Plugin Oversampling Occasionally Breaks

Sillypsybin · 05-24-2022, 07:58 AM

I'm loving the oversampling option for plugins. On some (not all) plugins, the difference is pretty stunning. Super smooth and clean.

But once in a while I've been running into some strange behavior. I'll get a mix going, and selectively engage oversampling (I don't oversample fx chains, just individual plugins), and it sounds fabulous, and works fine for days.

However, once in a while, the oversampling seems to break on some plugins. Not all of them, nor every instance of a certain plugin. Doesn't seem to be associated with any particular brand of plugin either. Some tracks using the same plugin will be fine. But on the ones that break, the sound becomes horrible, thin and brittle.

Once the oversampling is broken, it won't matter if I go way back in undo history to a point before I engaged the oversampling. The plugin will work fine without the oversampling, but when I return to the any point after I had engaged the oversampling, the plugin remains broken (odd clue there?). Closing Reaper and restarting does not fix this. Nor does restarting Windows.

However if I individually 'reset' the oversampling, plugin by plugin, track by track, by returning them to 'no oversampling', and then immediately re-engaging the desired oversampling rate (I think the mix has to be running for this to work), the oversampling works great again and it sounds fantastic.

And then I can continue to work on the mix again for days at a time with no trouble.

It's odd.

I'm not sure if it's actually a bug or not. My experience with Reaper has taught me that if I think I've found a bug I probably have not. Usually I'm just doing something stoopid. The bug is me, lol! So I apologize if I'm posting this in the wrong place. But this is strange and I can't really figure it out.

The good news at least is, if my mix goes bad on me all of a sudden, at least there's a way for me to get it back, by restarting the oversampling, plugin by plugin, track by track. Which is kind of a pain, but it works.

I suppose I could just not use the oversampling at all, but that's a drag because it sounds so good on certain plugins when it's not broken.

Anyway I thought I would just toss this out here for the heck of it.

Thanks everybody!

P.S. I'm using a Lenovo Think Station with an Intel i9-10900K processor & 32GB RAM, Windows 10 Pro (21H1), fully up to date.

Sillypsybin · 05-24-2022, 05:42 PM

There also seems to be some interaction with other open tabs. For instance, when I ran into this problem again today (a couple tracks with a few oversampled plugins that had been sounding great suddenly started sounding brittle and thin), closing a tab that also had the same oversampled plugins seemed to fix the problem.

Sillypsybin · 05-25-2022, 05:59 AM

1. I rendered a mix yesterday that sounded great.

2. The original mix project was open in Reaper (tab 1).

2. In a new tab (tab 2), I opened the project file created automatically yesterday when I rendered the mix. Undo history is at Initial State. The mix now sounds different. The floor tom and the guitar both sound brittle.

3. With undo history still in initial state I rendered that project file in tab 2 and did a null test comparing the new render with the original render.

4. Sure enough, in the null test I hear the guitar and the floor tom. They sound the opposite of brittle and thin, that is to say they sounded dull with the top end muted.

5. I restarted the oversampled plugins on the floor tom and the guitar tracks in the automatically created project from yesterday in tab 2, but to my surprise there was no change.

6. Then I closed the original project in tab 1, and immediately went back to the automatically created project which had been in tab 2. Upon listening, the guitar and floor tom no longer sound brittle. Closing the original mix in tab 1 seemed to fix that.

7. Then I rendered the project file making sure I was at initial state in undo history, and I did another null test. I no longer heard the floor tom and the guitar, but instead heard a different guitar and the snare drum, both dull, with the top end muted (!). It's sort of like playing whack-a-mole.

8. I then went into each track one by one, and comprehensively restarted every single oversampled plugin in the project. Once that was done I returned undo history to initial state and rendered the project. It sounded good. I did a null test and it checked out. Compared to the original mix, the newest render completely cancels all sound when it is switched out of phase.

RJHollins · 05-25-2022, 06:47 AM

What plugin[s] ?

Project Samplerate ?

Oversampling Rate ?

Sillypsybin · 05-25-2022, 07:03 AM

Project Sample Rate: 192kHz

Waves plugins: Abbey Road Saturator, CLA-2A, API 2500, API-550B, dbx-160, PuigChild 660, Aphex Vintage Exciter

Fab Filter plugins: Pro-Q-3, Pro-DS, Pro-L2

Oversampling rate: 705.6k/768k

Intel i9-10900K processor & 32GB RAM, Windows 10 Pro (21H1), fully up to date

No performance issues other than oversampling weirdness

Justin · 05-25-2022, 07:06 AM

Is the project samplerate the same in both project tabs? Have you verified the audio device samplerate doesn't change between various points on your test?

(also, might be worth checking that the project samplerate conversion mode is the same for both render/playback, and that it is the same in the two copies of the project)

At any rate, it's entirely possible that various plug-ins that you're using do not behave predictably at 768khz, as most people will never use this frequency. If you can come up with a similar test that uses all REAPER built-in plug-ins, do post it here!

Sillypsybin · 05-25-2022, 07:26 AM

Hi Justin, thanks for checking in. Sample rate is the same in both projects. The second project is the one that was automatically created when I rendered the first one, so it's identical. Sample rate is the same for both render and playback (as set in Project Settings and Render). I haven't seen any changes in my device sample rate either. (SSL 2+)

I hear you about the third party plugins and 768k. I'll do some further testing with Reaper plugins, and I'll get back if there is any more weirdness.

RJHollins · 05-25-2022, 01:01 PM

Quote:

Originally Posted by Sillypsybin

Project Sample Rate: 192kHz

Waves plugins: Abbey Road Saturator, CLA-2A, API 2500, API-550B, dbx-160, PuigChild 660, Aphex Vintage Exciter

Fab Filter plugins: Pro-Q-3, Pro-DS, Pro-L2

Oversampling rate: 705.6k/768k

Intel i9-10900K processor & 32GB RAM, Windows 10 Pro (21H1), fully up to date

No performance issues other than oversampling weirdness

You're running the session at 192kHz .... and you are then Oversampling ?

at 192 ... no OS needed.

2nd ... I see a few WAES plugs ... go to WAVES site and lookup the highest samplerate that each plugin can run. You are way over the top with that.

Sillypsybin · 05-26-2022, 07:14 AM

I'm going to respectfully disagree with you on this. Reaper offers oversampling at 768k - 4 times 192k. It's being offered for a reason.

And bottom line, my ears hear a significant difference on these plugins, depending on the source material (doesn't make much difference on a bass track for instance). And it's borne out by doing null tests.

If you want to know why oversampling at 768k makes a difference, and what plugins this will work with, watch this video by Dan Worral: https://www.youtube.com/watch?v=GjtEIYXrqa8

Might be better to carry on the debate about this in General Discussions.

Quote:

Originally Posted by RJHollins

You're running the session at 192kHz .... and you are then Oversampling ?

at 192 ... no OS needed.

2nd ... I see a few WAES plugs ... go to WAVES site and lookup the highest samplerate that each plugin can run. You are way over the top with that.