pops and crackles while using cloud reverb with frequency * 0.5

Question

hello Kyma community

 

Having this issue that can't figure why, always having crackles and pops while using granular reverb (samplecloud) with frequency set to lower than default ( i.e. * 0.5 )

see example attached

example.kym

 

thanks in advance

 

christian

Answer 1

Hi Christian,

If you mean values less than 0.5 in the Freqency fader on the VCS I can see why you are having pops etc.

The frequency fader on your VCS is controlling the low shelving filter (in Frequency hz) not the frequency of the reverb clouds. I'd be using a minimum of 5-20 or so in that field.

Regards,

Sean

Comments

hi Sean,

thanks for taking a look

the frequency I am related is the one on samplecloud itself and not the filter

I am multiplying the frequency to 0.5 so I can have the grains playing an octave below. When I do this it starts to give pops and cracks

thanks in advance for any help

regards

---

I used to feed MemoryRecorder into a bunch of SampleClouds where some were using 0.5 or even 0.25 for the Frequency window. Loved the basic sound, but hated the pops and clicks. Someone here can probably explain why they happen better than me, but I think it has something to do with grains getting truncated. Anyway ....

I've had much better success doing the pitch shift first (using PolyphonicPitchShift Resynth module) then running that into the MemoryRecorder and then into the SoundCloud using "default" in the Frequency window.

I actually included a demo of this technique in my presentation at KISS 2018 (Santa Cruz)

Good Luck!

Answer 2

The basic issue is that, when you are reading out of the memory at a different rate than you are writing into it, and the MemoryWriter is cyclic, there is a possibility for the write pointer to cross the read pointer resulting in a discontinuity.

Here's a Sound that can do clickless granular reverb even when you play back the grain cloud at a different !Rate. For a fun effect, try adjusting !LogFreq (to sweep the pitch of the input sine wave).

Comments

thanks for the example! Now it works like a charm!