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Successful ABX of 88.2 kHz vs 44.1 kHz

Someone just posted ABX results on reddit, that shows they were able to successfully ABX an 88.2 files against the same file converted to 44.1.

I have yet to hear of any "hi-res" music passing an ABX test against it's CD Quality countrpart.

Here's a link to the post:

https://www.reddit.com/r/headphones/comment...s_out_a/cuv8866

I don't understand how this is even possible.

Successful ABX of 88.2 kHz vs 44.1 kHz

Reply #1
He said he downsampled with Gold Wave ... have a look at the two entries for it profiled on http://src.infinitewave.ca/. One version is OK, but the other, older one... tons of aliasing, probably audible.

Successful ABX of 88.2 kHz vs 44.1 kHz

Reply #2
Also unfortunately foo_abx can't currently be used to reliably ABX files that have different sample rates. The delay when switching from sample A to X is longer if X doesn't have the same sample rate so track identities are revealed by accident.

Until this problem is fixed the user should upsample the new file back to the original samplerate when ABXing the difference.

Successful ABX of 88.2 kHz vs 44.1 kHz

Reply #3
Another thing worth to point out is the test is done using ASIO. Without any SRC in the DSP chain the playback device need to switch its clock when playback at different sample rates. The switching process can make a noticeable delay and even a click/pop noise.

Moreover, the playback device can actually perform differently in different sample rates therefore the result is device-dependent rather than the format itself.

Also, intersample peaks in the source file can result in clipping after resampling, so it is a good idea to reduce about 2-3dB while testing unless the source file is already quiet enough to avoid intersample peaks.

Assume there is no deliberate cheating, the more appropriate way to perform the test is use replaygain to reduce the volume of both files and use a DSP resampler like the SoX plugin to upsample the 44.1k file to 88.2k again to avoid switching noise or delay while testing, and avoid device-dependent sound quality differences as well.

Successful ABX of 88.2 kHz vs 44.1 kHz

Reply #4
I'm not a professional or anything, I just know what I like and generally prefer HD audio vs the standard.  It's possible that the mastering is different in many HD releases and that's why I prefer them, but I'm not certain.  I will say that I've ABX'ed 24 and 16 bit audio and couldn't tell a difference, getting a whopping 9/16 attempts correct, but i do hear something different between sufficiently different samplerates.  It's quite possible that downsampling in goldwave produced audible artifacts on its own, but this was just something I did for the fun of it about a month or so ago.  I'm not trying to say I've got magic ears or anything, but I do often hear a difference, even if I can't pinpoint it other than to simply say that it sounds 'better'.

Edit:
The track was resampled using Goldwave 6.13

Successful ABX of 88.2 kHz vs 44.1 kHz

Reply #5
>  I do often hear a difference, even if I can't pinpoint it other than to simply say that it sounds 'better'.

And that's why we've got ABX.

Successful ABX of 88.2 kHz vs 44.1 kHz

Reply #6
Am I correct in understanding the actual files he used haven't been posted anywhere for others to download, evaluate, and attempt to ABX themselves?


Successful ABX of 88.2 kHz vs 44.1 kHz

Reply #8
Provided solely for the purposes of research and critique: https://mega.nz/#!PMp1nS6A!jvyTUhhE...zfCGeJE4eg3Dojg


Just to let you know, I didn't post this here to call you out.  It's just that these guys know WAY MORE about this stuff than I do.

I spent weeks ABXing 24/96 vs downsampled 16/44.1 and couldn't tell a difference on about 2 dozen tracks.  I had to stop because my wife was getting sick of seeing me on headphones all the time.

So, I was curious what could be the cause of your golden ears.  I'm still planning to ABX the files you send me on Reddit yesterday when I have a 15 minute break during the day.

Successful ABX of 88.2 kHz vs 44.1 kHz

Reply #9
A general ABX question.  All ABX shows you is that you can tell the difference between 2 files.  It doesn't actually tell you which one you like better.

So it may be possible that you subjectively likes a high res or a FLAC file better than it's low-res/lossless counterpart.

But if you successfully can distinguish two files via ABX, it would be nice if the tool let you blindly listen to clips from the track and pick which one you think you like better.


I'm also gathering from this thread, that it's really not possible to properly ABX a high res file against a standard 44.1/16 FLAC due to limitations of foobar2000 and foo_abx plugin?  Is that correct?

Successful ABX of 88.2 kHz vs 44.1 kHz

Reply #10
But if you successfully can distinguish two files via ABX, it would be nice if the tool let you blindly listen to clips from the track and pick which one you think you like better.

ABX has the specific goal of establishing if there is/is not an audible difference. If what you want is to determine a preference then that is a completely different tool, ABC/HR.

Obviously if you fail to hear a difference with ABX then there is no need to use ABC/HR.

Successful ABX of 88.2 kHz vs 44.1 kHz

Reply #11
But if you successfully can distinguish two files via ABX, it would be nice if the tool let you blindly listen to clips from the track and pick which one you think you like better.

ABX has the specific goal of establishing if there is/is not an audible difference. If what you want is to determine a preference then that is a completely different tool, ABC/HR.

Obviously if you fail to hear a difference with ABX then there is no need to use ABC/HR.


Is there an ABC plugin for foobar2000?  I would love to ABC different remasters of some older albums.

Successful ABX of 88.2 kHz vs 44.1 kHz

Reply #12
This is in reply to your previous post.

In post #3, Case already addressed the other question. Yes it is possible and it's a bit of a stretch to call upsampling the lower res track improper, unless you use a junky SRC.  I'd probably not use Gold Wave just to be on the safe side.
Is 24-bit/192kHz good enough for your lo-fi vinyl, or do you need 32/384?

Successful ABX of 88.2 kHz vs 44.1 kHz

Reply #13
It seems that jdeberhart's 44.1k file is properly resampled. There are only very few possibly clipped samples in the 44.1k version, other than that it generally nulled with the 88.2k version down to -140dB up to 20kHz when I upsampled it to 88.2k again using the SoX plugin.

Then the main problem left is the delay when switching sample rates. This video clearly demonstrates how to exploit the delay to know the correct answer, and how a DSP resampler can eliminate this delay.

https://youtu.be/H6aRV3ZZWiE

Download the SoX resampler plugin here:
https://www.hydrogenaud.io/forums/index.php...ost&id=7331

Successful ABX of 88.2 kHz vs 44.1 kHz

Reply #14
I don't know that it rules out the possibility of samplerate-specific hardware coloration.
Is 24-bit/192kHz good enough for your lo-fi vinyl, or do you need 32/384?

Successful ABX of 88.2 kHz vs 44.1 kHz

Reply #15
Just lately we had a member abxed positive his behringer DAC with 88.2->44.1 but not back to 88.2.
I don't know how the Valhalla tubes in the playback chain poduce IM with and without hf content.
Also i don't take any abx of high against low samplerates with foobar to serious anymore because cheating is so easy with even a bad spectral analyser running at the desktop. Tis may of course only show how much of a badbass me is.
Is troll-adiposity coming from feederism?
With 24bit music you can listen to silence much louder!

Successful ABX of 88.2 kHz vs 44.1 kHz

Reply #16
I'm a little concerned that we're coming up with excuses why this test passed, when we feel it should not have passed.

If there are specific steps that the community here feels are needed to be followed, in order to properly ABX hi-resolution music vs CD Quality, I'm thinking we need to document them somewhere (perhaps the Wiki) and justify the sh** out of why we require this, or the Stereophile Magazine guys will have a field day with us.

Successful ABX of 88.2 kHz vs 44.1 kHz

Reply #17
My apologies for violating TOS #6 with the title.  Thank you to whatever mod fixed my oversight.

 

Successful ABX of 88.2 kHz vs 44.1 kHz

Reply #18
I'm a little concerned that we're coming up with excuses why this test passed, when we feel it should not have passed.

meh

Stereophile Magazine guys will have a field day with us.

meh

Explaining the pitfalls of homebrew testing is fine, but trying to explain what constitutes good science to those who pretend to embrace it only when it suits their agenda?
Is 24-bit/192kHz good enough for your lo-fi vinyl, or do you need 32/384?

Successful ABX of 88.2 kHz vs 44.1 kHz

Reply #19
I'm a little concerned that we're coming up with excuses why this test passed, when we feel it should not have passed.

meh

Stereophile Magazine guys will have a field day with us.

meh

Explaining the pitfalls of homebrew testing is fine, but trying to explain what constitutes good science to those who pretend to embrace it only when it suits their agenda?


I don't want to give those guys any talking points against people that get it.  I guess I'm just cynical that way.

Successful ABX of 88.2 kHz vs 44.1 kHz

Reply #20
You're not cynical enough, I'm afraid.
Is 24-bit/192kHz good enough for your lo-fi vinyl, or do you need 32/384?

Successful ABX of 88.2 kHz vs 44.1 kHz

Reply #21
I'm a little concerned that we're coming up with excuses why this test passed, when we feel it should not have passed.

If there are specific steps that the community here feels are needed to be followed, in order to properly ABX hi-resolution music vs CD Quality, I'm thinking we need to document them somewhere (perhaps the Wiki) and justify the sh** out of why we require this, or the Stereophile Magazine guys will have a field day with us.

We have seen far too many false positives reported over the years to take anything for granted.

It's not as though the regulars here haven't tried to ABX high sample rate vs. 44.1, just that none have reported success, and a lot of these folks are extremely good at detecting small differences. They are also very good at understanding the pitfalls inherent in properly performing such a test.

Successful ABX of 88.2 kHz vs 44.1 kHz

Reply #22
It seems that jdeberhart's 44.1k file is properly resampled. There are only very few possibly clipped samples in the 44.1k version, other than that it generally nulled with the 88.2k version down to -140dB up to 20kHz when I upsampled it to 88.2k again using the SoX plugin.
-140dB is well below the capabities of 16-bit which jdeberhart says is transparent to him, so at this point it should be clear to him that something else is going on.  I'm giving him the benefit of the doubt that he isn't cheating.
Is 24-bit/192kHz good enough for your lo-fi vinyl, or do you need 32/384?

Successful ABX of 88.2 kHz vs 44.1 kHz

Reply #23
this

The log says foo_dsd_asio as output. Does this mean your PCM files are converted to DSD before being sent to your DAC? That would be another variable that could cause audible differences between different sampling rates.


And could you please run one of these high frequency impulses at normal listening volume and tell us if you hear anything, jdeberhart?
test files
"I hear it when I see it."

Successful ABX of 88.2 kHz vs 44.1 kHz

Reply #24
I tried the impulse test and couldn't hear anything.  I'll try ABXing the 44.1 upsampled back to 88.2 this weekend when I've had some rest, though an initial listen isn't promising, leading me to think that there's some sort of samplerate-specific filtering going on in the DAC, which given that it's an ES9018K2M is quite possible.

I'm using the DSD output only for DSD files though, PCM is not converted and instead played back 'native', though the 9018 is still a sigma-delta DAC so ultimately everything is getting converted anyway.

 
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