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Is 22kHz brickwall cut off audible? - Listening test

Can you hear a difference between the files

  • I can hear a difference and I have an ABX result

    Votes: 2 11.8%
  • I can hear a difference but have no ABX result

    Votes: 3 17.6%
  • I cannot hear a difference and I have an ABX result

    Votes: 3 17.6%
  • I cannot hear a difference but have no ABX result

    Votes: 9 52.9%

  • Total voters
    17

pkane

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sub sample timing errors will only give a real difference at high frequencies.. What I heard was a difference with the full spectrum. maybe there is also a gain error?

Here's the difference spectrum of Pavel's two files aligned to 1 sample:
1657558271884.png



And here are the same two files with sub-sample alignment:
1657558320095.png
 

fieldcar

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So, how could this be audible given what we've found? Playback device distortion? A potentially permanent low pass filter in his equipment causing phase shifts?
 

Jimbob54

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So, how could this be audible given what we've found? Playback device distortion? A potentially permanent low pass filter in his equipment causing phase shifts?
Only one person has declared they can hear a difference so far . I'm assuming that's the OP. I might try tonight but I'm not hopeful based on my past poor attempts at abx.
 

pkane

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Question: Is this also the case when a single digital file is used ?
This sure will be the case when 2 recorded files are nulled from separate recordings (the clocks will drift).
In this case only one file is recorded and the second one is the same file but filtered there should be no clock drift.

Clock drift correction and subsample alignment are two different processes in DeltaWave. Both are required when using independently clocked DAC and ADC.

Even with an all-digital filtering, it's possible to have fractional sample delays, depending on the filter type and number of taps (for FIR).
 

levimax

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I just did a diff between the two tracks: clearly audible difference in the full audio band...(even distorted) There must be something wrong with your way of filtering..

The diff:
View attachment 217732
I don't have time to do full test now but I do have them loaded in Foobar ABX and on practice I am able to identify. I don't understand why these files are so distorted.... it isn't subtle it sounds like 10% to 20% or more distortion.... were the tracks like this to start or did the filtering ruin them? For those not trying ABX because of "high frequency hearing loss" please don't let that stop you as I don't think it matters.
 
OP
pma

pma

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Sample alignment is insufficient for a proper difference file. The error in the result can be very large if you don't align to a tiny fraction of a sample.
Exactly. Your Deltawave makes an excellent job in this.
 

fieldcar

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@pma

Pardon my snarky post earlier. You've always given me the impression you're far from an audiophool, but I'm still curious. I'd like to know how you suspect you can hear the difference.

The only time's I've triumphed the impossible as it pertains to having semi-Godlike hearing is the flaw's in my earstudio ES100's SBC implementation, and being able to tell how lossy codec's even at 300+Kbps can't perfectly handle chimes. I haven't really expressed any of these ideas on ASR, as it's an uphill battle, but maybe I should.
 
OP
pma

pma

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So, how could this be audible given what we've found? Playback device distortion? A potentially permanent low pass filter in his equipment causing phase shifts?
Good question :). Playback device is Topping D10s and it works excellent. The headamp is my own and works like this:

headamp_thd.png


Other measurements correspond with this one, there are no flaws.

Headphones used were Koss Porta Pro for ABX report1 and Sennheiser HD598 for report #2.

If we cease usual secondary school simplifications, my humble question is - what do we really know about hearing?

To those who might be interested, there is a link that summarizes results of hundreds of participants of similar tests

 

Hayabusa

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Exactly. Your Deltawave makes an excellent job in this.
Does deltawave constantly adjust phase to match,? If so this is not the way to do it for two digital files with the same reference clock. It should find the subsample delay for the whole file and apply the same shift to each sample
 
Last edited:

fieldcar

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So. What do you hear / what were the 'tells'?

With the ES100 using the SBC codec, I heard potentially jitter with clean tones in the music. Almost like a repeating crackle similar to a poor connection with a 3.5mm jack. Once I switched to Apt-X/HD/LDAC, the noise went away. Is that the banded coding's edges showing? Would a FR sweep show this flaw? Not sure. Amir's SBC measurements look pretty great with topping's bluetooth products.

With the flaw in the 320Kbit MP3 and chimes, it was a muddying sound to the rolling crystal-like chimes in the 6-10KHz region. I tried MP3, Apple's AAC, Opus, and they all had similar issues with the air/presence region, but only during a short part of a song, and if I wasn't paying much attention, there would be no way I'd care about the flaw unless I was listening for it.
 

Blumlein 88

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Does deltawave constantly adjust phase to match,? If so this is not the way to do it for two digital files with the same reference click. It shoulf vind the subsample delay for the White file snd apply the same shift to each sample
By default it does not, but you can have it do so if you wish. In this case according to Deltawave there is no difference in phase until the filter kicks in above the 20 khz range.

If you place a low pass filter at 15 khz, taking out the difference the filtering leaves at the higher end, PK metric is -142.7 db, and Difference RMS is a touch over -120 db. Hard to see how this is audible. Wish I knew what PMA is hearing.
 
Last edited:

voodooless

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Good question :).
Maybee record the output of the tracks with the headphones at 96 kHz and then do the Deltawave compare again? Sadly this will not be easy to do cleanly as with the pure recordings, but it might yield some additional effect of the headphones in the audible spectrum?

Tried it on speakers as well?
 

BDWoody

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Good question :). Playback device is Topping D10s and it works excellent. The headamp is my own and works like this:

View attachment 217778

Other measurements correspond with this one, there are no flaws.

Headphones used were Koss Porta Pro for ABX report1 and Sennheiser HD598 for report #2.

If we cease usual secondary school simplifications, my humble question is - what do we really know about hearing?

To those who might be interested, there is a link that summarizes results of hundreds of participants of similar tests


I thought we had someone go through this a while back...

 

pkane

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Does deltawave constantly adjust phase to match,? If so this is not the way to do it for two digital files with the same reference clock. It should find the subsample delay for the whole file and apply the same shift to each sample

That's how it works. You can chose to use sample-only alignment, sub-sample alignment, and/or clock drift-correction. The result will be based on the settings.
1657570049671.png


Even variable group delay can be removed by DeltaWave, but that's a more advanced function in the Non-Linear calibration settings.
 

bennetng

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I don't think the use of poor sounding vinyl rip is an issue, especially if it is the one and only source in the case of a restoration project.

I have no comment about the validity of the filtering/resampling method and how it is represented on Deltawave as well. When in doubt, pkane is the consultant, not me.

In fact, many "killer samples" in lossy codecs are not from audiophile genres as well, a lot of them are electronic music with unexpected waveform, but it does not mean these kinds of music have no artistic value.
 

Blumlein 88

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About the vinyl rip, the CD version of this song is also a bit distorted. Maybe not quite as much as this, but there isn't that big of a difference in the louder portion. I think the original must have been a bit distorted as well.
 

Robin L

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About the vinyl rip, the CD version of this song is also a bit distorted. Maybe not quite as much as this, but there isn't that big of a difference in the louder portion. I think the original must have been a bit distorted as well.
Compressed? Yes, but not clipping like the vinyl rip does. That vinyl rip is not representative of the high quality of the original recording.
 

pkane

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I have no comment about the validity of the filtering/resampling method and how it is represented on Deltawave as well. When in doubt, pkane is the consultant, not me.

DW does no filtering or resampling to align files using the standard settings, so I'm not sure this question even makes sense in this context.
 
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