Converter loop-back tests

[mep]

Ron-Assuming that Amir's findings are correct and I have no reason to believe they aren't, there are only two possible explanations. Either Ethan didn't label each recording correctly or Ethan altered the files to change the dynamic range. The amount of difference between the dynamic range for each recording is so drastic that generational losses wouldn't have caused it so my guess is the ‘test’ was intentionally cooked.

If people truly want to know what generational losses do or don't sound like in the real world, Bruce would be one of the most qualified people on this forum to set up such a test. And I personally don't think a loop back test where you are constantly converting analog back to digital and then digital back to analog is meaningful. A more real world test IMO would be to take a master tape and convert it to digital (which is done every day in the real world) and see if people could detect the difference. Once the tape has been converted to digital and copies of the digital file are made in the native format, I don’t think we should expect to see differences among the digital files unless a different converter was used for each pass.

 

[opus111]

File name: Min/Max RMS Power: Difference
Original: focusrite_b.wav: -56 db/-7 db: 49 db
1 generation: focusrite_d.wav: -92 db/-7 db: 85 db
5 generations: focusrite_a.wav: -87 db/-7 db: 80 db
10 generations: focusrite_c.wav: -83 db/-7 db: 77 db

This is all very interesting but track b here doesn't correspond with what I saw in Audacity. I identified b as the original by eyeballing the noise floor - it showed me digital silence between the two musical segments. The others look about right, I recall about 3dB difference in noise floor between 5th and 10th generation.

 

[MylesBAstor]

I took the test but was not interested . Why are you interested Ron?


Curiosity, sure. But interest? In what way an audiophile runs into generational loss in digital audio? What audio purchase decision changes because of it?


Strawman? It was simply tit for tat. He says if someone doesn't take the test they are afraid of the outcome. I say since he has all the means *and motivation* for blind test yet he does not conduct any in the field of acoustics, he is worse off than others here. Let me ask you this. You say you are interested in generational audio tests. What is your interest level relative to that when it comes to acoustic products? Less or more? Do you think Ethan can help us more or less with that question than this one?

On whose behalf Ron? Mine? Remember, I took the test. You did not by the way . I have no fear of any discussion. But I am really, really tired of the two camps fighting for the sake of fighting. I can tell that is all it is when no technical information is shared. And that is what we have here.

In the last few months I have been deeply studying listening tests of acoustic science. I have tried to discuss the same elsewhere. All the people who fight for listening tests in every chance they get, have been fighting me tooth and nail as to relevance of listening tests there. They much rather go by gut feeling and measurements all of a sudden than performing listening tests. So my request of Ethan is not a random one especially when he was present in the other discussion. I have asked him the same before and as here, he puts forward that incorrect answer that just because there are differences, blind tests are not necessary. That makes no sense to me. Either you believe there is a need for such removal of bias or there isn't. Ethan says the room is more important than anything else. How many blind tests of room acoustic products do you think I can find in his book, forum discussions or other?

Back to the what I have been doing, I can tell you that what I have learned is 1000 times more interesting and relevant to sound in our room than this test. You want to completely change your outlook on audio, study what I have been doing. I wrote an article for WSR magazine in the last issue which I will be posting soon on that topic relevant to true dynamic range of our room using that science. I just finished another one for 20th anniversary of WSR magazine that goes into far more depth on how psychoacoustics and listening tests turn upside down much of what we think we know about acoustics in our rooms. This is why I didn't jump and run around to find a test clip for this test. There are much more useful things we could spend our time on than to run a public test to poke the finger in people's eyes who have gotten a test wrong. I for one am not in favor of public hanging of the forum members in that regard. I rather we all work collectively to learn something new. In the words of the Chuckie (Ben Affleck) in my favorite movie Good Will Hunting: I may not know much, but I know this."

Amir, what is WSR?

 

[JackD201]

Wide Screen Review?

Ethan used testimonials as part of his package of proof.

 

[MylesBAstor]

Wide Screen Review?

Ethan used testimonials as part of his package of proof.

Oh OK, should have known

 

[mep]

Ethan used testimonials as part of his package of proof.

Which is why I threw in the comment about Shakti Stones and posted a link to their "testimonials." I thought his comment about having "testimonials" was a real hoot too. Somehow I don't think Ethan would buy or believe in Shakti Stones because they had "testimonials" from their customers.

 

[JackD201]

I have nothing against testimonials per se but found this amusingly ironic. LOL.

 

[Ethan Winer]

I did not "cook" the files, so I'll let you guys sort out why Amir's [whatever] doesn't match his expected [whatever]. I have the DAW project here, and all the files including the in-betweens. Anyone here is most welcome to visit me to inspect the files and my setup.

--Ethan

 

[Randy Bessinger]

I read through the posts and only need to post that Ron Party seems to me to be totally logical in his replies. I can't say that for many of the rest. Of course, it could be because I am biased and like the same music as Ron