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Delay issue in Kyma 7 patch, not present in Kyma X

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Greetings all - I'm still new to Kyma 7 with some experience with Kyma X, so please excuse me if I use the incorrect terminology or am missing something obvious.

My current project involves carrying out real-time processing on live acoustic drums, where the audience can simultaneously hear the acoustic sound directly, as well as the processed sound via the speakers. As a result, it's very important for me to keep the signal chain as low latency as possible to avoid unwanted phasing and galloping between the acoustic and processed sounds.

At the most basic level, say I have a kick drum go through an EQ and Compressor (in Kyma) with a wet/dry mix knob afterwards. In Kyma X with my Capybara 320, there is no observable latency between the dry sound and the EQ/Compressed sound, and the mix knob works as expected. When I loaded this patch in Kyma 7++ with a Paca (with MOTU 896 mk3 firewire interface attached), the EQ/Compressed sound is noticably delayed compared with the dry sound, and there is galloping between the two with the mix knob in the middle.

Since this delay is occuring within the Kyma patch itself, it seems unlikely to be directly related to audio interface latency / buffer sizes etc.  Has anyone experienced such an issue before? Could there be an issue with the translation of the patch from X to 7? Does the Paca work differently to the Capybara in this respect?

Any help or ideas would be greatly appreciated!

Thanks a lot
asked Dec 12, 2021 in Using Kyma by jason-long (200 points)
Hi Jason, is it possible that there is a delay in the patch that has live EventValues in it that are set by a preset? Could you please send the patch so we could give it a try?
Hello - thanks a lot for your reply. I don't think there is a deliberate delay added anywhere in the patch, or saved presets.

I wasn't sure how to attach the file to this comment, so here is a download link: https://we.tl/t-ifv5AMLYnb (only valid for a week). The .kym file has a few variations of the patch included, but to attempt to recreate the issue I described, I would load up the 'ButtyBeat' sound, send a repeating percussive sound through Ch1 (kick), and manipulate the Compressor->Mix knob on the VCS. On my Capy there is a seamless mix between the incoming sound and the EQ/Compressed sound, while on the Paca there is a short galloping delay between the two.

There is also a MIDI triggered envelope (for the kick, MIDI Note 60 or 61, Ch1) included later in the chain for bleed elimination, so it's necessary to either remove that, or send those MIDI notes in with the kicks.

It would be great if anyone could test this out (on their Paca(rana) and/or Capy) and let me know if you're able to reproduce this, or if you have any ideas about what might be causing it. Thank you!

2 Answers

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Best answer

Thanks, Jason!

First, the workaround: Change the Delay parameter in Compressor dB from 0 to 1 samp.

Now the explanation: the compressor requires a minimum of one sample delay so it can compare the current to previous outputs. In the Capybara code, we always added 1 to the delay time, so it allowed for 0 s in the Delay parameter field. On the Pacarana, a 0 delay wrapped around to become the maximum delay of 4096 samples.

This has now been fixed and will show up in the next Kyma 7 update (but as a workaround, you can explicitly set the delay to 1 samp).

Thanks for reporting this!

answered Dec 15, 2021 by ssc (Savant) (128,160 points)
selected Dec 19, 2021 by jason-long
It's working correctly now in the new update. Check for software updates in the Help menu in Kyma. Thanks!
Thanks so much for this - working great now. Much appreciated!
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Hi Jason,

Maybe the answer can be found in the Preferences Input - Output Delay?

answered Dec 12, 2021 by roland-kuit (Master) (3,350 points)
Hi Roland, thanks so much for your reply. I did indeed try lowering the Input-Output delay to 4.5ms, with no change in the issue. It seems to somehow be a delay 'within the patch', rather than between the patch and the outside world.
Hi Jason, thanks I will perform such a test tomorrow.
Do you use the rebuild legacy sound Compressive EQ or Stereo Compressive EQ?
If you'd like to test it, it might be best to use the .kym file provided at the link I put in the comment above. The chain starts with the Input, then progresses to an 'EqFilter' object followed by a 'Compressor dB' object. The mix knob then blends between the dry input and the output of the Compressor dB using a 'MultiChannelMixer' object. Thanks again for your interest and help :)
Hi Jason, our posts crossed each other. I see SC answered your question. I had that thought too in the above-mentioned legacy sound.
Yes the issue has been fixed now by SSC in the latest update. Thanks for your help Roland.
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