Importing MOD files - why get the notes transposed down?

Help, Support & Bugs Beginners Questions - Renoise
1

I do understand that Renoise doesn’t claim to import/play MOD files 100% correctly - but I tried anyway :wink: and I wonder:

Why do the notes get transposed down by 2 octaves and 5 semitones?
Is there any explanation for that?
My first assumption was that the reason are the different sample rates of Renoise (44.100 Hz) vs. MOD (8.000 Hz?) but 2 octaves and 5 ST should be a factor around 5.34 (I think) and this doesn’t match.

Funny thing is: All the MODs I tried get played more or less correctly (besides minor adjustments like correcting the volume in the sample properties - which is -INF db sometimes).

2

8000 x 2 ^ (2 + 5/12) is the closest to 44100 you’ll have. 2 + 6/12 is too high, and 2 + 4/12 is lower.
The exact transposition would be 2 octaves and 5.5524 semitones

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3

Ok, so my assumption (Reason is shifting the notes down to compensate for the higher sample rate) was correct?

The more I think about it the more I understand (hopefully) what happens when a MOD file is imported:

  • The included samples are treated as raw data.
  • Because Renoise defaults to a sample rate of 44100/s it calculates a “correction factor” (eg. 5.513 when the imported sample rate is 8000/s).
  • After that the pitch of the notes is transposed accordingly so that the resulting sound is correct (-2.463 octaves in my example which is -2 octaves / -5.55 ST).

So the next question: Is it possible to revert this (so that the notes are at the original pitch again)? Adjusting the sample doesn’t do the job.

4

Any ideas anyone?

5

sure, you could try opening the advanced editor and transpose the whole song up by 29 semitones, like so

Screen Shot 2023-09-21 at 1.18.59 PM
Screen Shot 2023-09-21 at 1.18.59 PM324×954 72.7 KB

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6

The are type 1 and type 2 MODs, as far as I remember. There is a way to use some other tracker to convert mod1 to xm first, and THEN import it into Renoise, and everything will be alright. Was it Screamtracker, I can’t remember…

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7

Oh, of course. :roll_eyes: Thanks!
Why didn’t come this to my mind…

But what about the samples?
How can I edit/transform the sample to be at the original pitch?

8

Thanks for the hint. Went searching a bit about different types of MODs … didn’t find anything so far.

BUT … your answer brought me to the following idea:
What if I save the MOD as XM (using MilkyTracker’s Disp Op. > Song: Save As XM)?

Tried that, opened the resulting XM in Renoise and … BIG surprise:

  • The notes are the same as in the original MOD (no downshifting be 2 octaves + 5 ST)
  • The samples are the same pitch as in the original MOD. To be precise, there is a very small variation (C4 plays as 525.1 Hz in Renoise instead of 522.6 Hz in MT or +0.5% which equals to less than 0.1 ST)
  • So the song in Renoise looks (and sounds “almost”) the same as the original!

Strange observation though:
Renoise says the samples are [44100Hz 32Bit Mono] and they contain the same number of samples as in the original MOD file.
When opening the original MOD file in Renoise it says the samples are [44100 Hz 8Bit Mono].

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