Post your links to DBTs here.

[Brett A]

I think it would be helpful to have a thread to list some of the many double blind tests that are referenced here at AH. It seems DBTs make up a good deal of the ground that many arguments are built on in these forums. And I, as a person who’s fairly new and trying to make my way through this stuff, would find it helpful to be able to refer to the specific studies that post their results online. (My Google searches provide mostly arguments for or against DBTs and very few actual tests results.)
Thanks in advance for some solid references.

 

[gus6464]

Here is a good one.
http://www.matrixhifi.com/contenedor_ppec_eng.htm

 

[fmw]

I can't find the link any longer. Stereophile magazine did a nice job with an amplifier bias controlled test between a mid priced solid state and very expensive tube amp. Their process was very similar to the process I use and I consider their findings to be valid. They had approximately a 65-35% result which showed that a meaningful majority of people could hear the difference between the SS and the tube amp.

Tubes amps, as you know, have more harmonic distortion than SS amps and the two subject amps showed an audible difference - truthfully more than I thought they would. I wish they had done it again with two SS amps. The test doesn't appear to be on their site any longer. I mention it because they went to a lot of trouble explaining the details of how they conducted the test and they did it right, in my opinion.

I've read a lot of "blind test" articles that do not show a valid testing method on the internet. It is a fussy, time consuming and exacting process. Not many people do it. There really aren't that many valid bias controlled listening tests performed and I'm not sure the internet is a very good place to look for them. I mentioned the Stereophile test only because it was the best one I had every seen on the internet.

 

[mike c]

http://bruce.coppola.name/audio/Amp_Sound.pdf

didn't know bruce coppola was a mod here
http://bruce.coppola.name/audio/wisdom.html

 

[WmAx]

I can't find the link any longer. Stereophile magazine did a nice job with an amplifier bias controlled test between a mid priced solid state and very expensive tube amp. Their process was very similar to the process I use and I consider their findings to be valid. They had approximately a 65-35% result which showed that a meaningful majority of people could hear the difference between the SS and the tube amp.

Tubes amps, as you know, have more harmonic distortion than SS amps and the two subject amps showed an audible difference - truthfully more than I thought they would. I wish they had done it again with two SS amps. The test doesn't appear to be on their site any longer. I mention it because they went to a lot of trouble explaining the details of how they conducted the test and they did it right, in my opinion.

I've read a lot of "blind test" articles that do not show a valid testing method on the internet. It is a fussy, time consuming and exacting process. Not many people do it. There really aren't that many valid bias controlled listening tests performed and I'm not sure the internet is a very good place to look for them. I mentioned the Stereophile test only because it was the best one I had every seen on the internet.

If this is the test I remember, it was not distortion that caused audible difference, but instead, it was the result of the tube amp having a massive output impedance, thus causing substantial equalization via reactive interaction with the speaker impedance. I seem to remember reviewing the measurements of each amplifier used in this DBT -- if indeed this is the same DBT we are talking about.

-Chris

 

[davidtwotrees]

didn't know bruce coppola was a mod here[/QUOTE] From bruce's site........... "They have tons of good articles on a wide range of audio/video topics. The founders are electrical engineers. They have an active forum where people are willing and able to talk sense about audio, unlike the aptly named Audio Asylum, for instance. My small quibbles aside it's an excellent site. I am a moderator on the forums using the handle "Rip Van Woofer"."

 

[mtrycrafts]

I think it would be helpful to have a thread to list some of the many double blind tests that are referenced here at AH. It seems DBTs make up a good deal of the ground that many arguments are built on in these forums. And I, as a person who’s fairly new and trying to make my way through this stuff, would find it helpful to be able to refer to the specific studies that post their results online. (My Google searches provide mostly arguments for or against DBTs and very few actual tests results.)
Thanks in advance for some solid references.

You'll just have to wait until I get home early next week
Not a lot are on line besides that Spanish link. There is a link to the ABX DBTs but they only give results.

Besides, there is no real arguments against DBT, just like evolution. No disagreement within the real scientific community. DBT IS the Gold Standard be it in audio, medicine, or what have you.

ps: by the way, didn't you keep the links and printed citations that was given not that long ago? Or, am I thinking of someone else who asked for them as this comes up repeatedly.

 

[fmw]

http://bruce.coppola.name/audio/Amp_Sound.pdf

didn't know bruce coppola was a mod here
http://bruce.coppola.name/audio/wisdom.html

That is a classic account of a bias controlled listening test done right. I'm sure the Believers hated it. Glad you posted it.

 

[Alex2507]

Besides, there is no real arguments against DBT, just like evolution..

In order to further prove creationism as a theory my monkey wants to blind fold you ...
"what's that?" ...oh ... he says he wants to tie you up ...

... Ahhh ... never mind, his methodology is flawed ...

Just because he is willing to do sick things to you is no proof that the two of you are not related.

 

[Brett A]

Besides, there is no real arguments against DBT,

That seems to be the consensus here at AH. But when I look around the rest of the audio 'net, they are very much a source of debate. There are believers in earnest on both sides of the argument. I have not set up camp with either one. -still looking into it. These links are helpful and informative. Thanks.

ps: by the way, didn't you keep the links and printed citations that was given not that long ago? Or, am I thinking of someone else who asked for them as this comes up repeatedly.

I don't think so. I've been away from the forum for a while. I can go back in my posting history and look-see if I missed something.

 

[Brett A]

I found this one interesting:

http://www.provide.net/~djcarlst/abx_data.htm

 

[mtrycrafts]

In order to further prove creationism as a theory my monkey wants to blind fold you ...
"what's that?" ...oh ... he says he wants to tie you up ...

... Ahhh ... never mind, his methodology is flawed ...

Just because he is willing to do sick things to you is no proof that the two of you are not related.

Just don't forget, we as humans have an apt capability to do the same to our own and to them.

 

[mtrycrafts]

That seems to be the consensus here at AH. But when I look around the rest of the audio 'net, they are very much a source of debate. There are believers in earnest on both sides of the argument. I have not set up camp with either one. -still looking into it. These links are helpful and informative. Thanks.

Yes, but that debate is not within the audio science world. The same can be said for that other thing I brought up, but still, there is no such debate in the professional science world on either subject

One can also correlate it to other areas: homeopathic meds, psychics, etc.
That is not a debate.
But, there are areas in science where a debate does exist, just don't ask for an example right now Maybe Astrodon can list a few.

 

[mtrycrafts]

I found this one interesting:

http://www.provide.net/~djcarlst/abx_data.htm

Yes, that is the link I was talking about. David Carlstrom has been with that ABX group from the beginning or almost so. They also don't show all the DBT runs that their group has done over the years. In the olden days, their newsletter had something every issue

 

[fmw]

That seems to be the consensus here at AH. But when I look around the rest of the audio 'net, they are very much a source of debate. There are believers in earnest on both sides of the argument. I have not set up camp with either one. -still looking into it. These links are helpful and informative. Thanks.

Yes, but the believers have to disown the scientific method in order to maintain the beliefs. As someone mentioned earlier, there are those that won't accept evolution even though the scientific community is certain that it represents reality.

I keep trying to get believers to do some objective tests for themselves. They simply won't do it. Not much credibility in that. I've done the tests. I know what is audible and what is not. I admit that it is a lot of fuss and bother but, at least, you don't have to rely on what other people tell you. Do a few bias-controlled tests for yourself. Then you will know. Then you can speak from authority rather than from hearsay.

 

[mtrycrafts]

Here you go

Unfortunately some are in print media:

http://www.avsforum.com/avs-vb/showthread.php?t=941184

http://webpages.charter.net/fryguy/Amp_Sound.pdf

http://www.hemagazine.com/node/Dolby_TrueHD_DTS-MA_versus_Uncompressed_PCM

http://www.hometheaterhifi.com/volume_11_4/feature-article-blind-test-power-cords-12-2004.html


Gould, Glenn, "The Grass is Always Greener in the Outtakes," High Fidelity, Aug 75, pg 54-59.

Smith, Thomas H., Peterson, Michael R., and Jackson, Peter O., "Are those Ears Really Golden?(Or only Iron Pyrites," The Audio Amateur, 1/80, pg 34, 36, 38, &32.

Shanefield, Daniel, " The Great Ego Crunchers: Equalized, Double Blind Testing,: Hi-Fidelity, Mar 80, pg 57-61.

Nousaine, Tom "To Tweak, or Not to Tweak?" Stereo Review, Jun 98, pg 79-81.

Greenhill, Larry 'Speaker Cables: Can you Hear the Difference?' Stereo Review, Aug 83, pg 46-51.

Nousaine, Tom 'Wired Wisdom, The Great Chicago Cable Caper,' Sound & Vision(Canada), Sep 95, pg. 73-76.

Gallagher, Mitch '1/4" Cable Roundup,' Keyboard, Apr 99, pg. 44-48.

Tom Nousaine, ' The Great Debate: Is Anyone Winning?' Proceedings of the AES, 8th International Conference, 1990.

Masters, Ian G. 'Audiolab Test: Six Power Amplifiers,' Audio Scene Canada, May 1977, pg 44-50.

Masters, Ian G. ' Audiolab Test: Amplifiers and Speaker Cables,' Audio Scene Canada, Jun 1981, pg 24-27.

Masters, Ian G. 'Do All Amplifiers Sound the Same?' Stereo Review, Jan 1987, pg 78-84.

Carlstrom, D., Kruger, A., & Greenhill, L. ' Some Amplifiers Do Sound Different,' The Audio Amateur, 3/1982, pg 30, 31

Greenhill, L. & Clark, D. 'Equipment Profile,' Audio, Apr 1985, pg 56-60, 82-97.

Masters, Ian G 'Do All CD Players Sound the Same?' Stereo review, Jan 1986, pg 50-57.

Pohlmann, Ken C. '6 Top CD Players: Can You Hear the Difference?' Stereo Review, Dec 1988, pg 76-84.

Pohlmann, Ken C. 'The New CD Players: Can You Hear the Difference?' Stereo Review, Oct 1990, pg 60-67.

CD Player Comparison, The Sensible Sound, # 75, Jun/Jul 1999.

CD Player Comparison, The Sensible Sound, # 74, Apr/May 1999.

 

[zhimbo]

That seems to be the consensus here at AH. But when I look around the rest of the audio 'net, they are very much a source of debate.

You can certainly do poorly administered DB tests, and people do overly generalize from single, narrowly constructed tests. There is room for legitimate controversy in these sorts of particulars.

Unfortunately, a certain crowd takes that to mean that the fundamental principles of "testing" itself are meaningless -- at least when it goes against their preexisting beliefs.

 

[zhimbo]

This would be a great sticky thread.

Would it not?

 

[Brett A]

I keep trying to get believers to do some objective tests for themselves... I admit that it is a lot of fuss and bother but, at least, you don't have to rely on what other people tell you.

This is a great idea. I think it would be generally helpful if an "ABX/DBT set-up for dummies" existed somewhere.

(I admit I have not read every article linked to so far in this thread, so if there's one, forgive me.)

Thanks to everyone for the material so far.

 

[fmw]

This is a great idea. I think it would be generally helpful if an "ABX/DBT set-up for dummies" existed somewhere.

(I admit I have not read every article linked to so far in this thread, so if there's one, forgive me.)

Thanks to everyone for the material so far.

I'll write one and post one if someone will use it and actually do some tests. I've worked out a method that is scientifically valid and doesn't require comparators. It does require at least two people.