2 Channel Room Setup and Listening Tests

My comments are based on and interestingly enough documented in the Affordable Audio article that is the topic of this discussion, which may be found at :

http://www.affordableaudio.org/aa2010-09.pdf

In this article there are many paraphrases of statements that were allegedly made by people with whom who I have had long personal and professional relationships with. Even people who don't know those people as well as well find DK.s paraphrases to be "curious" . The phrase "highly disingenuous" comes to mind.

The process of documenting the inaccuracy of really strange paraphrases is often a lengthy process because really strange paraphrases are likely to be composed of things that the authors never anticipated, simply because they are so strange. Therefore, the strange and highly disingenuous paraphrases may not clearly rebutted by anything that can be quoted.

These were prefaced by a post (probably now removed by the cleanup) that basically said that the last time someone from AVS tried to teach us anything, he was banned. More to the point, there were no specific reasonable questions to address with tutorial answers. if DK thinks otherwise, let him post them here.

I answered the few questions that I could construe as being reasonable. Many questions (again hopefully edited out of existence) were like one I remember in particular from DK that faulted ABX for being difficult for home listeners to implement for testing loudspeakers. A follow up comment by an avid supporter stated that since ABX wasn't easy to implement at home for loudspeaker testing, this was proof that it was inherently useless and shouldn't be used for anything.

There was also a dismissal of any evidence that I couldn't quote from peer-reviewed papers, despite the numerous paraphrases from DK's AA article, some with references but many not even connected with any particular paper, that were accepted and even praised.

I pointed out some pretty serious flaws in DKs AA article, such as the fact that he claimed that ABX was criticized by name by papers that were written years and even decades before anything was ever published about the ABX methodology we developed and is used today for testing audio products. A key fact that DK seems to have missed and has not accepted that I can see, is that there are two significantly different listening test procedures that are called ABX. One developed long ago forf things like hearing tests and speech articulation. The ABX we we developed is different, partially because we wanted something for evaluating audio gear which is a different problem. For example, the old ABX generally is based on trials that involve only one instance of listening to a stimulus, while our ABX allows a virtually unlimited number number of instances.

DK apparently never studied the articles he cited thoroughly enough to figure out the important differences. So his article is based on demonizing a different listening test methodology than the one its author thought he was writing about..

Finally DK seems to think that ABX and other DBT listening test methodologies lack significant present day connection with audio, apparently unaware of the many JAES and AES convererence papers that are based on using it, and the importance of ABX and other DBT listening test methodologies(e.g. ABC/hr) for the development of perceptual coders. For example his only familiarity with ABC/hr up until lately seems to be Robert Harley's diatribes against it. Clearly, QK thinks that the sun rises and sets on RH's words of wisdom. ;-)

For example, DK says in his AA article:

http://www.affordableaudio.org/aa2010-09.pdf

"The application of blind and double-blind tests is thought by a small, but vocal, minority in the audio community to be
the supreme evaluation standard for detecting audible differences in audio systems. It is true that some types of audio
systems are well suited for blind and double-blind A/B or A/B/X type tests. A/B and A/B/X tests are useful in scenarios
when the two audio signals being compared are simple in nature. For example, telephone company engineers have
routinely used, and continue to use, A/B and A/B/X tests to evaluate improvements in voice circuit quality. [1] [2] [3] [4]
However, we must realize and understand that a test that is suitable for one type of audio system might not be suitable
for another. It is worth noting that the same company (the Bell Telephone System) that was responsible for the invention
and implementation of telephone service was the same company that was responsible for the invention and implementation
of home stereophonic audio systems. [5] [6] [7] It is even more interesting to note that while A/B and A/B/
X tests were found to be appropriate for evaluating voice quality improvements on bandwidth-limited telephone circuits,
subjective, non-blind listening tests based on careful listening, evaluator training and realistic home listening
conditions were the scientific standards for the evaluation of stereophonic audio systems."

In the above paragraph DK cites a number of articles that were written between 1934 and 1962 as proof that ABX for audio component testing shouldn't be used for stereo. He does this fully knowing that Clark introduced ABX for audio component testing in a 1982 JAES article since he later on cites Clark's JAES article. Clark's JAES paper would not have been accepted by the JAES review board as being something new and different if it were the same procedure that had been around since 1934. This issue actually came up during the vetting of Clark's paper for publication in the JAES and was explained at the time to the JAES review board's satisfaction. Among other things, DK appears to be accusing the AES review board of gross incompetence.

Just the tip of the iceburg, guys! ;-)

The bottom line is that as many of you know, I am very happy to engage sincere parties with even a hint of an open mind in exchanges of ideas about subjective listening methodologies. I unfortunately found these reasonable prerequisites missing in the instances that DK describes above.
Edited by arnyk - 7/8/12 at 11:15am

It is interesting that the actual means of transmission of signals down a transmission line is most like Scenario 2. In reality the beads (charge carriers) move relatively slowly, while the energy moves quite rapidly via wave motion.

You appear to equate goodness with bead motion along the transmission line, while in reality AC current accomplishes its goals primarily by means of wave action (up and down movements in your example).

The whole example strikes me as being strange and irrelevant. I can't believe that an EE prof can't come up with something less ambiguous and more fitting.

BTW DK you never did answer my questions about the transfer function for audio signals of power amplifiers that are being stimulated via voltage variations on the order of a few percent of line voltage via its power cord, where the response is taken off the loudspeaker terminals.
Edited by arnyk - 7/8/12 at 11:06am

Given the inherently flawed nature of most if not all SBTs, I am prone to believe that you may have done some of them that reinforced your beliefs. Where are the DBTs that would be a far more reliable (IOW adequately reliable) confirmation of the SBTs?

DK, just to clear things up (hopefully), my comment about the closed thread was my (apparently) lame attempt at some humor. I am very aware what occurred with the other thread. But with the overly serious responses that post received, I'm figuring my humor got lost in the translation.

Are your amps JC-1's? Great amps! I ran with a pair for many years (I am still using 2 A-21's for my center channel, and surrounds). I recently replaced the JC-1's with the DartZeel CTH-8550 Integrated, which I use in HT By-Pass Mode when using the Home Theater (unfortunately, I must combine my 2-channel and HT endeavors into the same room).
Edited by Rutgar - 7/8/12 at 12:09pm

Why is there a "chopping block" under your Parasound amps?

Are there any signficant differences between the above and http://www.affordableaudio.org/aa2010-09.pdf ?

The latter seems to totally word-for-word identical for the relevant parts of the thread you cited.

If there are significant differences, please list them completely.

Those adjustable shelves couldn't hold 64 pounds? So much for > $1000 A/V cabinet...

These felt pads for chair legs are about $5. They will let your amps slide in and out with ease.

So you have close to what, $15K maybe $20K driving your modded SDA's? I know that the SDA's are a legacy that Polk is no longer known for. But given a total budget I would love to place the CBT line array and some dual opposed sealed subs up against them and see what savings i could pocket personally.

I know Raife. That comment must be taken in the context of what is being replied to. Of course your system is relevant to the discussion, which transcends buywiring and other such disorder symptoms. What I'm getting at, is the heart of the matter, how you are "hearing" buywiring, directional AC fuses, Tiptoes, Tweek (which seems to be the earliest symptoms you have revealed, prior to your EE memorization apparently).
Like I said, wasn't bashing it, just found the "dual MTM" arrangement unusual. But judging from your mains, it seem that you are quite immune to source lobing effects (as opposed to say interchannel lobing, which is quite different perceptually).
Excellent. So, when you are performing your, umm, Evaluation Methodology for Consumer Audio Equipment and doing the diagram thing:

How are these "markers" being placed in the soundfield (pardon) within the room? Who is doing so and how? Can we assume the method is consistent for say, buywires or Tiptoes, etc? Are you locked in place or getting up to change fuses??
Which has what relevance to what extraordinary, need an entirely new Evaluation Methodology for Consumer Audio Equipment, type claim ami...excuse me, Raife?
The artificial stereo construct recorded/processed sound stage is realistic, to me. The room is fully treated.
Thank you. They are actually on loan from Cary, who were impressed enough at Axpona to send them to me, for free . Ditto for the David Belles stuff seen here. I have a constant rotation of equipment, including speakers of course, going all the time. Hopefully you consider the Power Modules stuff high end as well. Maybe even the stone head figure guy??
Btw, think you used Serinus as a Reference in your paper yes?
Yes! Of course, there was no sales volume previously, only custom work.
Well, SA is strictly part time, never to be primary income. I have a full time job. The majority of building is done off site, but I do have constant prototypes being tested...hence the prototypes.
Real shame, would have been interesting meeting and speaking, learning more about you methods and how AC is not only directional, but affects the "sound" of fuses dependent upon orientation!!!
That would have been a doozy. Not to mention seeing, excuse me, hearing, how far I needed to go with the 1812s to catch up to some 27(?) year old Polks in terms of fidelity! .
Tis also the reason for my late reply....and why I will be rather scarce here (if at all) for at least the next week.
But by all means, please don't let my absence derail your explanations of Evaluation Methodology for Consumer Audio Equipment..or red herrings and smokescreens about moi!

cheers,

AJ

No, I see a person who is either crazy or doesn't understand the basics of their field. Bizarre, to say the least. The "string theory" of electricity .
Now of course, this "theory" affects not only how a fuse is to be oriented..but sound?
Raife, where would one measure this in the soundfield, as you mention this has a profound impact. What measure in the soundwaves impinging upon the ear accounts for this?? Or is this a direct to brain TF "effect", bypassing the pinna entirely??

cheers,

AJ

Hi Diomania,

In all fairness to DK, lots of audio shelving products aren't designed for heavier amplifiers. The sliders are a good idea, although, I personally would never attach something like that to my gear.

So DK, you're claiming that your brain has nothing to do with your listening experiences?

Given all of the critical questions about your articles that you're sloughing, probably a good thing... ;-)

When are you going to admit that your AA article http://www.affordableaudio.org/aa2010-09.pdf flamed the wrong ABX test?

I'm at $40K and I'm only part way down the list!

Note that his speakers sum to somewhat under $5k. Here's a picture of them with the grille cloth off:



Anybody want to comment on the density of the comb filtering, particularly at the distances probable in DK's relatively short-coupled listening situation?
Edited by arnyk - 7/9/12 at 5:00am

I just stumbled upon this post and nearly fell out of my chair!

You seriously need to 'get out ' more.

You confuse the transmission of electrical current with the literal drift of electrons. Have you not heard of the EM field?

Under this imagined scenario I have several questions...

When (supposedly) all of the electrons flow from one end of the cable to another, must you turn the cable around? Can you tell this by an increase in resistance and a decrease in volume? Does the cable lose structural integrity at one end? or appear 'porous' and become less flexible at the other speaker end?

Not to mention that you must have quite a time to make coffee. etc. as you wait for the system to 'warm up' considering that the electron drift velocity is typically measured in meters per hour. The concept of dynamics in music is taking on a whole new meaning for me...

If folks are serious about this stuff, one really needs to spend a bit more time studying EM theory and less time reading marketing brochures.


And Arny, the driver arrangement makes the prospect of listening to a simple line array in the near field seem absolutely inviting! But hey. look a the bright side, they could be di-poles as well!

Which all goes to demonstrate just how little actual physics and how much aesthetics is actually involved in the hobby.

To say that I would have an approach that is a 180 degrees of this would be an understatement. So I didn't see a value placed on the SDA and I know using a traditional ball park ratio of electronics to speaker would put the value of the SDA's somewhere in the $120K range(?). At least its a general and loose guideline that I tend to go by.

My research shows that the SDA SRS 1.2TL max SRP was on the order of $3400 a pair back in 1991:.

http://polksda.com/list.shtml

The Spatial Computer Black Hole Room Resonance Damping System with 10" driver has a SRP of $1295 according to http://www.spatialcomputer.com/page9/page10/page10.html

I was unaware that a 10:1 ratio of electronics to speaker costs was considered to be a well-balanced investment.

Suffice it to say I think one could do better for $44K. I'm not knocking the SDA for what it was or currently is. But, the best way I can put this, I doubt they benefit greatly from $44K of backing electronics. I'm actually stunned and robbed of words.

The underlying, and unspoken, message that I get is that DK thinks that they are THAT good. I would like to hear them compared to my Statements sometime.

That's what I meant about adjustable shelves that come with this a/v cabinet. Unless it can't support 64 pounds. I would be disappointed if this +- $1200 cabinet can't. At least you want to put the felt pads under those chopping blocks so that they don't slide against the bottom panel of the cabinet. Hard surface sliding against hard surface ... ouch!

What about Salamander Triple A/V cabinet priced at +-$1200? Is it like that too? If you know of better products for sliding amps on hard surface, please feel free to share.

Are you really seriously looking to get into an argument about the man's choice of shelves?

You've made a claim: so I asked you a relevant question.

Then you've made an assertion: and I wanted to know why.
Now you have a problem with me asking for specifics about your post?