Sample Rate Converting to Norns

SamRay · 2021-07-22T01:05:39.801Z

I’m in the process of preparing audio for my Norns and noticed that the supported sample rate is 48khz. I’ve been working in music for nearly a decade now and nearly all of my audio/samples/field recordings are in 44.1khz. Will I need to manually convert any audio files I want to import to Norns to 48khz (or resample within the Norns before using any imported audio)? Has anyone found a more streamlined way to batch convert audio for importing? Apologies if this question has already been answered somewhere else, I was unable to find it.

widdly · 2021-07-22T01:17:07.447Z

I use sox SoX - Sound eXchange | Documentation. It can do all sorts of things including batch format conversions.

SamRay · 2021-07-22T01:29:36.229Z

Thank you for the recommendation!

coreyr · 2021-07-22T02:48:50.043Z

For the most part, norns does not care. There are a few scripts that are very picky and your samples MUST be 48k to work. Buoys for example will let you know that your samples are at the wrong sample rate.

Things like tape (the internal recording and playback feature that runs parallel to your active script) seems to be sample rate agnostic for playback.

kasselvania · 2021-07-22T02:57:25.015Z

From what I’ve seen, mlr actually has some odd speed discrepancies when loading samples of different rates. I had 48khz samples become out of sync with 44khz samples.

zebra · 2021-07-22T09:56:57.887Z

in general, soundfiles will be loaded without complaint regardless of samplerate, but not resampled. so they will play back at the wrong speed if they are not 48khz.

this definitely applies to softcut and TAPE. it is also the off-the-shelf behavior for reading soundfiles into buffers in supercollider, so all the existing sample-based engines i’m aware of also behave this way.

of course we could add resampling-on-import functionality to crone and/or supercollider. but to cut to the case, it is sort of a pain and there are probably more edge cases and little details than we want to worry about. on balance i think it’s better to prepare samples as 48k on disk.

swhic · 2021-07-22T09:59:19.821Z

on a side note it does not play 32 bit files. any adjustments possible?

zebra · 2021-07-22T09:59:54.511Z

what doesn’t? i use 32b float wavs pretty regularly… all formats supported by libsndfile should work. but it would not be the first time i encountered a libsndfile bug for some particular format/container combo. (like 32b FLAC or something.)

swhic · 2021-07-22T10:24:58.947Z

my bad…it is a 4 channels 32 bit wav!

xmacex · 2021-07-22T11:24:39.445Z

Absolute classic tool! I remember using it for something in the 1990s, and still going strong. I <3 command line.

SamRay · 2021-07-22T23:42:56.013Z

That makes total sense. Thank you for your response and explanation!

_pete · 2024-02-05T23:59:12.044Z

Hey all,

I’m experiencing (as the title would suggest) odd, inconsistent behavior from the TAPE engine - particularly, inconsistency with which the TAPE plays back imported audio recordings pitched up by about a whole step. Let me explain.

When recording to and playing back audio recorded natively within Norns from the tape folder in Norns (I’m experiencing this issue on a silver stock Norns running 231114), audio plays back without any change, as expected. However, when I make a new folder (in my case, my name, /pete) in the norns directory, outside of the /tape folder, and attempt to play back imported .wav files, they play back pitched up. I simply can’t make head or tail of it.

I’ve tried A/B testing the files by previewing them in Finder on my Mac, sitting in either the separate folder or the /tape folder. The files aren’t being pitched up or changed when I import them to the Norns (when I play them back in Finder), but no matter where I place a non-native-to-norns audio file, it will play back pitched up by just around a whole step (annoyingly, just under a whole step), by some odd phenomenon, when I attempt to do so from the TAPE menu.

This is an issue I’d love any and all insight on - I’ve attempted everything short of a fresh install. Any help would be appreciated, as I was hoping to use Norns’ tape functionality to play prepared material live while I improvise.

xmacex · 2024-02-06T00:05:08.773Z

What kinds of sample rates do your files have? Norns generally likes 48000.

_pete · 2024-02-06T01:35:24.405Z

I’ll check! Wasn’t aware that this was related to sample rate.

Edit: one of the files I was experiencing issues with was at 44.1kHz. Re-exported at 48kHz and the issue was fixed. Thank you so much for your help, @xmacex !

21echoes · 2024-02-06T04:49:49.245Z

to keep rabbit-holing and get an exact answer, you convert bases for exponential/logarithmic relations by dividing by ln (or log):

you have the ratio 48000/44100, and you want to express it as a power of 2^(1/12) (one semitone):
ln(48000/44100) / ln(2^(1/12)) => 1.467 semitones