v1.24 sounds different from v1.18 - how do i fix?

ida · July 17, 2015, 13:19:57

Hello!

My name is Wouter van Leeuwen. I'm a 16 year old producer from the Netherlands and i make music from 8-bit and Raw Data to Trap and oldschool House. Just gonna leave a link here.

For all of my music i use OpenMPT. Way back in 2008 i was playing some games and one of them used tracker music. I figured i could aswell try tro compose some songs myself - not very good songs, i didn't really share them anywhere. Until a few years ago, when i decided to take music making more seriously and posted some things on my Soundcloud. I like the simple idea of OpenMPT, but i also like how it's combineable with more modern stuff like VST's, although i rarely use those because they'll blow up my old laptop, which is another reason why i fancy OpenMPT.

But recently i ran into a problem. I've been using v1.18.02.00 forever and decided to update, and i got v1.24.04.00. But my songs sound a bit different in the new version. It's especially annoying since i have to open up the old version each time i want to edit some of my songs i made prior to when i updated.

Here you can hear the difference pretty well (unless ofcourse you don't have a Soundcloud account in which case it won't show up). The first sound clip is from 1.24 and the second is from 1.18, how it should be. How do i fix this so that it sounds like 1.18 again?

Thanks in advance!

Saga Musix · July 17, 2015, 14:04:15

There are a variety of reasons why different versions of OpenMPT can sound differently:
- Wrong pattern command interpretation in old versions has been fixed. By using "more IT compatible playback" (default), you will always get the behaviour which is closest to what Impulse Tracker and other programs do, which can vary between OpenMPT versions. Always cross-listen with a good external player like XMPlay to find these differences (and report them if you find one).
- Different playback settings. You will have to find the same settings you used as in the old version.

However, without an example module (and by that I don't mean an MP3 render) I can only make guesses. Private links on soundcloud only work if you provide some kind of access token btw, even if one is logged into the site. But as said it doesn't matter because MP3s are not helpful.

Saga Musix · July 22, 2015, 19:27:22

If you don't provide the example song, there's no way we can help you.

ida · July 22, 2015, 22:26:43

whoops i forgot

I didn't really feel like sending the full song so i forgot about it and then realised i could just copy and paste the bit that sounds different and send that.

But i've put it online now so there you go!

Saga Musix · July 22, 2015, 22:42:11

Congratulations, you have managed to use the resonant filter in a way that would actually reveal the differences between the new and old implementation. For the sake of compatibility with Impulse Tracker filters, the output of the resonant filter was slightly changed in... OpenMPT 1.19 I think, and it most cases the difference is very subtle. Seems like in your case it's not so subtle, and the distortion just makes it even more obvious. I'm afraid there's no easy way to get exactly the old filter behaviour easily in current versions. The main difference is that some bugs in the old filter have been fixed, and that the internal feedback of the filter is limited, which is probably why it sounds a bit more aggressive in 1.18 in your example. A possible solution would be increase the gain on the distortion effect, I think. And possibly amplify the sample waveform by 50% or so, so that this feedback limiter won't kick in. Apart from that, there's not much that can be done.

And yes, thanks for just uploading the relevant part and not entire songs, I am interesting in debugging things quickly and not listening to whole tunes to figure out which exact channel to mute to locate issues.

ida · July 22, 2015, 22:53:58

Eh, it's most the apparent on the track i provided. I can hear the difference in other songs that i've made and it's more subtle, but it still annoys me and after hearing a song a 100 times first and then after that hearing it a few times with the resonance being changed, it doesn't sound like what i have in mind, and i'm very picky when it comes to making everything sound right. I'll try what you said.

Saga Musix · July 22, 2015, 23:03:59

I can understand how tiny differences can make a huge difference to the trained ear, but we cannot carry all old cruft along new program versions. The old filter code could introduce some pretty nasty distortion artefacts that I really wouldn't want to have in the program anymore under any circumstances. To illustrate very nicely why I threw away the old filter code, consider the test cases
"extreme-filter-test-1.it" and "extreme-filter-test-2.it" test cases here: http://wiki.openmpt.org/Development:_Test_Cases/IT#extreme-filter-test-1.it
Listen to them in OpenMPT 1.18 but turn the volume down before doing so.

But of course with OpenMPT you always have the choice to keep going back to an older version and listen to the song in this particular version and listen to newer songs in the current version.