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Post by ChrisB on Jan 27, 2016 22:51:54 GMT
I would contest that my initial experience was equal to, or better than, a blind test (albeit with only two rounds).
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Post by Deleted on Jan 27, 2016 22:57:47 GMT
Philip has a part of it - A/B tests cause a pressure to hear differences, and such quick changes do not work well. You need time for the change to percolate its way through your being until that moment comes when you hear the difference - or not. What's the worst way to listen to music? Among a group of people. Blind tests are no way to relax and enjoy music. They just don't work and, I think, cause the very expectation bias you're trying to avoid. Trust your hearing and your judgement. There's no-one who needs to be convinced or otherwise except you. Lawrence, I am an objectivist like you when it comes to religion and other items of faith. However, music is an emotional experience and you cannot really be an objectivist about it. No scientific instrument is going to tell you whether it's enjoyable or not. Whilst I partly agree, I'm not looking for a scientific test to tell me whether I enjoy / prefer music. Of course the subjective experience is primary. But if you can't reliably tell the difference between sound with the product and without (at least in the short term) then that is a useful bit of information for other forum members to know about. If one is trying to provide members with useful information, then I would have thought it would be worth considering. Faith is all about believing things on bad (or no evidence). It is not justified true belief. In this respect, I think you are asking me to take it on faith that this expensive cd mat makes a difference to the sound quality. You could perhaps remove all of the doubt and remove faith from the equation. If you couldn't reliably tell the difference in a quick A/B test then the difference has by definition to be very small or must take a long time to reveal itself. In which case, what would be the point of my trying the equipment for a short time? |
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Post by Deleted on Jan 27, 2016 22:59:42 GMT
Sorry, I'm still confused - of course, I understand what a placebo is. However, I don't see how your post relates to the experience that I had - first post at the top of this page (not the thread starter), which Martin wrote. I'm not get a link - could you please re-post the link or the part of the thread that you are referring to? |
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Post by ChrisB on Jan 27, 2016 23:03:43 GMT
Sure, here you go..... A quick update - after having spent a little more time with this mat, I've sent it on to Chris. My main reaction is one of confusion that such an apparently simple device can do what it's doing to CD replay. It's not just the simple disc of man made material that it appears to be - OK, I accept that, but what's going on? I don't know and as I said earlier, the fact that I unknowingly used it wrongly with the result of no improvement and then (also unknowingly) used it correctly with a positive result proves to me that this is not an imagined step up in sound quality. It makes a small but pleasant difference to the sound, but for me the asking price is too high to justify it. At half, or a quarter of the price, it would still not do it for me, I'm afraid. I've now got my hands on a John Blue disc, which is very much cheaper and I shall be trying that. |
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Post by Deleted on Jan 27, 2016 23:10:46 GMT
Sure, here you go..... A quick update - after having spent a little more time with this mat, I've sent it on to Chris. My main reaction is one of confusion that such an apparently simple device can do what it's doing to CD replay. It's not just the simple disc of man made material that it appears to be - OK, I accept that, but what's going on? I don't know and as I said earlier, the fact that I unknowingly used it wrongly with the result of no improvement and then (also unknowingly) used it correctly with a positive result proves to me that this is not an imagined step up in sound quality. It makes a small but pleasant difference to the sound, but for me the asking price is too high to justify it. At half, or a quarter of the price, it would still not do it for me, I'm afraid. I've now got my hands on a John Blue disc, which is very much cheaper and I shall be trying that. Are you suggesting that your not hearing any difference until you learned that you were using the mat upside down is equivalent to a blind test? If that's the case then I have to confess to being a bit surprised. Could expectation bias have been triggered by the fact that you had just learned that you needed to turn the mat over for it to work? What I'm asking is that, in this case, you would get someone to play a cd several times both with and without the mat, not telling you each time whether the mat is there or not. If you can reliably tell when the mat is there then I am convinced that it makes a difference. If you can't then I am convinced that it doesn't. I don't understand the hostility to this test TBH. |
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Post by ChrisB on Jan 27, 2016 23:31:35 GMT
No, you stil misunderstand me, I think.
What happened was that the first time I used it, it was used incorrectly and I did not know that. In this case I heard no difference. The second time, I used it correctly and I did not know that. On both occasions I was unaware that there was a right and wrong way to use it. Despite that, on the second time I used it, I heard an improvement. It wasn't until I came to use it for the third time, that I learnt that there was a 'correct' way.
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Post by Tim on Jan 28, 2016 3:02:00 GMT
I suppose it's System system system....... Or, placebo, placebo, placebo.........  |
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Post by MikeMusic on Jan 28, 2016 8:13:58 GMT
Come and see me sometime Tim and you can decide for yourself
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Post by MartinT on Jan 28, 2016 8:15:10 GMT
I don't understand the hostility to this test TBH. I tried to explain it to you here. If you read the more upmarket hi-fi titles (Stereophile, in particular), they explain it further and flat refuse to use blind/double-blind testing because of this. It has nothing to do with placebo and everything to do with the way that we listen to music. I've attended blind tests and you spend all your time worrying about whether you should be hearing differences and not enough time listening for enjoyment. Of course the results are unreliable. That's not how I listen at home! |
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Post by MikeMusic on Jan 28, 2016 8:22:11 GMT
It is also more efficient with time to know what you are doing. I have a benefit when I test as the other half doesn't know what I'm doing Replies range from Preferred the first Second is much better Can't tell any difference Rarely I have 'tested' by changing nothing. She didn't hear any difference  |
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Post by Deleted on Jan 28, 2016 8:36:19 GMT
I don't understand the hostility to this test TBH. I tried to explain it to you here. If you read the more upmarket hi-fi titles (Stereophile, in particular), they explain it further and flat refuse to use blind/double-blind testing because of this. It has nothing to do with placebo and everything to do with the way that we listen to music. I've attended blind tests and you spend all your time worrying about whether you should be hearing differences and not enough time listening for enjoyment. Of course the results are unreliable. That's not how I listen at home! I understand. I'm not saying that blind testing is perfect, it is flawed in the way you explain. But it would add useful information IMO and is not useless. We should treat with caution the reasoning given by a hifi magazine. Magazines have an agenda. They are going to be unlikely to conduct blind test when they reveal that a length of coathanger wire is indistinguishable from an expensive bit of speaker cable in a blind test. That would be the end of their business. You say "trust your ears", but are unwilling to trust them in a blind test. I think there is a contradiction there, but I guess we should probably agree to disagree. It's been an interesting conversation though . Lawrence |
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Post by MartinT on Jan 28, 2016 9:17:55 GMT
A useful measure of whether you're going mad is to use friends to test changes with. I've sat with Mike and John and we've heard differences that are frankly amazing. That's when you know you're not hearing things. I know and trust John and Mike's ears as much as my own. TonyC is also a very good judge of sound, the House MD of system diagnosticians!
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Post by dsjr on Jan 28, 2016 12:53:06 GMT
I do worry that some here have 'collections' of CD mats... Judging by the prices asked for such add-ons, I really think a proper objective test is called for, looking at the digital waveform coming out of popular transport types with mat and without, seeing if there really is a difference and if there is, what can be done either in the DAC receiver or the transport itself to negate the need for such things.
Static was one concern I remember (see if you can buy a used surviving Zerostat, as current ones cost stupid money now). The whole green pen idea seemed to help at the time, but I can't seem to notice any difference thirty years on with discs I have from that period.
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Post by MartinT on Jan 28, 2016 19:24:12 GMT
I only have a 'collection' as I progressed up the chain. I do mean to sell them all off and keep the Ultima. To replicate what the mats do may be tricky as we don't really know if the SQ benefit is mechanical, electromagnetic, electrostatic or some combination of. The website looks like obfuscation (possibly deliberate to prevent copying of the ideas). I can only tell you what I've already said, which is that for a number of years I used the 3-D with good solid benefits in SQ. I then bought the Ultima and couldn't hear any difference from the 3-D. No expectation bias worked here. More recently I've upgraded the sound of my system (the Belles power amp, change of cables, change of supports) and now I could hear that the Ultima is better than the 3-D, just trying it again on a whim. Mike and John heard it, too. You'll have to take that as read and I'm not trying to convince anyone else. However, I am offering out the 3-D for listening tests and ChrisB has independently reported benefits. Now it's with Stratmangler . If anyone else wants to try it, just PM me. It's the only way you'll know for sure. |
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Post by Stratmangler on Jan 29, 2016 11:50:47 GMT
Thanks for the loan of the mat Martin.
As I was primarily interested in hearing if there would be any differences with ripped files (my primary digital source is a Squeezebox Touch/M2Tech Evo DAC combo. Both devices have high quality linear PSUs).
So I ripped a CD in EAC with and without the mat. I ripped to separate WAV files, and included the rip report in the appropriate folder.
And I couldn't hear any difference between the pairs of files, no matter which pairing I used.
I then looked at the rip reports, and all the checksums and percentages were found to be identical.
There was one notable difference - the files ripped with the mat took approximately twice the amount of time to be ripped compared to the files where the mat was not used. That was all.
The ripping was performed by a computer optical drive, and these don't run according to Reed Solomon error recovery. The computer optical drive operates on simple data block comparison.
As a final check I processed one of the tracks with and without mat using a program called Audio Diffmaker.
The program literally compares the data, and it will create a difference waveform.
The result was the track's length of silence, which indicates that there is no difference.
So I then popped the CD into my BluRay player, and did a comparison with and without the mat, and again did not hear any differences between with and without.
The mat doesn't work for me.
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Post by MartinT on Jan 29, 2016 13:23:33 GMT
Thanks for trying it, Chris. I wouldn't expect it to make a difference on rips as the data should be the same unless there are gross reading errors. I hear differences on playback and that is when the data is clocked through in real-time.
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Post by Tim on Jan 29, 2016 14:27:43 GMT
Come and see me sometime Tim and you can decide for yourself Thanks for the offer Mike, but it wouldn't be worth the journey even if I could notice a difference |
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Post by MikeMusic on Feb 6, 2016 17:26:48 GMT
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