Volume Automation Clicks and Pops

[Vagelis]

For long time now i 'm very confused about volume automation behavior. I'm trying to automate the volume pre-fx to achieve a gate fx, but i get lots of click and pops with various shapes, especially with square and saw.
For the record i tried with other Daws like Ableton, FL studio and Bitwig and this doesn't happens, it chops the audio smoothly without any artifacts.

I recorded some videos to show this behavior with a saw shape (sorry for the bad quality, please turn on the volume on gifs to listen)

In this video i 'm duplicating the shape to chop the audio without automation items. There are few clicks but not as much as in the next video. (Btw with a square shape the clicks are a lot more!)

https://imgur.com/a/9fvLO9H

In the next video i'm duplicating a part of automation item multiple times and as i can see on the audio file, there's a small transition which helps preventing the clicks. (But again with a square shape the clicks are a lot more noticeable!)

Now the weird part is when i glue those automation parts to one file, the clicks are way more noticeable!

https://imgur.com/a/9LYjOIn

This is really strange behavior that i never saw anywhere else and prevents me to automate the volume and chop the audio files smoothly, which is a huge bummer

Could you please fix this bug or explain what's happening here?

[Reflected]

automation still causes clicks and pops... can't trust it :/

[creal]

In my last project, I encountered crackles each time the tempo envelope started to increase, although it was simple (85 until the middle of the song, then 85 to 90 in 8 bars, then 90 until the end). Please note that I had around 50 tracks, and that I used the auto stretch timebase for quite a few audio items.

The crackle always appeared when the playhead crossed the linear point going from 85 to 90.

It's very frustrating because I lost a lot of time trying to find a workaround. I finally used a bus to output record two bars of the master track in real-time, then did an edit in another project to replace these two bars specifically.

Do you think it has to be reported as a bug?

[Vagelis]

Bump, any chance this could be improved? It's a bummer that I can't use properly volume pre-fx. Thanks!

[Justin]

Can you post a minimal test project that demonstrates the issue?

[creal]

Originally Posted by Justin

Can you post a minimal test project that demonstrates the issue?

Concerning my specific problem (crackles with tempo automation & auto stretch markers), you will find a short (but sufficient) excerpt of my project here:

https://we.tl/t-hl1riF1eRT

Does it help?

[Vagelis]

Originally Posted by Justin

Can you post a minimal test project that demonstrates the issue?

Hi Justin, yes for sure! Unfortunately now I'm away from the city so I can post it tomorrow as soon as I get back home.. but it's easy to hear the clicks when using volume-pre fx with a sustained pad for example, then chop it by automating the volume envelope, using a square or saw shape.
No matter what, I will post a project tomorrow as well.. Thanks!

[Vagelis]

Hi devs I uploaded a simple project example. There are some clicks when chopping the sound with Volume per-fx, using square and saw shapes:
https://drive.google.com/file/d/1luL...usp=drive_link

[mschnell]

When doing hard jumps in parameters (e.g. Volume) artifacts are necessary to appear. That just math/physics, and inherently "correct". For a "musical" result, either slopes need to be used or some kind of smoothing need to be applied under the hood (similar to item crossfades). See recent feature request -> https://forum.cockos.com/showthread.php?t=286351 .

[Vagelis]

Originally Posted by mschnell

When doing hard jumps in parameters (e.g. Volume) artifacts are necessary to appear. That just math/physics, and inherently "correct". For a "musical" result, either slopes need to be used or some kind of smoothing need to be applied under the hood (similar to item crossfades). See recent feature request -> https://forum.cockos.com/showthread.php?t=286351 .

Clicks are not musical, but thankfully it's been fixed in the new dev release..
Btw when using a Daw to record or edit the sound you want a musical output no matter the math. Every Daw that I tested had a smooth Algo for this and now I'm happy we have it in Reaper.

[creal]

Originally Posted by Vagelis

Clicks are not musical, but thankfully it's been fixed in the new dev release..
Btw when using a Daw to record or edit the sound you want a musical output no matter the math. Every Daw that I tested had a smooth Algo for this and now I'm happy we have it in Reaper.

Still have this bug with tempo automation. Can you test on your side, please? (project still available here: https://we.tl/t-hl1riF1eRT ).

[Vagelis]

Originally Posted by creal

Still have this bug with tempo automation. Can you test on your side, please? (project still available here: https://we.tl/t-hl1riF1eRT ).

Yes I can hear the clicks most of the times when the tempo gradually changes to the next marker, but not always which is a bit weird. Like it depends at which position I'm starting the playback.

[creal]

Originally Posted by Vagelis

Yes I can hear the clicks most of the times when the tempo gradually changes to the next marker, but not always which is a bit weird. Like it depends at which position I'm starting the playback.

Thanks for your feedback. Yes, on rare occasions, the glitch does not appear, but most of the time it clearly sounds like a bug to me.

[mschnell]

Like a sudden Volume change, a sudden tempo change creates a sharp edge in a signal. I.e. an artifact audible by high frequency not present in the original signal.

A software might under the hood do smoothing (i.e. modify the user defined change) to trade the artifact's amplitude vs the mathematical correctness of the result.

("Musical" examples:
Volume: a compressor with close to zero attack time is a distortion device.
Tempo: FM Synths create overtones by fast tempo changes of a wave.)

With Items, Reaper shows crossfade curves on the item display to make clear that it automatically did a smoothing of the Item Volume (if configured so). Hence it seems appropriate that Envelope curves show smoothing if a "musical" behavior is desired.

[creal]

Originally Posted by mschnell

Like a sudden Volume change, a sudden tempo change creates a sharp edge in a signal. I.e. an artifact audible by high frequency not present in the original signal.

I agree with you, but in my case (did you try the project I shared?), it's not a "sudden tempo change". It's just a progressive tempo change with a linear ramp. According to Schwa, the problem rather lies in the "auto-stretch at tempo changes" timebase.

[schwa]

Originally Posted by creal

Still have this bug with tempo automation.

This project shows a bug with media item stretch markers that have nonzero slope, which happens when using the auto-stretch timebase combined with "gradual transition" tempo changes. It's completely unrelated to automation. Fixed for the next build, in any case.

[creal]

Originally Posted by schwa

This project shows a bug with media item stretch markers that have nonzero slope, which happens when using the auto-stretch timebase combined with "gradual transition" tempo changes. It's completely unrelated to automation. Fixed for the next build, in any case.

Sorry for the misunderstanding.

I'm glad it's fixed for the next version. Thank you.

EDIT: after testing, it appears that it's not completely fixed yet.

[mschnell]

Great that this is sorted out !

[creal]

Originally Posted by mschnell

Great that this is sorted out !

It's better now but not perfect (see my posts in the last pre-release thread).