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post #31 of 56
^^ what if A/B type testing is not a good way to evaluate differences in audio but instead differences are perceived by using components over time.

this is an interesting cable experiment: http://www.hometheaterhifi.com/volum...1-12-2000.html
post #32 of 56
Quote:
Originally Posted by vcoheda View Post
^^ what if A/B type testing is not a good way to evaluate differences in audio but instead differences are perceived by using components over time.

this is an interesting cable experiment: Product Review
That statement itself is something that deserves to be tested. It's certainly counterintuitive, considering how short the human memory for sound is.
post #33 of 56
Quote:
Originally Posted by monolith View Post
That statement itself is something that deserves to be tested. It's certainly counterintuitive, considering how short the human memory for sound is.
X2.
post #34 of 56
Quote:
Originally Posted by monolith View Post
That statement itself is something that deserves to be tested. It's certainly counterintuitive, considering how short the human memory for sound is.
that's fair.

then i suppose the validity of A/B tests with regard to audio is also something that needs testing.
post #35 of 56
I'm of the opinion that most of the sound difference people hear between something like a 200 dollar custom LOD and my 30 dollar one is all in the mind.

I know for a fact I enjoy things more when I pay for them and especially if I pay a lot for them. I noticed this when it come to videogames, I'm not really interested in playing games I've gotten for free despite how good they are but if I payed 50 dollars for one I play it a lot and do enjoy it a lot more. (Really not sure why this is)

Bottom line I don't think a custom LOD sounds better then my 30 dollar one. I've heard both back to back out of the same headphones and amp and did not notice a difference. This probably only applies as long as I don't own one, however. =/

I'm only human, and I do realize a direct relationship between expenditure and enjoyment that I can't control despite being totally aware of it.

Personally I'd be very interested on more research on this effect ^, especially amongst audiophiles.

I do hope you come out with good tests, I am a believer in the validity of DBT and wished it wasn't so frowned upon here as it could provide a wealth of information to those considering whether it's really worth spending 200 dollars on a cable when theirs is fine.

I don't think factual information about the differences (or not differences) in cables should be suppressed just for the name of preventing argument or debate. Maybe it has something to do with the fact that this is a sponsored forum, I don't know.
post #36 of 56
Quote:
Originally Posted by monolith View Post
That statement itself is something that deserves to be tested. It's certainly counterintuitive, considering how short the human memory for sound is.
It's true that human aural memory is very short, but consider this: if you heard some stranger say one word, would you then, the next day, be able to pick them out in a crowded bar by their voice alone? Probably not. Yet, I don't think most would disagree that people can pick out the voices of people they're familiar with in the same situation.

The distinction to be made is that things other than aural memory affect not only our perception but our interpretation of sound. What we perceive is strongly dependent on our aural memory, but what we interpret, as in the case of learning the subtleties of and picking out the sound of someone's voice, is more complicated than just what's contained in our very short aural memory.

I know this personally for a fact because when doing ABXs, I initially found it hard to distinguish between a particular passage that I suspected sounded different. After a while (an hour or so), I learned the nuances of the sounds I was hearing and could distinguish the passages consistently. The p-value of the tests went from initially no significance (p > 0.05) to (an hour later) very significant (p << 0.001).

Although I don't have a position on cables, I have to agree wih vcoheda and sean3089 that if an audio-related DBT is going to have any weight behind it, it has to be carried out over a period of time long enough that the listener can get aquainted with the sound, ideally a few weeks or longer.
post #37 of 56
Quote:
Originally Posted by asher7323 View Post
I do hope you come out with good tests, I am a believer in the validity of DBT and wished it wasn't so frowned upon here as it could provide a wealth of information to those considering whether it's really worth spending 200 dollars on a cable when theirs is fine.
This is an interesting statement, because to the best of my knowledge, the validity of DBT in an audio setting has never been demonstrated. That is, DBT has not been shown to be sensitive to known, audible, and measurable differences among pieces of audio gear, nor has the effect of DBT on such differences been examined. The validity of DBT in pharmacology is known. The validity of DBT in audio is not known.
post #38 of 56
Quote:
Originally Posted by Hirsch View Post
DBT has not been shown to be sensitive to known, audible, and measurable differences among pieces of audio gear, nor has the effect of DBT on such differences been examined.
What evidence could you accept that would prove to you that DBT testing
is a valid method of testing audio?
post #39 of 56
Ah, you don't need to ask for proof that listener-blind testing is valid, nor are there any grounds whatsoever for dismissing it, when it reveals a difference.

This is self-evident. If a listener is able to reliably prove he prefers set-up 1 to set-up 2, through randomized, blinded, fair, no knowledge leakage, all-other-things-equal A/B testing (with random assignments of 1 and 2 to A or B), then that's that.

He will have the same reaction at home, and therefore should buy or use the setup just revealed as the one he prefers. If it is way more expensive, well at least he knows he is paying his money for something.

From this you can draw no conclusion about the population at large. But if this test is repeated over and over, and the same preference is proven, then we can make a population statement.

I think what Hirsch is saying relates to the "no difference revealed" test result. And there we have a real issue: there are lots of reasons to believe that the current DBT experiments being reported may not allow real differences to be noticed. Why? The duration issue so well discussed by b0dhi; the unfortunate focus that A/B/X puts on the wrong goal (as I have argued elsewhere), and other problems.

My point is this: we will find differences in 24/96 vs 16/44.1, we will find differences in rat cables vs better ones, and so on. Careful listener-blind tests will prove these differences -- well that is my prediction.

This will prove that previous DBT tests were flawed.

And then we can get on with enjoying the music.
post #40 of 56
One approach that I think is interesting is similar to a feature in a noise reducing plug for audio that I use. The plug in takes the original signal does it's processing and then inverts the phase and plays back the audio with the similarities nulled out. This enables you to hear how much degradation you noise reduction settings are have in a subjective way.

One could create the same thing for cables, inverting the phase of one set and summing the two signals to null out any similarities. One major issue is that in doing so you could create a system that would be the criticized for compromising the purity of the signal. Introduced more components (most likely active) into the system may make such tests difficult or possibly compromised. Thermal noise and other performance differences between active components may also be left as residual differences in the summed signal. I guess it also place the cable into a situation where it's not actually going to be used in real life. So it's not without it's major problems but I think it's at least an interesting concept that could provided interesting information.

I believe ideas similar to this have been used by David Hafler and others in the design and testing of amps. Rod Elliot has an article about something similar but again focused on amps. "Sound Impairment Monitor (SIM) - Is This The Answer?"
post #41 of 56
Been a while since I have posted. Has anyone mentioned the idea of possibly having a full double blind and scientific measurements done at something like the big Head-Fi meet. I am sure there would be a lot of people from both camps willing to participate.
post #42 of 56
Quote:
Originally Posted by wavoman View Post
I think what Hirsch is saying relates to the "no difference revealed" test result. And there we have a real issue: there are lots of reasons to believe that the current DBT experiments being reported may not allow real differences to be noticed. Why? The duration issue so well discussed by b0dhi; the unfortunate focus that A/B/X puts on the wrong goal (as I have argued elsewhere), and other problems.
Exactly. DBT is a useful control group. When you achieve positive differences, you can rule out expectancy effects as the reason for the positive effect. However, and this is critical, the absence of a positive effect does not necessarily imply a negative effect. If your methodology is not sensitive, you'll get a lot of negative effects masking real differences. So, you need to first test your methods with known differences. These should be included as positive controls in any DBT. If someone does not hear cable differences in DBT, but also cannot detect the positive controls, which should be known, audible effects, we can with some authority say that the method is flawed (or the person is hearing-impaired).

Here's a question for you. Exactly how many people would you need to reliably and repeatedly detect a difference between two cables in order to say that a difference between the cables exists? Assume a blinded study, and all controls needed to insure that no cheat was possible.
post #43 of 56
Quote:
Originally Posted by Hirsch View Post
Here's a question for you. Exactly how many people would you need to reliably and repeatedly detect a difference between two cables in order to say that a difference between the cables exists? Assume a blinded study, and all controls needed to insure that no cheat was possible.
One, with a few caveats.

First, it would have to be really reliably and really repeatedly say 8/10 say 2 or 3 times in a row. Sufficient to rule out pure chance.

Second, if that was the only person who could hear the difference then it would be utterly irrelevant apart from for that one person - you would be saying there is a difference but you (everyone else) cannot hear it which would not be a great marketing slogan for a cable company.
post #44 of 56
Quote:
Originally Posted by nick_charles View Post
One, with a few caveats.

First, it would have to be really reliably and really repeatedly say 8/10 say 2 or 3 times in a row. Sufficient to rule out pure chance.

Second, if that was the only person who could hear the difference then it would be utterly irrelevant apart from for that one person - you would be saying there is a difference but you (everyone else) cannot hear it which would not be a great marketing slogan for a cable company.
Exactly right, but I would insist on a far more rigorous measure of repeatability than you did. If one person can reliably and repeatably detect a difference, with no possibility of cheating, then there is in fact a difference, and the question of whether or not the cables have an audible difference can be laid to rest. However, from a scientific viewpoint, the single person finding would be far from irrelevant. It alters the entire hypothesis that you need to address. The scientific question that you would have to address is no longer "is there a difference between the cables", because that will have been proven. Say that the one person came from a sample of 10,000. The scientific question that must be addressed is how the person who can detect the difference is different from the other 9,999 people. Is the difference something that can be trained, or is it solely genetic? The answer may well be both.

One of the few auditory phenomena for which the reasons are more or less known is perfect pitch. There are three conditions that have to be met. First, there must be a genetic disposition. Second, there must be active involvement with music. Third, involvement with music must happen during a critical period, at approximately seven years of age. If any of these conditions are not met, perfect pitch won't happen.

So, there are several scientific disciplines involved in the studies that identified the conditions needed to hear perfect pitch. Is there reason to believe that any less would be needed to study individual differences of any auditory phenomena, and the conditions under which they occur?
post #45 of 56
Quote:
Originally Posted by M0T0XGUY View Post
The set-up, I imagine, would measure the frequency response of an amplifier using a few different sets of interconnect cabling.
Hello Motoxguy,
Sorry to disturb your DBT discussion, but I did this some time ago with interconnect cables lended for a double blind test. I did not went through an amplifier, which would add unuseful frequency response problems. I played some reference signals burned on CD in a CD player, connected with various interconnects the analog output to the analog input of a DAT deck, whose digital output was plugged into the computer soundcard (a Marian soundcard with bit exact capture ability on its S/Pdif input).

If you are still interested in the results, I can post the frequency responses.
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