Oh well.
I would have been more impressed with a better controlled listening test. Did he feed the piano to each amp and compared them to each other or to the live piano? If to each other, then you can maybe all sort of reasons.

[okiemax]

All sound the same? Prove this silly assertion.

Maybe this is the first exposure to this paper? Maybe it is an embarrasing paper to use as a reference? Maybe any number of reasons.

I presume you are impressed by this paper?

His premis is in stak contrast to what speaker researchers have demonstrated about measurements correlation to what you hear and prefer. Oh well.
I would have been more impressed with a better controlled listening test. Did he feed the piano to each amp and compared them to each other or to the live piano? If to each other, then you can maybe all sort of reasons.

It sounds like you are referring to a study that claimed listeners genrally agree on what is a good speaker. That's something I will try to remember the next time someone pulls up next to me at a stoplight with his 2000 -watt subwoofer pumping out street-shaking bass.

[markw]

As far as the "Everything-Sounds-The-Same" club insinuation, only a fool would believe that everything sounds the same.

Phil knows nobody ever said this. He just loves setting up straw man arguments to show how clever he thinks he is. ...and people wonder why I post lawyer jokes?

[E-Stat]

Gee, I wonder why none of you objective scientists have never metioned this paper:

http://w3.mit.edu/cheever/www/cheever_thesis.pdf

The two things I found interesting relate to the natural aural harmonic envelope of the ear and the detailed analysis of the unavoidable content of high order distortion of high feedback designs when fed instantaneous signal. As opposed to near worthless use of test tones for THD measurements.

rw

[mtrycraft]

Gee, I wonder why none of you objective scientists have never metioned this paper:

http://w3.mit.edu/cheever/www/cheever_thesis.pdf

He should try to publish it in JAES and get a real peer review?

[RobotCzar]

The two things I found interesting relate to the natural aural harmonic envelope of the ear and the detailed analysis of the unavoidable content of high order distortion of high feedback designs when fed instantaneous signal. As opposed to near worthless use of test tones for THD measurements.

rw

Why not say what it is that you found interesting about the "natural" arual harmonic envelope of the ear? How would we know that is without inserting electrical probes into ones brain (or nerves from the ear)? I think you would get plenty of agreement from rational listeners about what the harmonic envelope of the ear is (i.e., it is known scientificly) as long it it isn't high end opinion.

Don't you think it matters how much "high order" distortion there is? (THD tells you to sum of ALL distortion harmoonics). Higher harmonics are so very very very very low (when THD is very low) that they don't matter at all.

You keep repeating high end nonsense, like the idea of an "instantaneous" signal. A "worthless" THD test tone (sine wave) varies continuously (instaneously?) and is not worthless at all (as any signal, however complex, is simply the sum of a number of sine waves.

I, once again, recommend that you get information from some source other than high end pundits who are making it up as they go along.

[RobotCzar]

"There exists general agreement that the commonly accepted test and measurement protocols for audio frequency power amplifiers fail to correlate with the subjectively accessed devices sound quality."


There does not "exist" such general agreement. This paper is dead wrong (and offers no supporting evidence) in the very first statement it makes. There is no evidence that amps sound different when the "subjectively accessed" part is removed. (Does he reallymean subjectively assessed?)

Also, there is good evidence that measured factors like frequency response and distortion correlate very well to what we hear from amps that DO sound different (which makes sense as these factors are the only things that determine sound). Why make up lies?

This thing reads like a freshman paper, not a serious discussion of home audio issues.


Keep trying, PC....are you having difficultly getting more substantial evidence (like Mtry's ever growing list?)

[E-Stat]

Don't you think it matters how much "high order" distortion there is? (THD tells you to sum of ALL distortion harmoonics). Higher harmonics are so very very very very low (when THD is very low) that they don't matter at all.

Evidently, the concept of averaging distortion components over time escapes you. If you don't believe me, then listen for an extended period of time to an "ultra low distortion" (0.01%) preamp such as the Crown IC-150. I was searching the web to find the factory distortion specification and found this amusing comment that mirrors my experience:

http://www.visi.com/~asm/Gallery/Gal...fair_2003.html

THD specifications are worse than useless because there are some who actually believe they mean something useful when it comes to the reproduction of music.

rw

[pctower]

"There exists general agreement that the commonly accepted test and measurement protocols for audio frequency power amplifiers fail to correlate with the subjectively accessed devices sound quality."


There does not "exist" such general agreement. This paper is dead wrong (and offers no supporting evidence) in the very first statement it makes. There is no evidence that amps sound different when the "subjectively accessed" part is removed. (Does he reallymean subjectively assessed?)

Also, there is good evidence that measured factors like frequency response and distortion correlate very well to what we hear from amps that DO sound different (which makes sense as these factors are the only things that determine sound). Why make up lies?

This thing reads like a freshman paper, not a serious discussion of home audio issues.


Keep trying, PC....are you having difficultly getting more substantial evidence (like Mtry's ever growing list?)

Keep trying, PC....are you having difficultly getting more substantial evidence (like Mtry's ever growing list?)

I only look for "evidence" when I'm trying to prove something. When it comes to cables, I'm not one bit interested in proving anything.

Ever so often I see something like this paper that I have not seen referenced or discussed before. Since I have been under the assumption that discussion is the purpose of boards like this, I post it in an effort to move the discussion beyond the level of "yeasayer" vs. "naysayer".

But, candidly, so many people seem locked into that "matrix" (on both sides) that such efforts generally fall flat and are hardly worth the effort. I, myself, can't seem to escape from that "prison of the mind" because I seem to believe that in order to stimulate discussion or get it started I need to needle one side or the other when I post the reference. To the extent I contribute to the problem, I take responsibility for that.

[mtrycraft]

Evidently, the concept of averaging distortion components over time escapes you. If you don't believe me, then listen for an extended period of time to an "ultra low distortion" (0.01%) preamp such as the Crown IC-150. I was searching the web to find the factory distortion specification and found this amusing comment that mirrors my experience:

http://www.visi.com/~asm/Gallery/Gal...fair_2003.html

THD specifications are worse than useless because there are some who actually believe they mean something useful when it comes to the reproduction of music.

rw

What would they know? From th elooks of their equipment, no wonder they are so misguided. Besides, no mention of bias free demonstration of their opine.

[Monstrous Mike]

.... I seem to believe that in order to stimulate discussion or get it started I need to needle one side or the other ....

troll

v.,n. 1. [From the Usenet group alt.folklore.urban] To
utter a posting on Usenet designed to attract predictable
responses or flames; or, the post itself. Derives from the phrase
"trolling for newbies" which in turn comes from mainstream
"trolling", a style of fishing in which one trails bait through a
likely spot hoping for a bite. The well-constructed troll is a post
that induces lots of newbies and flamers to make themselves look
even more clueless than they already do, while subtly conveying to
the more savvy and experienced that it is in fact a deliberate
troll. If you don't fall for the joke, you get to be in on it. See
also YHBT. 2. An individual who chronically trolls in sense 1;
regularly posts specious arguments, flames or personal attacks to a
newsgroup, discussion list, or in email for no other purpose than to
annoy someone or disrupt a discussion. Trolls are recognizable by
the fact that the have no real interest in learning about the topic
at hand - they simply want to utter flame bait. Like the ugly
creatures they are named after, they exhibit no redeeming
characteristics, and as such, they are recognized as a lower form of
life on the net, as in, "Oh, ignore him, he's just a troll." 3.
[Berkeley] Computer lab monitor. A popular campus job for CS
students. Duties include helping newbies and ensuring that lab
policies are followed. Probably so-called because it involves
lurking in dark cavelike corners.

Some people claim that the troll (sense 1) is properly a narrower
category than flame bait, that a troll is categorized by containing
some assertion that is wrong but not overtly controversial. See
also Troll-O-Meter.

[mtrycraft]

Keep trying, PC....are you having difficultly getting more substantial evidence (like Mtry's ever growing list?)

I only look for "evidence" when I'm trying to prove something. When it comes to cables, I'm not one bit interested in proving anything.

Ever so often I see something like this paper that I have not seen referenced or discussed before. Since I have been under the assumption that discussion is the purpose of boards like this, I post it in an effort to move the discussion beyond the level of "yeasayer" vs. "naysayer".

But, candidly, so many people seem locked into that "matrix" (on both sides) that such efforts generally fall flat and are hardly worth the effort. I, myself, can't seem to escape from that "prison of the mind" because I seem to believe that in order to stimulate discussion or get it started I need to needle one side or the other when I post the reference. To the extent I contribute to the problem, I take responsibility for that.

I appreciate your link as I wasn't aware of it. I sent it on for comments. It has been discussed at other web sites. Not very convincing, Jung has been long discredited about his assumptions as well.

Just as the phase shift paper from Miami U that has statistics issues, this has issues as well.

[E-Stat]

What would they know? From th elooks of their equipment, no wonder they are so misguided. Besides, no mention of bias free demonstration of their opine.

Get back with us once you ask any one of your engineer buddies as to the quality of a circuit that uses a LM 301 opamp with copious amounts of negative feedback and electrolytic output capacitors.

My guess would be that in your "experience free" world, you have never had the distinct displeasure of hearing an ICCHH 150. Do tell though if you should ever decide to expand your horizons past your boom box. We're dying to hear your report.

rw

[jneutron]

I only look for "evidence" when I'm trying to prove something. When it comes to cables, I'm not one bit interested in proving anything.

Ever so often I see something like this paper that I have not seen referenced or discussed before. Since I have been under the assumption that discussion is the purpose of boards like this, I post it in an effort to move the discussion beyond the level of "yeasayer" vs. "naysayer".

But, candidly, so many people seem locked into that "matrix" (on both sides) that such efforts generally fall flat and are hardly worth the effort. I, myself, can't seem to escape from that "prison of the mind" because I seem to believe that in order to stimulate discussion or get it started I need to needle one side or the other when I post the reference. To the extent I contribute to the problem, I take responsibility for that.

Thank you, Phil.

John

[jneutron]

Was it you who mentioned a friend on Long Island, who could test some cables?

John

[E-Stat]

Was it you who mentioned a friend on Long Island, who could test some cables?

Yes it is. In fact I will be traveling to your lovely shores early next month and will ask. Harry does have some experience in these matters.

rw

[jneutron]

Yes it is. In fact I will be traveling to your lovely shores early next month and will ask. Harry does have some experience in these matters.
rw

Ah...good. A month may cut it..

I need to know what he uses, so I can find out the L-C characteristics of what he prefers.

I would then build cables that are equivalent, and bracket either side of them.

Ask him if he would like to contact me, and discuss the possibilities.

The guy that has my V1 cable is apparently sitting on his hands..

Cheers, John

[E-Stat]

I need to know what he uses, so I can find out the L-C characteristics of what he prefers.

Nordost Valhalla. For some reason the Nordost website is unavailable at present. I found these specifications in an Enjoy the Music review. Surely their ISP will get their act together and you can verify the specs. From the main page, you will see a multi-tabbed display with the many Nordost cables. The specs are found at the bottom of the Valhalla page.

Capacitance: 11.8pF/ft
Inductance: 0.096uH/ft
DC Resistance: 2.6ohms/1000ft/304M

Ask him if he would like to contact me, and discuss the possibilities.

That is my intent. I can't promise anything as he keeps a busy schedule.

rw

[jneutron]

The specs are found at the bottom of the Valhalla page.
Capacitance: 11.8pF/ft
Inductance: 0.096uH/ft
DC Resistance: 2.6ohms/1000ft/304M

Bummer...For my double braid design, that requires a dielectric coefficient of 1.09.

It will be easy enough to bracket the inductance significantly, but I don't yet have a useable dielectric that low...need more research...

But, it would be very nice see if he hears a diff with cables of varying LC's.

I'm testing out some other geometries, to see if I can go around that LC product limit.

Cheers, John

[jneutron]

Nordost Valhalla. Capacitance: 11.8pF/ft
Inductance: 0.096uH/ft
DC Resistance: 2.6ohms/1000ft/304M

Referred to the Nordost site..

I can't analyze the speaker wires of theirs yet, as I've developed no model. But I will state that the stated inductance seems rather low for the geometry...a gut feeling, but it'll be interesting to follow that..

However, for the interconnect, an interesting problem.

They state 55 nH, 22 pf, DC of 1.38.

But that equates to a DC of 1.17..

Assuming 22 pf and 1.38 correct, the inductance of their interconnect is 64 nH per foot.

If you include the 15 nH self inductance of the inner core, that is 70 nanohenries per foot, which is probably what happened...

They either provide calculated rf coax numbers for the inductance, as they probably can't accurately measure inductance that low....or the meter they used autoranged, and they used too high a frequency for the measurement..

Cheers, John

[skeptic]

This was an extremely disappointing paper. It was poorly written, had many mistakes, and seemed more like a diatribe rejecting accepted amplifier electrical performance standards without any real validity or objective tests to prove any correlation between what the writer claimed and his own proposals. In fact it wasn't really clear what he was proposing as a substitute aside from his own unsupportable specification but mostly it seemed like a mish-mash of current high end audiophile myths and legends. Negative feedback bad, no negative feedback good. Transistors Bad, tubes good. Push pull bad, class A good. I had a bad feeling about this as soon as he cited Stereophile magazine as a respected source. It went down hill from there. It seemed to me he was interested in justifying his own preferences and biases rather than proving any real superiority of one design philosophy over another. Of course I only made it through chapter one before I gave up. Still that was thirty odd pages.

One thing I did learn however. If I am ever confronted with a choice between a Hafler DH500 amplifier and a Carey amplifier, I won't thing twice before choosing the Hafler. As for any design where the engineer was so incompetent as to leave the choice of feedback to the end user, I'll pass on those. What this tells me is that there are a lot of people out there who don't have a clue as to how to properly incorporate negative feedback into an amplifier circuit. And it is hardly surprising because if you ever saw the equations you'd know they are a nightmare.