Severe audio glitching and crackling with CPU overload warning

Bug Archive
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29

HI @ricardopeixoto , thanks for logging the bug. I’m afraid you’re hitting the limits of the Synth design and CPU warnings are there to communicate this.

We support up to maximum 8 voices, but not all combinations of synth engines will perform equally. We could limit the number of voices further and always have optimal performance but instead we introduced CPU high (yellow) warning (just like a computer DAW) to indicate you need to take few steps back… because when you hit CPU overload warning (red) you will get audio dropouts.

PMD and GRAIN are particularly CPU hungry and that’s why they are limited to 2 and 1 voices respectively. GRAIN is special because it’s paraphonic: that means it can effectively play unlimited number of voices which are equivalent to its Density and Grain Size, so those two parameters will affect CPU load also. On the PMD synth engine Array parameter will also have a big impact on performance.

So if you are reaching yellow or red CPU warning, we recommend the following:

  • GRAIN: adjust Grain Size and especially Density parameter to a lower value
  • PMD: adjust Array parameter or lower the voice count
  • If you want to keep higher values of the previous two synth engines because you “need that particular sound”, then lower the voice count on the 3rd synth engine loaded

These are the constraints of the current Synth design and I hope this explanation helps with understanding how to use it without running into performance issues.

4 Likes
31

Hi @miropoly

Thanks for getting back to this.
I’m a glass half-full guy so I prefer it being a CPU limitation than some other serious hardware issue for ex.
I personally don’t mind limitations, but, for the sake of preventing user frustrations, you probably should’ve been more clear regarding them. I’m sure you’ll have more people reporting this issue once they start designing their own Scenes.
I’m fine with one voice PMD and one voice GRAINS per synth tbh. They sound big enough as it is :slight_smile:
But I still hope that some type of optimization is possible, to take the sonic possibilities even further and avoid the occasional noise-scare that I’m sure will happen when we get carried away with the sound design and performance.
Again, I’m loving the sound and interface on this thing.
You made a really lovely instrument.

4 Likes
32

Hi @ricardopeixoto , thanks for your feedback and kind words. We appreciate it and will take it into consideration when designing new products.

33

For more information you can read the official post about this topic @here: Synth CPU Usage Info

34

Hi, all, I’ve got a fresh Synth (one week) and have been running it through the paces. I noticed a similar bug: audio sounding like it’s running through a bit rate reduction, pops and clicks, etc. At first I thought it was a sync issue from some hardware I have, but now I realise it’s just the Polyend Synth. This is with running one sound (“Resonant Lift”) playing one note. All I have to do is hold that note and about 10 seconds later it starts to distort then cut out completely. Then a minute later, I can do the exact same moves, playing no other parts of the Synth, and it will be fine for about a minute or two. Some days it works flawlessly; some days many flaws. I find myself having to track in sounds and piece together times it wasn’t crapping out. It’s a frustrating experience that has made me slightly regret my purchase. From what I can tell, this isn’t an issue of user error or expecting more out of the machine than could normally be expected. It’s a proper bug that needs resolving.

35

Lower your volumes to each engine when this happens and see if that helps. I have noticed if you run volume too high it can cause this as well.

36

Thank you, yes, that was where I started. Seems to still do the same whether I lower the overall volume and/or the individual Engine volumes.

37

I should add (as this is my field of expertise): the distortion sounds like the bit rate of the DA converters is dropping from 24 (or maybe 16?) down to 2 to 4 bit then recovering. Similar to what one would hear using Ableton’s “Redux” plugin.

38

I’m still noticing some minor pops here and there, for example if I have a couple of notes held on one synth and I’m browsing for a preset on another I sometimes get loud pops when I scroll.
It’s quite annoying if you’re planning on switching presets mid performance.

2 Likes
39

Hi @charlesreeves , thanks for your message and sorry you’re experiencing issues with the Synth. Does the CPU warning appear when you hear the “bit rate reduction, pops and clicks” ?

40

The sync issue is a separate problem and we plan to fix it: Synced Delay clicking/stuttering when receiving external MIDI clock

41

there’s no CPU warning of any kind. The unit will sometimes flash (in the upper left corner of the screen) the word “saving”, but that seems to be at various times unrelated to the sound anomalies

42

for clarity, by “sync issue” I meant between my console’s Dante card and my UAD interfaces (as in sample rate incongruence).

43

In this case it’s unrelated to this topic. Please open a separate Bug following How to report bugs and we’ll try to help you out. Thanks for your support!