Debate Thread: Scott's Hi-res Audio Test - Page 35 - AVS Forum
Forum Jump: 
 734Likes
 
Thread Tools
post #1021 of 2920 Old 06-25-2014, 01:05 PM
Senior Member
 
koturban's Avatar
 
Join Date: Jan 2007
Posts: 427
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 185 Post(s)
Liked: 103
Quote:
Originally Posted by dB Cookster View Post
Thank you for preserving my contextual frame work, I will now provide you with the obvious answer.


"I do believe, if a major sampling (statically significant of a global mean) was organized, and administered, by appropriately accredited professions (i.e. not a lay person), etc., etc., etc. that the results would be worth looking at. However, in that no such endeavor has taken place, the existing efforts, are decidedly of little to no value, from a scientific perspective, which is not to suggest of absolutely no value."

"of little to no value from a scientific perspective" = the range of value in relationship to having scientific value.
"not to suggest of absolutely no value." = outside of science (i.e. in forums such as this)

I trust that these answers are sufficiently clarifying.
Nope. They are ambiguous.
koturban is offline  
Sponsored Links
Advertisement
 
post #1022 of 2920 Old 06-25-2014, 01:13 PM
 
Join Date: Jun 2014
Location: Canada
Posts: 39
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 29 Post(s)
Liked: 2
Quote:
Originally Posted by koturban View Post
Nope. They are ambiguous.

I have been told that rabbit holes are quite small, as a gentleman, I will leave this particular hole to you.


It's been interesting communication with you.


Cheers
dB Cookster is offline  
post #1023 of 2920 Old 06-25-2014, 01:21 PM
 
Join Date: Jun 2014
Location: Canada
Posts: 39
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 29 Post(s)
Liked: 2
Time to move along now...
dB Cookster is offline  
post #1024 of 2920 Old 06-25-2014, 01:33 PM
AVS Special Member
 
Frank Derks's Avatar
 
Join Date: Jul 2002
Location: Region A,B,C
Posts: 1,913
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 110 Post(s)
Liked: 89
Quote:
Originally Posted by dB Cookster View Post
The Doppler Effect is a 'product' of a root causation(s), it is not the cause of all inherent non-linarites, as your wording suggest: "due to the Doppler effect."


John is correct, in that truly linear devices, mechanical or otherwise, will not intrinsically produce a Doppler product.


+1 for the UK schools!

Nope,


He mentioned intermodulation not Doppler.
Frank Derks is online now  
post #1025 of 2920 Old 06-25-2014, 01:47 PM
Senior Member
 
stereoeditor's Avatar
 
Join Date: Feb 2010
Posts: 343
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 140 Post(s)
Liked: 39
Quote:
Originally Posted by Frank Derks View Post
[John Atkinson] mentioned intermodulation not Doppler.
I mentioned intermodulation because in the case of the Klipsch paper introduced to the thread by Arny Krueger, the spectral analysis clearly shows intermodulation distortion, not Doppler distortion, due to the drive-units being driven by the high-level 50Hz tone beyond their linear excursion limit. Doppler distortion can be negligible in modern multiway speakers, I feel.

John Atkinson
Editor, Stereophile
stereoeditor is offline  
post #1026 of 2920 Old 06-25-2014, 03:26 PM
 
Join Date: Jun 2014
Location: Canada
Posts: 39
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 29 Post(s)
Liked: 2
Quote:
Originally Posted by Frank Derks View Post
Nope,


He mentioned intermodulation not Doppler.
Actually, here's the full context:


Quote:
Originally Posted by RayDunzl
Doppler distortion would occur in any object vibrating with two or more fundamentals.
Not in a linear system. You only get intermodulation if there is a non-linearity.

John Atkinson
Editor, Stereophile


John clearly states that Doppler distortions don't occur in linear systems. Which is correct, as this effect is the product of factors, which are not present within a linear device. He further and correctly stated that in such a setting that IMD only would result, from the presence of non-linearity's... He is clearly correcting Ray's assertion that "any object vibrating with two or more fundamentals." I believe that John has since explained his usage of adjective, intermodulation.


Anryk later challenged John, but in doing so, it seems that he mentally inverted the relationships, momentarily thinking that a Doppler product was in fact a root causation stating: "A really surprising post from someone who should know that there is an inherent non-linearity in a moving diaphragm due to the Doppler effect." This statement has little to do with Johns context (Linear device) but regardless of this fact, as a standalone statement, is not true; not even in the broadest sense. A sensible broad statement would have been one that suggested that the inherent non-linearity's within loudspeakers have their roots in the frequency and amplitude dependent, electrical and mechanical impedance shifts, which are further, and varyingly exacerbated, by the addition of passive crossover components, enclosures, etc.. From this depiction, a more concrete understanding would have been made available, to build upon, or to reverse engineer; however, it still would have remained out of context, making it ultimately, an unnecessary comment.


For me, I wasn't defending John, as he's capable of doing so himself. I was correcting a technical error in Arnyk's response, regardless of its relevance to Johns context.


I suspect that these are merely clumsy mistakes, that statistically must come about, from time-to-time, as a result of being human.
dB Cookster is offline  
post #1027 of 2920 Old 06-25-2014, 03:38 PM
 
arnyk's Avatar
 
Join Date: Oct 2002
Location: Grosse Pointe Woods, MI
Posts: 14,530
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 851 Post(s)
Liked: 1205
Quote:
Originally Posted by dB Cookster View Post
I believe that my comments are all encompassing, as such; any audio ABX tests that one can place their hands on, will suffice.
Global demonization if there ever was any.

The author has no idea of the details of all audio ABX tests simply because so many ABX tests have been done in private that nobody know any such thing.

Amir has been complaining that I have not documented many of the ABX tests that I've done. I am therefore looking to this author's detailed deconstruction any of them. After all, he's the one that used the words "all encompassing".

Last edited by arnyk; 06-25-2014 at 03:42 PM.
arnyk is offline  
post #1028 of 2920 Old 06-25-2014, 03:39 PM
Senior Member
 
hevi's Avatar
 
Join Date: Jan 2007
Posts: 365
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 33 Post(s)
Liked: 48
Quote:
Originally Posted by dB Cookster View Post
Quote:
Originally Posted by amirm View Post
Quote:

Let me quote International Telecommunication Union (ITU) document that is the bible of testing for small impairments in BS1116:

"It should be understood that the topics of experimental design, experimental execution, and statistical analysis are complex, and that only the most general guidelines can be given in a Recommendation such as this. It is recommended that professionals with expertise in experimental design and statistics should be consulted or brought in at the beginning of the planning for the listening test."

This is a 30 page document describing many aspects of proper controlled listening tests and it still says that it is just scratching the surface and that qualified people need to be consulted before running head long into such testing.

"3.1 Expert listeners
It is important that data from listening tests assessing small impairments in audio systems should come exclusively from
subjects who have expertise in detecting these small impairments. The higher the quality reached by the systems to be
tested, the more important it is to have expert listeners."

"The outcome of subjective tests of sound systems with small impairments utilizing a selected group of listeners is not
primarily intended for extrapolation to the general public. Normally the aim is to investigate whether a group of expert
listeners, under certain conditions, are able to perceive relatively subtle degradations but also to produce a quantitative
estimate of the introduced impairments."

"3.2.1 Pre-screening of subjects
Pre-screening procedures, include methods such as audiometric tests, selection of subjects based on their previous
experience and performance in previous tests and elimination of subjects based on a statistical analysis of pre-tests. The
training procedure might be used as a tool for pre-screening.

The major argument for introducing a pre-screening technique is to increase the efficiency of the listening test. This must
however be balanced against the risk of limiting the relevance of the result too much."

"3.2.2 Post-screening of subjects
Post-screening methods can be roughly separated into at least two classes; one is based on inconsistencies compared
with the mean result and another relies on the ability of the subject to make correct identifications."

"4.1 Familiarization or training phase

Prior to formal grading, subjects must be allowed to become thoroughly familiar with the test facilities, the test
environment, the grading process, the grading scales and the methods of their use. Subjects should also become
thoroughly familiar with the artefacts under study. For the most sensitive tests they should be exposed to all the material
they will be grading later in the formal grading sessions. During familiarization or training, subjects should be preferably
together in groups (say, consisting of three subjects), so that they can interact freely and discuss the artefacts they detect
with each other."
dB Cookster-


These excerpts are sufficient (without additional commentary) for use in disqualifying all past, present and most probably all future ABX listening tests, from being viewed as a scientifically objective, measurement metric, of such subtleties! I am surprised, to have discovered that they have been given such weight, within many of these forums. A curious occurrence, for certain!

I do not agree with your disqualification of ABX listening tests in general -DBT is a good practise, and the criteria how you select your test subjects is in my mind another dimension of the "testing problem". It is really a matter of what you want to study (now speaking generally an not specifically about audio listening tests). In many cases you want to study the "general public", to find different sensory thresholds for the broad public. In other studies you may want to find the absolute limit of what is possible to detect (and of course, all combinations in between).

With that said, the latter par of the blue in your quote pretty much sums up how the Swedish AES goes about its testing. They use a small group of listeners (3-4 each session) where the majority of the group have proven to be very good at detecting colorations under blind conditions in the past, they do an open "training session" where they discuss what coloration they think they hear, and the they do a DBT A/B session.


Their test results are somewhat different from the conclusions arnyk et. al. have come to. They (Swedish AES) often find statistically significant differences between DUTs under DBT conditions.

Their latest test of two DACs (Denon 300USB and Cambridge Audio DACMagic plus), for example, the DACMagic was detected 10 out of 10 times by two out of three listeners while the third listener answered pretty much randomly. The Denon was also detected (one of the listeners that had 10/10 on the DACMagic had 9/10 on the Denon). The comparison was not against each other, but against a reference CD-plyer that has yet to be detected in a DBT.


Last edited by hevi; 06-25-2014 at 03:48 PM.
hevi is offline  
post #1029 of 2920 Old 06-25-2014, 03:47 PM
 
arnyk's Avatar
 
Join Date: Oct 2002
Location: Grosse Pointe Woods, MI
Posts: 14,530
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 851 Post(s)
Liked: 1205
Quote:
Originally Posted by stereoeditor View Post
I mentioned intermodulation because in the case of the Klipsch paper introduced to the thread by Arny Krueger, the spectral analysis clearly shows intermodulation distortion, not Doppler distortion, due to the drive-units being driven by the high-level 50Hz tone beyond their linear excursion limit. Doppler distortion can be negligible in modern multiway speakers, I feel.
Amir correctly identified the drive units in question, even posted a picture of them - they were Bose 901 which as we both know is not a multiway speaker.

For the benefit of the other readers, the Bose 901 is a full-range crossoverless 1-way loudspeaker. It has multiple drivers but they are all connected in series-parallel and receive their signal from a common source.

Nice try, but no cigar!
arnyk is offline  
post #1030 of 2920 Old 06-25-2014, 03:51 PM
 
arnyk's Avatar
 
Join Date: Oct 2002
Location: Grosse Pointe Woods, MI
Posts: 14,530
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 851 Post(s)
Liked: 1205
Quote:
Originally Posted by hevi View Post
Their test results are somewhat different from the conclusions arnyk et. al. have come to. They (Swedish AES) often find statistically significant differences between DUTs under DBT conditions.

Their latest test of two DACs (Denon 300USB and Cambridge Audio DACMagic plus), for example, the DACMagic was detected 10 out of 10 times by two out of three listeners while the third listener answered pretty much randomly. The Denon was also detected (one of the listeners that had 10/10 on the DACMagic had 9/10 on the Denon). The comparison was not against each other, but against a reference CD-plyer that has yet to be detected in a DBT.
Have we ever settled whether the Swedish group's tests are really DBTs?

Could you please point us at some good documentation for any of their efforts that would be relevant to this discusion?
arnyk is offline  
post #1031 of 2920 Old 06-25-2014, 04:05 PM
 
arnyk's Avatar
 
Join Date: Oct 2002
Location: Grosse Pointe Woods, MI
Posts: 14,530
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 851 Post(s)
Liked: 1205
Quote:
Originally Posted by dB Cookster View Post
The Doppler Effect is a 'product' of a root causation(s), it is not the cause of all inherent non-linarites(sic), as your wording suggest: "due to the Doppler effect."


John is correct, in that truly linear devices, mechanical or otherwise, will not intrinsically produce a Doppler product.
Your posts often have a fatal characteristic - they lack an accurate quote of the statement that you purport to be responding to. You've done this to me enough times that it is not likely to be just a careless accident.

I never said that the Doppler effect is the cause of all nonlinearities, inherent or not.

Therefore you are arguing with yourself. Enjoy!
arnyk is offline  
post #1032 of 2920 Old 06-25-2014, 04:08 PM
Senior Member
 
hevi's Avatar
 
Join Date: Jan 2007
Posts: 365
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 33 Post(s)
Liked: 48
Quote:
Originally Posted by arnyk View Post
Have we ever settled whether the Swedish group's tests are really DBTs?

Yes. They have not always done rigid DBTs, but since several years they do, and they still detect DUTs.


Quote:
Originally Posted by arnyk View Post
Could you please point us at some good documentation for any of their efforts that would be relevant to this discusion?

I am sorry to say, if you're not comfortable with my sketchy summarisations of their efforts, you need to pay the membership fee and learn Swedish, and then you're good to go.


Last edited by hevi; 06-25-2014 at 04:46 PM.
hevi is offline  
post #1033 of 2920 Old 06-25-2014, 04:37 PM
Senior Member
 
urapnes1's Avatar
 
Join Date: Mar 2007
Posts: 307
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 43 Post(s)
Liked: 36
Quote:
Originally Posted by arnyk View Post
Amir correctly identified the drive units in question, even posted a picture of them - they were Bose 901 which as we both know is not a multiway speaker.

For the benefit of the other readers, the Bose 901 is a full-range crossoverless 1-way loudspeaker. It has multiple drivers but they are all connected in series-parallel and receive their signal from a common source.

Nice try, but no cigar!
In case anyone cares, somewhere in the lifecycle of the 901 the wiring scheme was changed at least twice. From a combination of series and parallel drivers to just series. There was an interim model which had the ability to split the speaker up electrically:

Here is a quick bit that I found on the Series III

"The spacial effect and control on the original Bose receiver depended upon the Series III speaker (can't remember if it carried over to the Series IV). Effectively what you had was a receiver with 4 amps. 2 of these amps drove one speaker and the other 2 amps drove the other speaker.

How did this work? Well, there were 3 terminals on the bottom of the Series III speakers. The speakers were wired so that the inner 4 drivers (referenced to as you would face the 901) could be hooked up separately while the outer 4 drivers and the front-facing driver were wired to the other amp on that side. So, you ran 3 wires to the each of the speakers.

Now, in the receiver, the spatial control would route the stereo signal to L and R as in any other receiver. When you started moving the spatial control, the opposite signal would be routed to the speaker's inner 4 drivers. That is, on the left hand speaker, the inner 4 drivers would start to have part of the R signal playing through it. Same on the R where the L signal would start appearing on the inner 4 drivers. Since these inner 4 drivers faced toward the middle, the effect was to fill in center with an opposite channel thus allowing you to control how much blend there was during playback.

The fact was, however, that the whole thing was far too complicated for most folks and required additional understanding during hookup. The whole Spatial Control technique died off quickly and the magic 3rd connector on the 901 disappeared.
" ww.audiokarma.org/forums/showthread.php?t=350680
urapnes1 is offline  
post #1034 of 2920 Old 06-25-2014, 05:12 PM
 
Join Date: Jun 2014
Location: Canada
Posts: 39
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 29 Post(s)
Liked: 2
Quote:
Originally Posted by arnyk View Post
Global demonization if there ever was any.

The author has no idea of the details of all audio ABX tests simply because so many ABX tests have been done in private that nobody know any such thing.

Amir has been complaining that I have not documented many of the ABX tests that I've done. I am therefore looking to this author's detailed deconstruction any of them. After all, he's the one that used the words "all encompassing".


Global actualization, perhaps!

Private testing - is private and therefore has never been presented as measure of anything. One can reasonably assume that if the results were conclusive, repeatable and able to with stand professional scrutiny that they would have been shared in some form. In the absence of such sharing's, one can only assume that the aforementioned was not the case. I also believe Arny that if you had such a document you would have wielded it ages ago; hence Amir's taunting of you, to deliver such.


Of what has been published and shared, in various forms, has failed to produce universal, repeatable truths, this is fact - like it or not. Null, result, after Null result, even in clearly biased settings. I don't know of a single manufacturer in North America (there is bound to be a couple) that has a audio ABX set-up, outside of a few speaker manufacturers, and I have it on good authority that they have been decommissioned (In Canada).


The standard mix of test equipment, designed for product development, debugging and goodness measurement, is all based in automated, to semi-automated signal agitation(s), acquisition and analysis. Not one company uses an ABX Comparator, during design, debugging and goodness measurement. I work for a company that owns several manufacturing plants around the world and has hundreds of engineers in its employ, and we don't have a single audio ABX comparator. We do have hundreds of peace's of test equipment, from all major producers of such. An interest factoid, 1/3 of our business comes from the sale of loudspeakers, but yet we don't inventory a single audio ABX comparator. If they were of value to any degree, we and other manufacturers would inventory at least one. We have $80K analyzers, what's $800-1000.00 for and audio ABX Comparator - it's chump change.


Like I've said, there is absolutely no credibility to the current realm of audio ABX testing's, they're antidotal at best. A fully informed, objective person, cannot reach any other conclusion. To be fair perhaps, I acknowledge that a big smoke cloud was produced throughout the 90's that initially mislead a great many, but by the mid 2000's, it was smothered and with it the manufacturing of Audio ABX comparators (which very few purchased, even during its hayday). Again, today, a fully informed, objective person, cannot reach any other conclusion. If you have, then you're not fully informed, objective, or you're selling something other than truths (to others, as well as yourself) and perhaps a combination, or a blend of the three may be in play.


So you've pushed and I have laid my cards on the preverbal table: I challenge anyone to provided me with just one fully documented, proctored audio ABX test session (just one). I will study it deeply and if I am unable to find a short-coming (which of coarse I will disclose for group scrutiny) you will have won me over (and I will also eat a large portion of humble pie).


If the goal isn't to win people over, to convince them of your truth, perhaps the truth, but rather to bully, prod and make light of, then don't send me a darn thing, and I will put you on ignore, so that we can all move on.


But if this challenge is met, and I succeed in discovering legitimate short-comings, even one, I ask but just one thing from those of you whom are mislead; what I am about to ask is for their benefit, not my own. I ask that you seriously, and completely re-investigate your prerogatives and the foundations upon which they have been formed. I ask for nothing more - no gloat, no glory!


No gamesmanship here - just direct communications, straight across the bow.

Last edited by dB Cookster; 06-25-2014 at 06:13 PM.
dB Cookster is offline  
post #1035 of 2920 Old 06-25-2014, 05:24 PM
 
Join Date: Jun 2014
Location: Canada
Posts: 39
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 29 Post(s)
Liked: 2
Quote:
Originally Posted by hevi View Post
I do not agree with your disqualification of ABX listening tests in general -DBT is a good practise, and the criteria how you select your test subjects is in my mind another dimension of the "testing problem". It is really a matter of what you want to study (now speaking generally an not specifically about audio listening tests). In many cases you want to study the "general public", to find different sensory thresholds for the broad public. In other studies you may want to find the absolute limit of what is possible to detect (and of course, all combinations in between).

With that said, the latter par of the blue in your quote pretty much sums up how the Swedish AES goes about its testing. They use a small group of listeners (3-4 each session) where the majority of the group have proven to be very good at detecting colorations under blind conditions in the past, they do an open "training session" where they discuss what coloration they think they hear, and the they do a DBT A/B session.


Their test results are somewhat different from the conclusions arnyk et. al. have come to. They (Swedish AES) often find statistically significant differences between DUTs under DBT conditions.

Their latest test of two DACs (Denon 300USB and Cambridge Audio DACMagic plus), for example, the DACMagic was detected 10 out of 10 times by two out of three listeners while the third listener answered pretty much randomly. The Denon was also detected (one of the listeners that had 10/10 on the DACMagic had 9/10 on the Denon). The comparison was not against each other, but against a reference CD-plyer that has yet to be detected in a DBT.

Fair enough!
Interesting but suspicious results; If you're so inclined, please shoot me link or few?
dB Cookster is offline  
post #1036 of 2920 Old 06-25-2014, 05:32 PM
 
Join Date: Jun 2014
Location: Canada
Posts: 39
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 29 Post(s)
Liked: 2
Quote:
Originally Posted by urapnes1 View Post
In case anyone cares, somewhere in the lifecycle of the 901 the wiring scheme was changed at least twice. From a combination of series and parallel drivers to just series. There was an interim model which had the ability to split the speaker up electrically:

Here is a quick bit that I found on the Series III

"The spacial effect and control on the original Bose receiver depended upon the Series III speaker (can't remember if it carried over to the Series IV). Effectively what you had was a receiver with 4 amps. 2 of these amps drove one speaker and the other 2 amps drove the other speaker.

How did this work? Well, there were 3 terminals on the bottom of the Series III speakers. The speakers were wired so that the inner 4 drivers (referenced to as you would face the 901) could be hooked up separately while the outer 4 drivers and the front-facing driver were wired to the other amp on that side. So, you ran 3 wires to the each of the speakers.

Now, in the receiver, the spatial control would route the stereo signal to L and R as in any other receiver. When you started moving the spatial control, the opposite signal would be routed to the speaker's inner 4 drivers. That is, on the left hand speaker, the inner 4 drivers would start to have part of the R signal playing through it. Same on the R where the L signal would start appearing on the inner 4 drivers. Since these inner 4 drivers faced toward the middle, the effect was to fill in center with an opposite channel thus allowing you to control how much blend there was during playback.

The fact was, however, that the whole thing was far too complicated for most folks and required additional understanding during hookup. The whole Spatial Control technique died off quickly and the magic 3rd connector on the 901 disappeared.
" ww.audiokarma.org/forums/showthread.php?t=350680

Interesting factoid! I had often seen these speakers on demo - display, but didn't pay them sufficient attention to catch this. I wish I had.
dB Cookster is offline  
post #1037 of 2920 Old 06-25-2014, 05:54 PM
Senior Member
 
hevi's Avatar
 
Join Date: Jan 2007
Posts: 365
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 33 Post(s)
Liked: 48
Quote:
Originally Posted by dB Cookster View Post
Fair enough!
Interesting but suspicious results; If you're so inclined, please shoot me link or few?

There are very few public links. The (only) one that comes to mind is the "Bryston intervention" http://www.4audio.rs/upload/File/Bry...eview%2049.pdf)", but that one has next to none info on how they actually go about their tests in detail (and it is a *really* crappy translation, IMHO).

hevi is offline  
post #1038 of 2920 Old 06-25-2014, 06:02 PM
 
Join Date: Jun 2014
Location: Canada
Posts: 39
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 29 Post(s)
Liked: 2
Quote:
Originally Posted by hevi View Post
There are very few public links. The (only) one that comes to mind is the "Bryston intervention" http://www.4audio.rs/upload/File/Bry...eview%2049.pdf)", but that one has next to none info on how they actually go about their tests in detail (and it is a *really* crappy translation, IMHO).

Thanks. To bad I can't read Swedish. This isn't the first time that I heard of this. They use a reactive load of some type, when subjectively and objectively comparing / measuring amplifiers, correct?

Last edited by dB Cookster; 06-25-2014 at 06:19 PM.
dB Cookster is offline  
post #1039 of 2920 Old 06-25-2014, 06:13 PM - Thread Starter
AVS Addicted Member
 
amirm's Avatar
 
Join Date: Jan 2002
Location: Washington State
Posts: 18,478
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 1061 Post(s)
Liked: 557
Quote:
Originally Posted by hevi View Post
There are very few public links. The (only) one that comes to mind is the "Bryston intervention" http://www.4audio.rs/upload/File/Bry...eview%2049.pdf)", but that one has next to none info on how they actually go about their tests in detail (and it is a *really* crappy translation, IMHO).
Years ago they had a bunch of articles on their web site. Machine translation at the time was really, really bad but I still enjoyed reading through it. Unfortunately all of those pages are gone. I don't know why they would remove them.

Amir
Retired Technology Insider
Founder, Madrona Digital
"Insist on Quality Engineering"
amirm is offline  
post #1040 of 2920 Old 06-25-2014, 06:13 PM
Senior Member
 
hevi's Avatar
 
Join Date: Jan 2007
Posts: 365
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 33 Post(s)
Liked: 48
Quote:
Originally Posted by dB Cookster View Post
Thanks. To bad can't read Swedish. This isn't the first time that I heard of this. They use a reactive load of some type, when subjectively and objectively comparing / measuring amplifiers, correct?

They use an artificial speaker load mimicking a semi-difficult speaker when testing amps:
http://www.sonicdesign.se/amptest.htm

hevi is offline  
post #1041 of 2920 Old 06-25-2014, 06:38 PM
 
arnyk's Avatar
 
Join Date: Oct 2002
Location: Grosse Pointe Woods, MI
Posts: 14,530
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 851 Post(s)
Liked: 1205
Quote:
Originally Posted by hevi View Post
Yes. They have not always done rigid DBTs, but since several years they do, and they still detect DUTs.





I am sorry to say, if you're not comfortable with my sketchy summarisations of their efforts, you need to pay the membership fee and learn Swedish, and then you're good to go.
I'm sorry to say that I am way to busy to play "I have a secret".
arnyk is offline  
post #1042 of 2920 Old 06-25-2014, 06:40 PM
 
Join Date: Jun 2014
Location: Canada
Posts: 39
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 29 Post(s)
Liked: 2
Quote:
Originally Posted by hevi View Post
They use an artificial speaker load mimicking a semi-difficult speaker when testing amps:
http://www.sonicdesign.se/amptest.htm

I followed this link and the Bryston link: Those Canadian guy's eh! Pretty cool dudes after all!


There is definitely some smoke here. Thanks for presenting this. I was looking for this type find, when I joined.


I will continue researching this and share my discoveries with you. I may need you to clarify some things along the way.


Thanks again.
dB Cookster is offline  
post #1043 of 2920 Old 06-25-2014, 06:46 PM
 
arnyk's Avatar
 
Join Date: Oct 2002
Location: Grosse Pointe Woods, MI
Posts: 14,530
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 851 Post(s)
Liked: 1205
Quote:
Originally Posted by dB Cookster View Post
Global actualization, perhaps!

Private testing - is private and therefore has never been presented as measure of anything. One can reasonably assume that if the results were conclusive, repeatable and able to with stand professional scrutiny that they would have been shared in some form. In the absence of such sharing's, one can only assume that the aforementioned was not the case. I also believe Arny that if you had such a document you would have wielded it ages ago; hence Amir's taunting of you, to deliver such.
Amir taunts me because that's the best he can do.

Your claim that no valid ABX test has ever been done has exactly as much credibility as its claimant who hides behind a made-up alias.

If you understood the difference between double talk and reasoned discussions, you'd probably prefer to post the latter, not the former.

Last edited by arnyk; 06-25-2014 at 06:49 PM.
arnyk is offline  
post #1044 of 2920 Old 06-25-2014, 06:59 PM
 
Join Date: Jun 2014
Location: Canada
Posts: 39
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 29 Post(s)
Liked: 2
Quote:
Originally Posted by arnyk View Post
Amir taunts me because that's the best he can do.

Your claim that no valid ABX test has ever been done has exactly as much credibility as its claimant who hides behind an made-up alias.

If you understood the difference between double talk and reasoned discussions, you'd probably prefer to post the latter, not the former.

So, in other words, you are declining my direct challenge. Curious, but Fair enough!


You had your chance to convince me that I got things all wrong. But in the absence of any proof, I remain un-swayed.


I respectfully agree to disagree with you.


Now perhaps we can move on to a new discussion.
dB Cookster is offline  
post #1045 of 2920 Old 06-25-2014, 07:24 PM
AVS Special Member
 
Tack's Avatar
 
Join Date: Mar 2004
Location: Valencia, Ca
Posts: 3,885
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 458 Post(s)
Liked: 925
Quote:
Originally Posted by dB Cookster View Post

I respectfully agree to disagree with you.
Go away or I shall taunt you again!




Quote:
Originally Posted by dB Cookster View Post
Now perhaps we can move on to a new discussion.

Just between you and me, I don't think anyone is buying your new alias. The faux ESL is a little heavy handed. There's always next time
Frank Derks, koturban and andyc56 like this.
Tack is offline  
post #1046 of 2920 Old 06-25-2014, 07:37 PM - Thread Starter
AVS Addicted Member
 
amirm's Avatar
 
Join Date: Jan 2002
Location: Washington State
Posts: 18,478
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 1061 Post(s)
Liked: 557
Quote:
Originally Posted by UndersAVS View Post
The fact of the matter is that you dismissed the author's work in another discussion; the "Jitter" discussion. When I posted the Reviewer's information, you replied:
I apologize as my two-digit IQ is not enabling me to understand your post. But I did note the reference to the Onkyo HDMI review from NWAVguy.

I wonder if you saw the reference to ground loop in the comments section? If not, lets look at that: http://archimago.blogspot.com/2013/1...receivers.html

Here, he is testing the analog pass-through in the Onkyo TX-NR1009 AVR. Initially he finds it to have excellent performance with noise levels that are down some 110 db. But a remarkable thing happens when he hooks up a Blu-ray player to its HDMI input and connects the HDMI output to his display:

As excited as I am about those results above, a modern AV receiver is meant to process HDMI and be connected to a TV. This receiver has a HDMI "passthrough" which is essentially always in operation and for most people, it would not be left in "Pure Audio" mode with all the video gear disconnected. As such, look what happens when I connect my LG 55LW5600 TV (55" passive 3D, LED TV from 2011) to the ONKYO and repeated the measurements:

Noise floor raises way, way higher to -77 to -79 db:



Ugly, my friends... Clearly having the TV HDMI connected has injected very significant amount of noise in the system! Dynamic range has dropped to ~80dB across the board (equivalent to 13-bits). Notice a very strong 60Hz mains hum which is even showing up in the frequency response graph... What is happening here is that I'm seeing the effect of ground loops. There are ways to overcome this of course.

Ugly my friends! Recall that I pointed out the same thing in my measurements. That even when using S/PDIF input, mere act of connecting the source to the HDMI processor/AVR degraded its performance. That degradation was very small but this one is massive.

So don't go celebrating that "this reviewer" said HDMI is fine. It is not fine. HDMI electrically couples of the products together, making a long chain that can suffer from ground loops and noise transmission.

Notice how HDMI performance is not predictable. Its noise/distortion/jitter varies substantially from design to design. So any paper analysis of its audibility can only be accurate for that one model for which you have measurements. Lacking that, there is no thing you can say about its performance, lest you would have been able to predict a 40 db drop in dynamic range of the above Onkyo out of the blue. And would have measurements for your total system and not just the AVR.

Again, this was all on the NWAVguy's web site. So please read the information you are citing. Don't just go for headlines. If not me, there will be another double digit IQ person who would call you on lack of due diligence.

Amir
Retired Technology Insider
Founder, Madrona Digital
"Insist on Quality Engineering"
amirm is offline  
post #1047 of 2920 Old 06-25-2014, 07:43 PM
Advanced Member
 
andyc56's Avatar
 
Join Date: Feb 2013
Posts: 682
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 17 Post(s)
Liked: 216
Quote:
Originally Posted by Tack View Post
LOL! Now I'll have to create some sockpuppets so I can "like" your post multiple times (along with my own posts too)!

Last edited by andyc56; 06-25-2014 at 07:46 PM.
andyc56 is offline  
post #1048 of 2920 Old 06-25-2014, 07:43 PM
 
Join Date: Jun 2014
Location: Canada
Posts: 39
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 29 Post(s)
Liked: 2
Quote:
Originally Posted by Tack View Post
Go away or I shall taunt you again!







Just between you and me, I don't think anyone is buying your new alias. The faux ESL is a little heavy handed. There's always next time

Who is it, that you think I am?
dB Cookster is offline  
post #1049 of 2920 Old 06-25-2014, 10:52 PM
AVS Addicted Member
 
Chu Gai's Avatar
 
Join Date: Sep 2002
Location: NYC area
Posts: 15,051
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 363 Post(s)
Liked: 629
Being that you're so vague when you write long posts, you might be a politician. A protege of Rob Ford?

"I've found that when you want to know the truth about someone that someone is probably the last person you should ask." - Gregory House
Chu Gai is online now  
post #1050 of 2920 Old 06-26-2014, 02:56 AM
Senior Member
 
hevi's Avatar
 
Join Date: Jan 2007
Posts: 365
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 33 Post(s)
Liked: 48
Quote:
Originally Posted by arnyk View Post
I'm sorry to say that I am way to busy to play "I have a secret".

It was not a game invitation, it was an honnest answer to your question.


To me, who speak the language, there is an obvious disonance between what Swedish AES have found in several of their tests, and what you and others lay forward here.

hevi is offline  
Closed Thread Audio Theory, Setup, and Chat

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page


Forum Jump: 

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off