crackles on volume automation

[musikbear]

sorry, but i read herris' issue as if all automation resulted in crackles, and as you can hear, his file sounds very different on my lmms. The only dials that will course severe artefact for me, is the LFO SPD on presets.
Take a look at this:
https://www.youtube.com/watch?v=fCRsPzJ_nrs

[heris456]

No crackles on one mashine and crackles on two. I think, this is a software bug.

[AncientMind]

To be honest, musicbear: You know, that there was a good explanation of diiz for crackles... Of course we said (at that time), that an automation with slower reaction (slower attack and decay) the energy of crackles will be reduced. But if you remember: When I first wrote about this noise, I used a bass frequency and - of course - a sine wave. Everybody who knows how a 'sound' can be analyzed to sine waves of different frequencies and phases (better known as Fourier analysis) is aware of the fact, that a crackling will hardly be audible, if the whole sound consist of frequencies which overlay the crackles (since the spectrum of crackles are nothing else than high frequent sounds). That's why I used a bass sine wave to show this noise instead of a saw wave, which hides it instead.

But another time... to be honest: As long as even such simple knowledge is not known throughout the community (while the majority of users not even seem to recognize such noise at all... ) it's no wonder, that such an unwise sound-/signal handling like described by diiz (

The crackle (in this case) is caused by too fast amplitude modulation. With our current handling of volume (no sample-exactness), all knobs (models) get modulated on a per-period rate: meaning that the value of the model gets changed every n frames, where n = period size (somewhat incorrectly called "buffer size" in preferences). This means that there will be sharp spikes in volume, and those cause crackling/popping artifacts.

With the sample-exact models feature, models will be able to receive sample-exact data from controllers, automations etc. This means that volume changes every frame, instead of every n frames, so volume changes are smooth and crackle-free. This is already a working feature in 1.2 (current master), in which you'll be able to eg. connect a controller to a mixer fader and have it modulate the amplitude smoothly.

) was able to stand years (!!!) of LMMS' life.

There is a lot of work to do for LMMS' developers - I know. This point only is one of many others - but it is one.