Converter loop-back tests

Indeed, this test will put a lot of these "arguments" to bed permanently.

Ethan...surely you know better than that! :)

Tim
 
I'm not exactly sure how other music will help. The process should degrade any music the same.

That's what I figured too. I suppose if the music were noticeably distorted, or had a severe lack of low or high frequencies, people could rightly claim that further changes due to conversion would be too small in comparison. But both of those tracks are at least decent quality.

--Ethan
 
Ethan...surely you know better than that! :)

Yes, and this is just so pathetic. The people who are the loudest and most belligerent nay-sayers are always the ones who refuse to go on record stating their opinions. They (Mike Levigne) loudly proclaim that even one generation of any "digital" device robs the very life out of any music, but when you ask them (Bruce B) to identify an original track and a copy (or ten), they never post. Instead they (microstrip) insult you for even trying to get to the truth, and make up every excuse for why they won't participate. This tells me that 1) some people really do prefer to believe in magic, and 2) some people refuse to change their opinions even when faced with proof that their opinions are wrong. Why is this? I guess it's a question more for psychologists than audio engineers. :confused:

It seems that even without doing a second test I have my answer!

--Ethan
 
Yes, and this is just so pathetic. The people who are the loudest and most belligerent nay-sayers are always the ones who refuse to go on record stating their opinions.
Say what? Some of us ran the test. What did we get in return? "Oh, I am not going to tell anyone the results." Now you expect us to help you create another thread where if you don't like how the process is going leads to withholding the results again?

They (Mike Levigne) loudly proclaim that even one generation of any "digital" device robs the very life out of any music, but when you ask them (Bruce B) to identify an original track and a copy (or ten), they never post.

Instead they (microstrip) insult you for even trying to get to the truth, and make up every excuse for why they won't participate.
Per above, we did. Your job in running such tests is to be neutral. The only reason to not be so is because you have already predicted how we would vote. If so, then you don't need us to vote. If you have not, then your inclination for one set of outcomes sets up for a corrupt test.

This tells me that 1) some people really do prefer to believe in magic, and 2) some people refuse to change their opinions even when faced with proof that their opinions are wrong. Why is this? I guess it's a question more for psychologists than audio engineers. :confused:
What are talking about Ethan? People are playing these clips casually on their computers. No one is burning CDs and playing them on their systems to satisfy an online test. You are not getting scientific results this way of what you set out to test.

If you care about discovery and learning of the science, then you would need to spend time figuring out what clips are revealing of such differences. To do that you need to understand the technology under test. Giving us two random clips that show no attention to this point says you do not care about the science here. You would be laughed out of the room if you claimed to find differences between two MP3 encoders with some clips you happen to have on your computer. You are expected to know which clips show up the difference more than others and use them to test for differences. Yet when it comes to testing for other things like DAC people seem to think the distortion is apparent in all clips in exactly the same way. Such is not the case with non-linear distortion and generational losses. Despite all of these issues some of us took the test. The conclusion is that some people must have gotten it right or you would already be posting the results showing how everyone voted wrong.

It seems that even without doing a second test I have my answer!

--Ethan
As do I. You are looking for headlines not search for audio truth. Why did you try the test here Ethan? Why not another more popular forum where you would get more votes and give you more "statistically valid" results? Despite that per above some of us did take the test. We are not afraid to be wrong. Yet you declare that we are? Because we don't try to do your homework by picking better test clips?

You say you know this science. Walk us through under what circumstances/clips differences would be heard. If you claim it never can regardless of clips and listening ability, let's hear you say that and prove it. That would be a useful discussion than this odd back and forth of using negative logic to prove something and slapping us in the face for going along...
 
Say what? Some of us ran the test. What did we get in return? "Oh, I am not going to tell anyone the results."

As I already stated, the only reason I didn't reveal the answers (yet) is because I wanted more replies. Especially from Bruce B since he claims he can hear even one pass from the best converters made.

Your job in running such tests is to be neutral.

I am 100 percent neutral. So many people make so many claims, a poll like this is a great way to put those claims to the test. Don't people want to know if their beliefs are valid?

If you care about discovery and learning of the science, then you would need to spend time figuring out what clips are revealing of such differences.

I don't see why that matters. Sure, I could probably concoct some special files that play various test tones to reveal the degradation. Maybe two nearby HF tones that would better reveal soft IMD. But why do that? If the claim is to be able to hear even one pass on "music," then any normal "music" should be acceptable, no?

You are looking for headlines not search for audio truth.

No, I'm looking only for the truth. Apparently many are not! :D

Why did you try the test here Ethan?

Because Bruce B said he can hear even one pass on his high-end converters. I'm not saying he can't! But if he really can, he shouldn't be afraid to chime in on my little test. And if he is afraid, then that says far more than all his previous claims.

We are not afraid to be wrong. Yet you declare that we are?

To your credit, you and a few others were not afraid to be wrong! But clearly some people here are afraid of that.

Walk us through under what circumstances/clips differences would be heard. If you claim it never can regardless of clips and listening ability, let's hear you say that and prove it.

I made no claims at all! All I asked is for people to state if they can really hear the degradation of a few converter passes. Others have made claims. I've been totally neutral all along. If you think I've made claims, or have not been neutral, please show me an example.

--Ethan
 
I know ny opinion does not mean anything. The problem is I can get equal sound from my table radio. I just can't get any impression fron short clips of music.

What kind of sound quality are others getting? Are you listetning to headphones over a computer as I am? Are you listeningr hi quality headphones/ Is there some way to play it over your Stereo?
 
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You guys are getting all excited over nothing. Ethan, the people you want most to take the test are not going to be able to figure anything out from the accuracy or inaccuracy of the rankings of the first set of samples unless Amir tells them how, and they're not going to take the test anyway. They're going to listen to the samples, if they have the technological ability to play them back through a hifi system, come face to face with the very real possibility of looking foolish and keep their heads down. As long as Amir doesn't reveal what to listen for, your next test is every bit as safe as your first one. I doubt anyone else knows what to listen for.

Amir, can you promise to keep your secrets to yourself? If yes, then pubilish the results of the first round, Ethan.

Tim
 
I am 100 percent neutral.
lol.

How could that possibly be? By any defintion of neutrality. Your challenge to Bruce alone shows bias. You have alreaady taken a position on the issue and this is your second attempt at proving your point. By any definition of objectivity you would be barred from either constructing or taking the test.
 
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Say what? Some of us ran the test. What did we get in return? "Oh, I am not going to tell anyone the results." Now you expect us to help you create another thread where if you don't like how the process is going leads to withholding the results again?]
Wasn't it at Micro's suggestion that Ethan run the test again with a different piece of music? I didn't think it was Ethan who "d[id] not like how the process is going". Now, having stated that, what if Ethan simply delays (instead of foregoes) posting the true order until the other test is performed by at least *some of us*? Would that be satisfactory?

What are talking [sic] about Ethan? People are playing these clips casually on their computers. No one is burning CDs and playing them on their systems to satisfy an online test. You are not getting scientific results this way of what you set out to test.
Members, of course, could burn CDs.

Why did you try the test here Ethan? Why not another more popular forum where you would get more votes and give you more "statistically valid" results?
Which forum? AVS, with such luminaries as diomania and hdnewbie?:) Generally speaking they are not the ones claiming to possess this kind of discriminatory hearing ability.

Despite that per above some of us did take the test. We are not afraid to be wrong.
Some are not. But categorically as you state? This is to state nothing of the fact that, as we both know, at least one member decided to not even take the test but, instead, *read* the difference in the clips.

This concept of a generational loss test reminds me of the time here at WBF before Sean Olive and the other folks at Harman made available for public consumption that downloadable program with the dozen or so distortion tests. I remember asking the WBF membership at the time how many were going to download the program and take the test and, IIRC, I got about 3 or 4 positive replies.

Now, having stated that, Ethan, this time I think you stepped over the line in calling out specific members. This isn't a game of gotcha.

You say you know this science. Walk us through under what circumstances/clips differences would be heard. If you claim it never can regardless of clips and listening ability, let's hear you say that and prove it.
Strawman. Tim, I agree.
 
Which Forum? Hydrogen Audio.

I have published various examples of distortion I think in the thread" what to look for in anplifiers." Only Tomolex seemed interested.


BTW you have already corrupted the test by telling AMIR he is wrong.
 
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The more people that chime in, the more statistically significant the results will be.

How statistically significant do you think that would be? Have you controlled for the fact that people are listening to your clips on computer speakers? Even if there was a difference in the clips, the results would be skewed towards the null hypothesis by the large number of people here attempting to listen to your clips on speakers which do not have the resolution to demonstrate the difference. You did not even make an attempt to ask people to take care to listen to the clips in a controlled fashion. Neither did you ask people to indicate what they were using to play back those files. Nor did you ask how many times people listened to your clip, or whether there were other distractions at the time. Did you not think about this?

This little experiment you are doing is going to be a complete waste of time statistically (and needless to say, scientifically). This case is instructive of how a poorly conducted blind test always confirms the null hypothesis, because I assure you - the null hypothesis will be proven, regardless of whether there is actually a difference in the clips or not. Who knows what you will do with the result then? Would you publicize it and say that there is no difference in sound quality in ten feedback loops, and that even audiophiles in an audio forum including (insert prominent audiophile's name here) could not detect it?

The fact that you then go on and make a little spray at some people for not participating makes one suspect you are only doing it to get back at your forum enemies. If you are interested in science, then do science. Instead, you come across as an idealogue with an agenda. Really, it is very unpleasant to watch. When was the last time one of those people named in your post started a thread with the explicit objective of denigrating you?

Here is another data point for you: I listened to those clips. I could barely hear a difference. So you can mark me down as a = b = c = d.
 
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just for the record, I didn't listen through computer speakers. I listened through very good Sennheiser headphones. I would think lots of people here have that capability in their systems, or, if not, the capability of burning a cd. Just sayin'...

Tim
 
Just to inform members that I deleted all my posts in this thread. If the thread starter feels offended by comments about the subjective musical quality and the recording quality of the tracks I do not feel good participating in it.
 
How statistically significant do you think that would be? Have you controlled for the fact that people are listening to your clips on computer speakers? Even if there was a difference in the clips, the results would be skewed towards the null hypothesis by the large number of people here attempting to listen to your clips on speakers which do not have the resolution to demonstrate the difference. You did not even make an attempt to ask people to take care to listen to the clips in a controlled fashion. Neither did you ask people to indicate what they were using to play back those files. Nor did you ask how many times people listened to your clip, or whether there were other distractions at the time. Did you not think about this?

This little experiment you are doing is going to be a complete waste of time statistically (and needless to say, scientifically). This case is instructive of how a poorly conducted blind test always confirms the null hypothesis, because I assure you - the null hypothesis will be proven, regardless of whether there is actually a difference in the clips or not. Who knows what you will do with the result then? Would you publicize it and say that there is no difference in sound quality in ten feedback loops, and that even audiophiles in an audio forum including (insert prominent audiophile's name here) could not detect it?

The fact that you then go on and make a little spray at some people for not participating makes one suspect you are only doing it to get back at your forum enemies. If you are interested in science, then do science. Instead, you come across as an idealogue with an agenda. Really, it is very unpleasant to watch. When was the last time one of those people named in your post started a thread with the explicit objective of denigrating you?

Here is another data point for you: I listened to those clips. I could barely hear a difference. So you can mark me down as a = b = c = d.

well stated Keith. Like you I felt very uncomfortable watching Ethan work some pseudoscience and then denigrate members here to the point that micro removed his posts. Needless to say Ethan has an agenda and I think you hit the nail right on by naming his agenda.
 
Burning a CD would add another layer. I don't have a dog in this fight. My issue is with the first generation CD.
 
I don't know what happened to the original post, but Ethan's you tube video is excellent, I would recommend that anybody on either side of the religious arguments would enjoy it.

http://www.youtube.com/watch?v=BYTlN6wjcvQ
 
I just can't get any impression forn short clips of music.

Then tell me the minimum length you require and I'll make an excerpt that long so you'll be able to participate without any reluctance.

Are you listetning to headphones over a computer as I am? Are you listeningr hi quality headphones/ Is there some way to play it over your Stereo?

Why would you not listen using the highest quality playback available? Do you not have a way to play Wave files through your good system? You do know how to burn a CD, yes?

--Ethan
 
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