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Topic: Testing audiophiles and other things.. (Read 3899 times) previous topic - next topic
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Testing audiophiles and other things..

I came across an interesting tool when experimenting with resampling
HD audio.  The foobar DSP 'resampler dbpoweramp'.

Out of curiousity , I applied several settings to when listening to music.
On nightwish 'everdream EP' which has nice crisp HF;

I rate it with out abx

-22500 , HF coloration obvious
-24000,  much better but still there
-32000, Cant say 100 %, but suspect its still there.

So, You can use this for people who won't take an ABX but don't tell them exactly
what your doing. Ask them which track has the most HF details etc..
Then you will know more or less accoding to how they answer the test.

Re: Testing audiophiles and other things..

Reply #1
Ah, my favourite genre, testing hi-res fans on 32 khz tracks.
Opus VBR 256 + SoX

Re: Testing audiophiles and other things..

Reply #2
I came across an interesting tool when experimenting with resampling
HD audio.  The foobar DSP 'resampler dbpoweramp'.

Out of curiousity , I applied several settings to when listening to music.
On nightwish 'everdream EP' which has nice crisp HF;

I rate it with out abx

-22500 , HF coloration obvious
-24000,  much better but still there
-32000, Cant say 100 %, but suspect its still there.

So, You can use this for people who won't take an ABX but don't tell them exactly
what your doing. Ask them which track has the most HF details etc..
Then you will know more or less accoding to how they answer the test.


If you're anything above, what, 30 years of age, that 32000hz is actually the highest sample rate for you anyways... cuz high frequency loss around 30s adds up to around 15-16khz

which is why, you're not able to recognise things at 32000hz... that's not snake oil being exposed but simple physics

the dbpoweramp ssrc is still one of the very strong filters, that creates heavy pre and post ringing due to the ridiculously steep filter shibata used... try something gentler like SoX resampler in High Quality mode with "aliasing enabled" which is just their jargon for using a gentler filter, which does more justice to the impulse response hence the transients.


Re: Testing audiophiles and other things..

Reply #3
SOX seems to miss the frequency it was asked to filter, by a good 2 - 3 KHZ


Re: Testing audiophiles and other things..

Reply #4
I just use foo_dsp_resampler (SoX) and default settings with foobar2000's auto resampling. For RG scan I also use default settings with 4x upsampling and the results would be quite compatible with many other true peak scanners.

Also, I set the quality to normal instead of best, and only use best quality when doing experiments and dealing with test signals.

RetroArch's highest setting is somewhat similar to SoX's normal quality with default settings (95%, linear phase, no alias), but slower. Also, from my observation, in foobar2000 x64 both SSRC and foo_dsp_resampler render to 64-bit float while RetroArch uses 32-bit float, though this behavior may change in future updates.

I have some game rips with 24kHz and 37.8kHz sample rate and the 24kHz ones would sound quite bad when the filter is too accurate.
https://hydrogenaud.io/index.php/topic,120491.0.html


Re: Testing audiophiles and other things..

Reply #6
SOX seems to miss the frequency it was asked to filter, by a good 2 - 3 KHZ
SoX has  a default bandwith of 95% like the picture of danadam nicely shows. No idea how this SRC comparison pic was done.
Is troll-adiposity coming from feederism?
With 24bit music you can listen to silence much louder!

Re: Testing audiophiles and other things..

Reply #7
SOX seems to miss the frequency it was asked to filter, by a good 2 - 3 KHZ



maybe look at the impulse response of this wav... that good 2-3 db roll off for the last 2-3 khz is required for it to not mangle the transients, compared to the excessively strong ringing of the ssrc filter, cuz of it's extreme steepness to look like "an ideal low pass filter" completely dismissing the fact that this ideal filter does not generate an ideal impulse response...

Re: Testing audiophiles and other things..

Reply #8
here are the proper comparisons with a proper y axis, the previous plots were showing differences at +-2dB of level -.-



the gentler roll off at the frequencies above the hearing threshold of 20khz, leads SoX to generate a far, far superior impulse response, leading to a natural sound, that isn't audiophile mumbo jumbo, but basic physics of audio...

here's the impulse response of this "proper" ideal filter compared to SoX:


The Ideal filter does not, and cannot, generate a proper impulse response, unless someone can somehow reverse the laws of physics and prove the nyquist shannon theorem wrong. The only way to achieve that would be a ridiculously aliasing one that would make audio mirror back way inside the audible frequencies, as is the case with those free to use audio converters etc ... using a "Linear" src that give you an 1:1 impulse response but alias like s...

here's one:

SecretRabitCode Linear Mode:



what a beautiful impulse response

let's see, further



whoops



;-;

this ofcourse doesn't use a filter, to achieve that 1:1 response, because using a filter here, that's exactly at the corner of nyqust limit around 22050hz would take us back to square one, the dbpoweramp converter

which eliminates the aliasing of this colorful (pun intended) src but in turn sacrifices the impulse response to achieve that

hence, mastering engineers use a filter which is the balance of these two, i.e., use a gentler role off at an earlier frequency so that you don't get audible aliasing whilst preserve a good enough impulse response, which leads us back to converters like SoX high quality with aliasing enabled... and ofcourse the Weiss Saracon, a multi thousand dollar SRC used by Hollywood mastering studios, which is what the SoX response seems to be replicating for me... for free.

 

Re: Testing audiophiles and other things..

Reply #9
the gentler roll off at the frequencies above the hearing threshold of 20khz, leads SoX to generate a far, far superior impulse response, leading to a natural sound, that isn't audiophile mumbo jumbo, but basic physics of audio...
The fear of ringing only was created to sell solutions against it to a gullible audiophile crowd. For 44.1kHz audio this is a non issue until i oversaw some recent listening tests. This is one of the best ideas in the history of audio marketing.

Edit: If the filter is that steep as with dBPowerAmp its ringing is massive at 22.05kHz. Almost any DAC has a far less steep filter for playback so filters this out anyway. This stuff is really very theoretical.
An advantage of less steep filters is that it also introduces less clipping.
Is troll-adiposity coming from feederism?
With 24bit music you can listen to silence much louder!