How High of a Sample Rate is Enough?

[andreasmaaan]

Heh, so it's false experiment, but the question still remains if the difference between sine wave and a square wave could be heard if the levels are matched. But, as I said previously, this experiment should be taken wither with analog signals or the ones with natively higher res than 44.1kHz.

I'm not sure I understood that part of your point actually. Why should analogue signals be used?

 

[Krunok]

I'm not sure I understood that part of your point actually. Why should analogue signals be used?

If you want to test if 44.1kHz sampling cuts the harmonics that can be heard than you should use either analog signals or signals sampled with higher frequency, right?

 

[andreasmaaan]

If you want to test if 44.1kHz sampling cuts the harmonics that can be heard than you should use either analog signals or signals sampled with higher frequency, right?

Ah yeh, agreed. Thought you meant it should be an analogue signal, period. But hi-res digital would also be fine.

 

[andreasmaaan]

Although, I don't see how if humans cannot hear fundamentals at 22KHz, they can miraculously hear harmonics at the same frequency.

 

[Krunok]

Although, I don't see how if humans cannot hear fundamentals at 22KHz, they can miraculously hear harmonics at the same frequency.

I agree, I don't really think we can. But in that case all that talk about HiRes is snake oil.

 

[Kees de Visser]

IME most digital signal generators suffer from aliasing, which can (will) be audible with square waves.
This website offers pretty clean test signals (the basic ones are free) for download. Highly recommended.
https://www.wavtones.com/functiongenerator.php

Our tone generators have been designed to minimize those unwanted frequencies. When we generate a square tone, we synthesize a waveform that has been designed to sound as close as possible to the square tone, not the square waveform itself. Our samples are no longer aligned and the transition is smoothed so additional frequencies are not introduced. The result of this process is illustrated in the figure shown on the left side of this paragraph. Our waveforms may look worse, but they actually sound better!

 

[Fitzcaraldo215]

I agree, I don't really think we can. But in that case all that talk about HiRes is snake oil.

I agree about the human frequency response limit to 20k, or usually less for adults, if and only if there are no audible effects, including also time domain effects, from filtering. But, also, it is dramatically oversimplifying our hearing mechanism to just look at harmonic distortion and its ultrasonic frequency products alone, and that may lead to false conclusions.

So, it is perhaps still possible that hirez may have audible advantages in spite of the frequency response limit. Among others, I would consider the shifting to higher ultrasonic frequencies further away from the audible band of filter artifacts in hirez A-D and D-A.

 

[andreasmaaan]

IME most digital signal generators suffer from aliasing, which can (will) be audible with square waves.
This website offers pretty clean test signals (the basic ones are free) for download. Highly recommended.
https://www.wavtones.com/functiongenerator.php

The spectrum graphs I posted screenshots of seem to show that aliasing is not an issue with the tone generator that @SIY posted either.

 

[andreasmaaan]

I agree about the human frequency response limit to 20k, or usually less for adults, if and only if there are no audible effects, including also time domain effects, from filtering. But, also, it is dramatically oversimplifying our hearing mechanism to just look at harmonic distortion and its ultrasonic frequency products alone, and that may lead to false conclusions.

So, it is perhaps still possible that hirez may have audible advantages in spite of the frequency response limit. Among others, I would consider the shifting to higher ultrasonic frequencies further away from the audible band of filter artifacts in hirez A-D and D-A.

But isn't ultrasonic simply ultrasonic (for any given person ofc)?

 

[Kees de Visser]

The spectrum graphs I posted screenshots of seem to show that aliasing is not an issue with the tone generator that @SIY posted either.

Interesting. I clicked on the "Save" button and analysed the saved files (= aliasing). Did you do the same ?

 

[andreasmaaan]

Interesting. I clicked on the "Save" button and analysed the saved files (= aliasing). Did you do the same ?

No, I played them from the website and recorded them using my DAW. Did you see aliasing when "saved" directly from the website?

 

[Krunok]

So, it is perhaps still possible that hirez may have audible advantages in spite of the frequency response limit. Among others, I would consider the shifting to higher ultrasonic frequencies further away from the audible band of filter artifacts in hirez A-D and D-A.

I think if the audio science still cannot make a scientific judgment if HiRes may or may not have audible advantages over RBCD than it is questionabe if true audio scientists exist at all.

 

[Kees de Visser]

No, I played them from the website and recorded them using my DAW. Did you see aliasing when "saved" directly from the website?

Yes I did see aliasing, nicely spaced at 100Hz intervals. Not very loud, but not ok for a critical listening test IMO.

 

[andreasmaaan]

Yes I did see aliasing, nicely spaced at 100Hz intervals. Not very loud, but not ok for a critical listening test IMO.

I guess you can see from my screenshots that the aliasing wasn't present in my case. Still, there does seem to be a bit of noise in there. Shouldn't trust any online source enough for listening tests without properly measuring beforehand I guess.

 

[Blumlein 88]

Okay look, here is a better way to test what you want to test. Make sure your playback system can work at 96 khz or 192 khz. Make a 12 or 11 khz or whatever tone you want. Then make and add to it twice that and thrice that. Compare the pure sine with the sine plus 2nd and 3rd harmonics. Both harmonics being ultrasonic. See if they sound different.

I can make the signals for you if you wish. Tell me what tone you want to use as the base.

 

[Krunok]

Okay look, here is a better way to test what you want to test. Make sure your playback system can work at 96 khz or 192 khz. Make a 12 or 11 khz or whatever tone you want. Then make and add to it twice that and thrice that. Compare the pure sine with the sine plus 2nd and 3rd harmonics. Both harmonics being ultrasonic. See if they sound different.

I can make the signals for you if you wish. Tell me what tone you want to use as the base.

I would appreciate if you make a the test signals as I don't have the software to do it.

Please make 4 test signals with 192kHz bitrate, flac or wav format would be perfect:

11kHz
11kHz + 22kHz (50% lower amplitude) + 33kHz (25% lower amplitude)
7kHz
7kHz + 14kHz (50% lower amplitude) + 21kHz (25% lower amplitude)

Thank you!

 

[Blumlein 88]

I would appreciate if you make a the test signals as I don't have the software to do it.

Please make 4 test signals with 192kHz bitrate, flac or wav format would be perfect:

11kHz
11kHz + 22kHz (50% lower amplitude) + 33kHz (25% lower amplitude)
7kHz
7kHz + 14kHz (50% lower amplitude) + 21kHz (25% lower amplitude)

Thank you!

Okay, you want a separate file for each? And how long to you want it? 30 seconds for each signal good?

 

[Krunok]

Okay, you want a separate file for each? And how long to you want it? 30 seconds for each signal good?

Yes, separate files, 30 seconds is perfect. Thank you!

 

[Blumlein 88]

Okay one zip file. Opens into FLAC format. 30 seconds per file. The fundamental is -6 db for each. Potentially tweeter busting levels. Be easy on the volume till you choose an appropriate level.

 

[Blumlein 88]

Bonus file. 7 khz and 14 khz without 21 khz.