Ableton SRC weirdness/bug
Ableton SRC weirdness/bug
I noticed that if a 192kHz recording has noise in the very high inaudible range (above 50kHz), Live's resampling dumps this noise into the audible range, when playing back or rendering at 44.1/48kHz. Whether High Quality sample rate conversion is enabled or not makes no difference.
Example file: https://filepost.io/d/eVm88um7jY
I thought Ableton used SoX for resampling, but SoX doesn't have this problem and neither do other apps/DAWs that I tried.
Example file: https://filepost.io/d/eVm88um7jY
I thought Ableton used SoX for resampling, but SoX doesn't have this problem and neither do other apps/DAWs that I tried.
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Re: Ableton SRC weirdness/bug
Just out of curiosity what interface were you using to record 192kHz at?
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Re: Ableton SRC weirdness/bug
tried your file playing at 44.1 and 48 and i hear the same - the high freq dithering noise gets pushed into audible range.
out of curiosity i made a 192 khz test tone file in izotope rx (constant sine tone at 80 khz)
playing this file back in Live at 44.1 khz plays the tone at a very audible 8 khz
file is here if interested: https://filepost.io/d/B7xUormuHz
out of curiosity i made a 192 khz test tone file in izotope rx (constant sine tone at 80 khz)
playing this file back in Live at 44.1 khz plays the tone at a very audible 8 khz
file is here if interested: https://filepost.io/d/B7xUormuHz
Re: Ableton SRC weirdness/bug
That was with an onboard Realtek line input, but I've seen some similar stuff with other gear.
High frequency noise is not that uncommon, whether it's from dithering or something else. Here's Amir from ASR rambling about it, for instance: https://www.youtube.com/watch?v=THjusVQpPMA
Yep. At 192 kHz you can also get some audible tones with your file in Live if you change the pitch (like +21 semitones) or if you load it in Simpler and play with it.garyboozy wrote: ↑Fri Jul 30, 2021 4:38 pmtried your file playing at 44.1 and 48 and i hear the same - the high freq dithering noise gets pushed into audible range.
out of curiosity i made a 192 khz test tone file in izotope rx (constant sine tone at 80 khz)
playing this file back in Live at 44.1 khz plays the tone at a very audible 8 khz
file is here if interested: https://filepost.io/d/B7xUormuHz
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Re: Ableton SRC weirdness/bug
Don’t record at 192k? Especially using the onboard audio interface.
Re: Ableton SRC weirdness/bug
Heh, I don't think that's a good solution.
Some users are going to deal with 192 kHz and ultrasonic content nowadays, it is what it is. And if those users are not aware of these SRC issues, they might assume their audio clips are permanently damaged. Live should handle this better.
I tried these files in other apps (Reaper, Acoustica, Audacity, some media players...) and none of them produce audible tones. Well, Reaper does if you select a low quality SRC mode, but not by default.
Some users are going to deal with 192 kHz and ultrasonic content nowadays, it is what it is. And if those users are not aware of these SRC issues, they might assume their audio clips are permanently damaged. Live should handle this better.
I tried these files in other apps (Reaper, Acoustica, Audacity, some media players...) and none of them produce audible tones. Well, Reaper does if you select a low quality SRC mode, but not by default.
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Re: Ableton SRC weirdness/bug
fwiw, Bitwig also plays back that 80khz tone as 8khz (with audio output set to 44.1)
Re: Ableton SRC weirdness/bug
Just to clear this up, because I think I know what's happening now. I was also confused by Live's excellent result on this SRC comparison website, since I was unable to reproduce that result by loading the 96k test file (sweep) in a 44k project.
Live does use a high quality (SoX) SRC, but only for downsampling the rendered audio, if it's needed when exporting. Otherwise, for playback and rendering, it uses a lower quality mode.
Also, from the manual:
If you export at a sample rate that is lower than your current project sample rate, Live will first export at the current project sample rate and then downsample the file in a second step using a high-quality process.
So, as long as you work at 44.1/48k in Live, those 192k samples will produce extra tones/noise, both during playback and in the rendered/exported files.
But if you work at 192k (aka if your audio device is set to 192k in Live) you can then play back those samples and export them to 44.1k without any issues, since in that case Live renders at 192k and then downsamples with a higher quality SRC. Well, at least if you're not doing any pitch changes and such—that uses its own SRC/interpolation, which can be noisy even at 192k.