Better sample rate conversion (SRC)

If you set your samplerate to 44.1 khz in Renoise and play this 192 khz sample, you can hear some tones that shouldn’t be audible.
The sample contains just a 80 khz tone (inaudible), which on playback gets (aliased?) down into the audible range at around 8 khz.

Taken from this thread at Ableton forums.

Set the “interpolation” algorithm

none of the interpolation options make it silent, at best they only make it a bit quieter

You push the limits

a human can’t even “sense” this frequencies…

But when you understand that a simple sine signal can generate “harmonics”…
I know that is hard to understand…
From a “logic” view,It’s not logic

192khz with HF noise

From the linked sample. Incredibly noisy. Also, this particular sample isn’t the 80khz test tone. It contains multiple test tones midway through the track.


From the 80khz test tone sample from the linked forum thread. This is the one that should have no audible tones. The test tone definitely gets aliased and ends up audible.


You results are non sense


Find a more difficult problem to resolve

Who needs 192 kHz? :thinking: Unless you’re working in a professional high end mastering studio…

And it’s not a problem of Renoise, it’s a problem of the source to destination rate downsampling process while playback. 192 kHz are no multiples of 44.1 kHz, it’s a multiple of 48 kHz. So downsampling 192 to 44.1 can produce disturbing artifacts, which you then will recognize as your mentioned audible “aliazing”. That’s normal, if you try to downsample a rate that is no multiple of the destination rate…
It’s like you try to push a cube through a triangular hole…

To be more precise,i used the word “Aliasing” in the past…(I was drifting?)
“aliasing” is not the problem…
Interpolation is the problem…

Using “multiples”,you erase SRC “muffling” and “noising” problems

Just so easy

But it doesn’t resolve the “realtime” rendering of non multiple rate sample…

“Zplane elastique” has certainly a good solution inside

In the extreme…you can convert vectors to curves…

Have you tried enabling the “AA” button in the sample properties, next to the interpolation method, and set the method to “sinc”?

Yeah renoise’s resampler is not perfect. It seems to use little cpu, but it does classic methods, that alias or only have poor protection.

If what is in the sample is inaudible junk noise anyways, you can also try lowpass filtering the sample.


You trap me👌‍‍


And it’s not a problem of Renoise…

Most audio programs don’t have this problem, though. So you can say it is a problem of Renoise, and of Ableton Live too.

A great video on this.


It is interesting to check it on Even some most expensive DAWs are not perfect for sample rate conversion. A solution is the free software r8brain to do offline sample rate conversion of your samples/rendered tracks.

Yes! Very interesting! After watching this video I checked the saturation effects I usually use with a high pitched sinewave like he does and discovered that some of them add a LOT of aliasing (a reason why my mixes sounded harsh, I didn’t know why until that video) so I don’t use them anymore.

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It’s just like what I was saying when I entering the forum…

It’s impossible to convert non multiple rates without losses

maybe with b-spline…

Yes it is possible (all sample rate conversion using sync interpolation do this) AS LONG AS there is no audio with frequency above half of destination sample rate (e.g nothing above 24kHz if you convert to 48kHz). Otherwise it will result in aliasing noise, unless the resampler has a built-in low-pass filter. As different resamplers use different filters that’s why there is differences between them.

So yes it’s better not to have ultrasonic tone before conversion. I hope this was clear enough :slightly_smiling_face:

What? I literally posted a sonogram of each of the test tones linked by OP. How is that non sense?

I also stated as much in my post. As well as objective fact that the 80khz test tone will alias down into the audible range because Renoise, as best as I can tell, does no filtering when resampling to a new Sample Rate. (Which, for me, is a good thing, i.e. sound design.)

If you want to prevent ultrasonic frequencies from aliasing down when down sampling in Renoise, treat the sample with a Low Pass filter set to your Nyquist frequency before down sampling.

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Guys, please keep in mind, Renoise is a real sampler, while other DAWs are not. I think only if you actually can automate the pitch shifting/time stretching parameters in the DAW, it is calulated in realtime. Not sure if ableton etc do that, I suspect those to do pre-calculation.

A proper comparison regarding aliasing would be Renoise vs Kontakt vs Falcon vs Bitwig Sampler module etc