#21

In film music, dialogue, and sound effects work, the go-to plugin for transparent pitch shifting is Pitch-N-Time Pro from Serato. It’s been around for many years. It’s hideously expensive ($800), but it sounds really good. I bought it several years ago and it works very well. You should be able to get +/- 4 semitones without trouble. It has several algorithms to choose from, depending on the material and how far you want to go with it.

There is a first class way that doesn’t require an expensive plugin. It sounds as though you like the tape style pitch shifting in the new IRCAM tool. That Method, varispeed, is the easiest and best method for pitch shifting without artifacts, if it’s acceptable to have the length change at the same time as the pitch. It’s exactly like slowing or speeding up the tape you’ve recorded your sample on: sounds change pitch and duration simultaneously. There are no fft algorithms needed, and it sound great!

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#22

The cleanest way i’ve ever done this (changing the sample rate and replay speed/pitch) was by rewriting the WAV file header with another sample rate, which then makes the software either dynamically resample (usually with interpolation) or resample on import to match the project sample rate, in both cases ending at the speed related to the hacked sample rate. That was the only way I could align recordings from two different recorders, for surround use - had to set one up at 48004Hz. I’ve done this with an arcane piece of software called SoundHack, but anything that messes with the file header (metadata only) should do this for you.

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#23

Ah this is interesting, do you know how to calculate sample rate if I want to transpose by a semitone or two down?

#24

Thanks for your feedback yes varispeed seems to work for this material and with Ircam Lab transposed audio files sounds noticeably better

#25

I think it would be something like:
newSr = oldSr * 2^(p / 12)
with p being the number of semitones.
for example to transpose down a whole step:
48000 * 2^(-2 / 12) = 42763.13847073629
which you would probably want to round to 42763.

This is the formula for transposing a frequency by a certain number of semitones in equal temperament, but it should work for sampling rate as well.

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#26

Thanks so much much! This is actually very elegant and fast way of doing the transposing and it works beautifully with SoundHack. I have around hundred files to transform so it saves some time too…

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#27

The best pitch shifting I’ve ever heard is in the Rossum Assimil8or. Like the pitch shifting is so good you have to kind of rough up the sound later because you have almost no artifacts. It’s a little mind melting.

I used it once to turn a sparrow birdcall into a beautiful woody marimba-like tone. Several octaves, no digital artifacts.

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#28

Found an example of the Assimil8or pitch shift capability. This track (album containing it is PWYC on the Aug 7 2020 Bandcamp Day) is built with a sparrow call I copied from a Youtube video (i.e. really high pitched and not audiophile-quality recording) slowed down with Assimil8or, pinged a vactrol for an envelope, added some noise/grit (everything that isn’t clean sounding is added after the fact via a noisy VCA and the Dave Smith character thingie), some delay and reverb.

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#29

really nice track. Also, cool to hear about the process

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#30

Sounds great, thanks - would love to try that module but I guess I have to limit to software.

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