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We are discussing it. Missed something? Do you have any evidence to add about the endorsements being paid for or the determination of the ability of the cords or conditioners simply being rubber stamped or are you in just to try to stir the pot?
 

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An electrical engineers perspective on the Nordost video.


First, skip the video, the pdf is available on their website.


This isn't scientific, we don't know any of the controls, the nature of the testing equipment, vibrations present in the room, etc. We need the entire test setup, the source file and the ability to reproduce it in other locations to call it scientifically valid.


Ignoring that and moving on to their claims....


First, what they are doing is looking at a raw PCM file, raw audio samples.


They take this raw PCM, burn it to a CD and play it through the player, then sample it with a (hopefully) high end ADC to get it back into the computer, then compare the samples.


The entire thing is really 'blah' they don't mention how they overlay the signals, they also don't mention how the signal was sampled. Presuming this is just a CD player the audio is stored as 16bit 44.1khz audio.


To directly sample the output of the player and compare it to the source with any accuracy they will need to highly oversample the signal with the ADC and down convert it to 44.1khz carefully (with an appropriate algorithm). Otherwise they have no idea how the sampling points line up. The results could be very random if they just try to sample it randomly with a 44.1khz rate for the ADC. One test could be started at the perfect time and the sampling points overlay very well, another test could be started at the wrong time and the sampling points could lie directly between the sampling points in the source in the time domain. Of course there is also the issue of jitter on both involved clocks to deal with as neither will be exactly 44.1khz.


This actually gets more complicated on these 'high end' cd players as they usually take the output of the CD at 44.1khz, massively up sample it (for some unknown reason to me) then spit it out through high sampling rate DAC's. Annoying this usually results is a 44.1khz to 192khz conversion which is just bad as 192 is not a multiple of 44.1 so some tricky has to be done on the samples to make the conversion properly. The signal then goes through a reconstruction filter, gets fed into a line driver and spit out the line level out.


With all the sampling rate conversion going on in this signal chain trying to compare anything to the source samples as a single case is a lost cause.


This offset in sampling timing could account for some of the slope variations they mention in the video, but are curiously absent in the pdf version. Sampling offsets are also quite effective at messing up FFT's. As an aside whats up with all the high frequency noise on the FFT with their equipment hooked up?


At the end of the paper they claim that many of the differences present in the first test are the result of are greater variation in group delay for the stock setup which should be the real focus of study and could also be largely influenced by sampling rate conversion after capture of the signal.


This is really where i have a hard problem with the paper. I can actually think of a few ways that the power conditioner and the isolation table could actually remove noise from the system. I can only think of 1 far fetched way in which group delay could be effected.


All this comes down to needing more information on the test setup as well as running many many tests and averaging the results to get to something conclusive.


The way i would do this test is to use two as close to identical setups as possible and compare the audio output in the analog world with an oscilloscope, just subtract the signals from each other, which any half decent scope can do in real time. Get a base line with both units having the same power/stand, then change one and see if there is any difference.


Keep in kind i have done 0 tests, but from a circuit design stand point the following are at least theoretically possible ways in which their products could provide some benefit, i highly doubt they do or they would just measure this and publish it.


Vibration:

Generally has little to no effect on well designed PCB's and IC's. However most audio equipment i've opened up likes to make large use of inductors (for good reason) and large components with occasionally long leads.


Inductors generate a magnetic flux field, depending on the current sometimes a quite large magnetic field, that is after all, how they store energy.


Even shielded inductors generate a field inside the shielded enclosure. Whenever something conductive moves inside a magnetic flux field it can generate currents. So if have an inductor with a large field and its vibrating, unevenly as is usually the case, it will generate some transients on the signal passing through that inductor as well as currents on other conductive items inside its flux field. There are a lot of variables to this, the nature of vibrations, the rate of change of the flux field, etc.


I would expect currents generated by this effect to be quite small. But this could effect any piece of metal within the flux field of the inductor, this is part of the reason why the inductors on the power supply input are usually shielded and isolated from the audio circuitry but not all inductors are well protected.


If vibrations are introducing currents in other parts of the circuit these could be transfered to the audio signal. In contrast to what an earlier posted said, the DC power generated for use on the PCB of any electronic device is not perfect. It will always contain some higher frequency. Circuits designed for audio use are designed with cleaner power supplies and with high power supply rejection ratios (the amount of noise that couples from the power supply rails to the output of a given device). Numbers around 50-65db, varying with frequency are normal for relatively high end DACs. Thus noise present on the power supply lines for any of the supplies in the system can make it way to the signal path. In well designed systems this is accounted for and designed to be at or under the noise floor. Of course if there is a ton of noise overlaid on your mains line it could be audible. Again thats unlikely, unless your trying to run an audio demonstration at a trade show with a crap power feed and trip the breaker
))


As for the group delay. The induced current could, completely theoretically and unlikely, mess with the group delay across the frequency spectrum for some filter topologies. Again I highly doubt this would have an impact.


tl:dr


Comparison of the signals to a digital master on a sample by sample basis with so much sampling rate conversion going on is foolish.


Do the comparison in the analog world, run it 100+ times and average the results.


Publish your entire test setup and source track so others can verify your results.
 

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Quote:
Originally Posted by KeithR /forum/post/18921153


because the only reason you are on this site is to spout objectivist dogma and not further a rational discussion when questioned.


the value you even add to that debate is questionable, at best unlike several members/objectivists of this forum that i enjoy reading....

Oh dear. So if someone won't get into your pissing match, you infer reasons as to why I am on this site. Again, the site has the word Science in its title. So I suggest you accept that or move on.


A rational discussion demands rationality. I suspect you don't want to "discuss" anything, since you are not prepared to evolve some long-held world-view. And to think we "objectivists" are accused of being closed-minded. Sheesh.
 

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Quote:
Originally Posted by theborg7of7 /forum/post/18922310


Charles,


Is this yet another claim that a determination of sound quality change was gained by BS methods? Do you have evidence to back your claim? Think not. Do you really think these well-established studios and musicians simply plugged in a cord or power conditioner, yawned, and said, 'Well, hmmm, yah, I think I hear a difference, maybe... Hey, Frank, do you think you hear a difference? Put down your sandwich for a minute. That's okay, I'll put you down as a yes.' Do you really think they would damage their reputations by putting their endorsements in writing? Perhaps they all were so overwhelmed by the nice bag the cord might have come in that the engineers automatically thought, 'Boy, this HAS to sound good.' You have got to be kidding.


But then, taking these endorsements into consideration would go against the sacred truth that everything about electronics is already known. (I just got a flashback to an old Star Trek episode when the Oracle chanted to a girl who questioned new ideas, '...the truth of Yonatta is YOUR truth...' Remember?)


I think it might be a good time for objectivists to gaze at the 'I want to believe, I want to believe' posters on the wall.


Happy listening.

What reputation to ruin??? They claimed it made a difference and the faithful just gobbles up that bs nonsense. So, their reputation is intact.


As to coming to that conclusion, there is zero evidence that they went through a proper, bias controlled evaluation. But, if you have evidence to support their claims that they have such evidence, I can change my mind. It better be good evidence. Otherwise, it was as you wrote, they plugged it in and their imagination took over. Not hard, rather easy process.
 

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Quote:
Originally Posted by theborg7of7 /forum/post/18922310



Is this yet another claim that a determination of sound quality change was gained by BS methods? Do you have evidence to back your claim? Think not. Do you really think these well-established studios and musicians simply plugged in a cord or power conditioner, yawned, and said, 'Well, hmmm, yah, I think I hear a difference, maybe... Hey, Frank, do you think you hear a difference? Put down your sandwich for a minute. That's okay, I'll put you down as a yes.' Do you really think they would damage their reputations by putting their endorsements in writing? Perhaps they all were so overwhelmed by the nice bag the cord might have come in that the engineers automatically thought, 'Boy, this HAS to sound good.' You have got to be kidding.


Actually, it's probably ALL of the above. Yes, I would not be at all surprised if they did all of that BS. As long as it did nothing bad and made nothing worse, and that they got the cables either for free or with some other attached "spiffs" to go along with the cables, that they were willing to say all of that garbage.



Even with all their so called positive testimonials. You certainly have not provided ANY evidence at all, that the cables they are shilling for, actually sounded any better or even really improved anything at all!
 

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Quote:
Originally Posted by theborg7of7 /forum/post/18917855


More delusional people?

http://www.shunyata.com/Content/endorsements-Man.html

http://www.shunyata.com/Content/endorsements-Prof.html

No more delusional than people like,


Herbie Hancock who recommends Bose.

Tiger Woods who uses Nike (just about always) equipment.

Charlie Sheen who like Hanes t-shirts.

The recently concluded World Cup where Budweiser was the official beer.

Britney Spears really enjoys Pepsi.

Charles Barkley might put you in his fav 5 on T-Mobile.

Gene Simmons & KISS couldn't do what they do without Dr. Pepper.


Yes, they're not delusional and they all get paid in different ways.
 

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Quote:
Originally Posted by Johnla /forum/post/18925415


Even with all their so called positive testimonials.

Those are easy to get. Just remove the ones they don't want the public to see out of whatever the number of gathered testimonials they have.
 

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You must mean, these.

 

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Johnia,


Thank you. You provided the line I was waiting for. I know someone would say it.


"Even with all their so called positive testimonials. You certainly have not provided ANY evidence at all, that the cables they are shilling for, actually sounded any better or even really improved anything at all!"


Please let me know which company or person claimed '...it did nothing bad and made nothing worse...' I can't find it. Is this something you are imagining (perceiving
) or have actually read?


Even if all these people and companies did a perfect series of DBT and passed with flying colours, the response from this forum would be 'you didn't provide any PROOF.' I predicted this. In other words, the DBT is a scam. It is only the first line of defense. If anyone gets through that one, the 'no proof' line will quickly follow. If proof was provided, then the next line would be 'it needs to be repeated hundreds of times.' If that was done, then the next would probably be 'the data must be false because everything in electronics is already known.'


Your use of terms shows your bias in this situation. The use of 'so-called,' 'shilling for,' and 'spiffs,' 'BS,' 'garbage'...says it all. Those are the terms you use when you really don't really have a come-back but want to slander the company or person in question. Good (actually not) try. I think the next one would be something like 'I'm taking my ball and going HOME!'



Chu Gai,


You are comparing Charlie Sheen and Hanes t-shirts to the topic of this forum? Huh? Yes, I would imagine these celebs (if you can call them that) were paid by the companies. They are featured in commercials. Have you seen any of the musicians or studios on television doing commercials for Shunyata? Your comparisons are absurd.


Again, do you have evidence of Shunyata being paid? Do a quick search of 'purchased' in the professional endorsement URL I provided. The writers of the endorsements bought the products. I've never heard of Sony promoting Pepsi, Crest Studios promoting Hanes t-shirts, or Look Out Studios promoting Dr. Pepper, have you?


dimonia,


I'm sure it's easy to get free positive endorsements from Lucas Films. Sony, and Wilson Audio. Sure...you stick with that one.
 

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It's a stretch to compare cable manufacturers with false psychics and ESP guys. Anyone can fake anything; it need not indict the entire field of study. However, that is convenient for debunkers. Lazy, but convenient.

Quote:
Originally Posted by theborg7of7 /forum/post/18926422


dimonia,


I'm sure it's easy to get free positive endorsements from Lucas Films. Sony, and Wilson Audio. Sure...you stick with that one.

Look, we can't even be sure that diomania speaks English as a first language, so we can't be sure he even understands what's going on around here.
 

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Revealing to observe the posts Borg7of7 and jibberjabber choose not to respond to, though hardly surprising.
 

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Quote:
Originally Posted by theborg7of7 /forum/post/18926422


Even if all these people and companies did a perfect series of DBT and passed with flying colours, the response from this forum would be 'you didn't provide any PROOF.'

Rubbish. I would be extremely interested to read of such a test and provided it was done with reasonable rigour would not dismiss is as 'no proof' or invalid.
 

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Quote:
Originally Posted by theborg7of7 /forum/post/18926422


Chu Gai,


You are comparing Charlie Sheen and Hanes t-shirts to the topic of this forum? Huh?

Don't forget Herbie Hancock too. I'm lumping them all together for the simple reason that they all provide endorsements in exchange for some sort of compensation.

Quote:
Yes, I would imagine these celebs (if you can call them that) were paid by the companies. They are featured in commercials. Have you seen any of the musicians or studios on television doing commercials for Shunyata? Your comparisons are absurd.

Actually from the links you provided, if I go to the manufacturer websites I see no recommendation by the various companies for Shunyata products. Why is that? And of course Meridian and Wilson aren't featured in any televised commercials. They don't have the funds to pull anything like that off because they're too small and I rather doubt there'd be any return on that sort of investment. They get some freebies and in exchange allow their names (although who the salespeople are is quite the mystery) to be used.

Quote:
Again, do you have evidence of Shunyata being paid? Do a quick search of 'purchased' in the professional endorsement URL I provided. The writers of the endorsements bought the products. I've never heard of Sony promoting Pepsi, Crest Studios promoting Hanes t-shirts, or Look Out Studios promoting Dr. Pepper, have you?

Well, not again. It's the first time you brought it up to me. People don't let their names out for free unless they're suckers. One hand always washes the other. I haven't heard of those studios promoting those things but I'll bet someone there has quenched their thirst with Pepsi, gone to work in Hanes undies, and maybe sometimes they feel like a Pepper. Why Charlie Sheen just might have some Sony products but Charlie's not going to let Sony use his name unless he's compensated. Neither are the studios.
Quote:
dimonia,


I'm sure it's easy to get free positive endorsements from Lucas Films. Sony, and Wilson Audio. Sure...you stick with that one.

Lucas Films, the company has not made a positive endorsement on their website. Neither has Wilson. Or Sony.
 

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Quote:
Originally Posted by CruelInventions /forum/post/18927306


Revealing to observe the posts Borg7of7 and jibberjabber choose not to respond to, though hardly surprising.

I appreciate the compliment of accusing me of not responding to random spatterings. I will however address this:

Quote:
Originally Posted by terry j /forum/post/18913346


Jibber, what are you personal boundaries in audio??


Chu mentioned that prior to examining something it needs to be determined that the 'thing' exists. Makes sense to me, but not to you it seems.

The idea is to investigate whether a phenomenon exists in the first place, then investigate its merit or lack thereof. Some like to put the cart before the horse here.

Quote:
What are some examples of things you would NOT pursue on first glance?


Peter Belt (sorry for bringing up paranormal) for example, there are some that swear by it. Should we go looking for and funding studies to investigate them??


What about this one? http://www.theadvancedaudiophile.com...que/index.html


Or this?? http://www.theadvancedaudiophile.com...ent/index.html


(just grabbed at random)


He obviously swears by them, should we first find out if they are real or potentially real before devoting time and effort in investigation, or just go for it?


If so why so, if not why not.


Just trying to get where your own boundaries lie. We all have them, just at different points.

Since it's harmless to investigate efficacy on any audio product, why not?

Quote:
I mean I'd hate for the answer to be 'I think I hear cables/power cords personally, so want them investigated, yet that sounds like rubbish so ignore'.


That would be hypocritical.

This isn't about me, as much as you'd like it to be. This is a clear phenomenon that obviously exists on some plane, and it obviously isn't simply imagination.

Quote:
OR, sort the wheat from the chaff and only check out those that have merit??

I just think this is funny. We don't even know what is valid yet, but you would like to prejudge the issue. The process of investigation is what separates the wheat from the chaff. We can't assume something exists or not prior to determining the facts.

Quote:
Hmm, how would we sort the wheat from the chaff I wonder....

See above. Don't rush to verdict on a topic prior to having all the information. I know science likes to do this, but let's see if this shakes out differently.
 

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Quote:
Originally Posted by jpjibberjabber /forum/post/18926738


Look, we can't even be sure that diomania speaks English as a first language, so we can't be sure he even understands what's going on around here.

I see, so if English is a first language for someone, he or she understands what's going on around here. Looks like the reality is slapping you on the face.
 

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What are we discussing?
 

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Quote:
Originally Posted by theborg7of7 /forum/post/18926422


...

Even if all these people and companies did a perfect series of DBT and passed with flying colours, the response from this forum would be 'you didn't provide any PROOF.' I predicted this. In other words, the DBT is a scam. .....

Well, one way to find out what the responses will be is to present those 'perfect' DBTs. Then, we can go from there, no? Speculating in the meantime is just that, sheer speculation, YES!


And, since you are not a psychic, your predictions are unreliable at best; come to think of it, even if you claimed to be one, it would still be the same.
 

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Quote:
Originally Posted by jpjibberjabber /forum/post/18926738


It's a stretch to compare cable manufacturers with false psychics and ESP guys.....

You mean there are real psychics out there????
Who??? Randi is looking for that person/s
 
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