Wwise crossfade distortion/scratching

This is probably not an SDK-related issue, I’m putting it here anyway because I found nothing on it anywhere in the www.
I’m getting some clearly audible distortion/scratching in my engine loops at the crossfade locations that I’m unable to troubleshoot.
Here’s a short video showing the issue:

I think I’ve got the fundamental tones and the math right.
Things I tried to resolve that crackling without success:

  • Using different formats for the source wavs (24b/96Khz, 16b/48Khz and so forth)
  • Finetuning the pitch by ear (I tried every pitch cent within range until the loops where clearly out of tune).
  • Increasing/decreasing the blend range
  • Tried different crossfade curves

Is anyone having an idea what’s the cause of this distortion, considering that adjusting the pitch doesn’t fix the problem?

Hmm, I can’t believe that I’m the only one who ever came across this kind of problems.

Hello @Mathias !

What you are hearing is not exactly a saturation.
If it were, you should be able to see it in your master audio bus meter.

Our sound team thinks it is more an overlap issue of your two different sounds. As the dynamic range of your source sounds are quite high, it indeed doesn’t overlap very well. They would recommand to reduce the Blend Time, but as I understood this didn’t help you. Maybe you could also try to tweak your source sounds ( adding an EQ or some dynamic effects ).

If this answer doesn’t help, I suggest you to seek for help on the Wwise forums.



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Thanks much @GentleLynx!
Indeed, the levels go from -24db @800rpm up to -8 @2000rpm.
I added some compression (a lot of compression actually) in Cubase now prior to exporting the loops what definitely helps a bit, though that’s not the final fix yet.
I’ll try to unify the loops with the EQ a bit to see if that adds to the solution.
Thanks much for your hints!

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A problem that also affects your sound here is the timing of each cylinder strike - they are offset/out of phase with each other. Try adjusting the timing/loop points of each sample to remedy this.

“Phasing” also can occur in multi-engine aircraft, and is quite a frustrating artifact that plagues a lot of aircraft in MSFS, especially if special care is not given to ensuring these loop points are unique per-engine and use different takes (if possible).

Please take a look at this video, which very briefly describes phase shifting and the problems it can cause when dealing with audio processing and mixing, I hope it helps! : https://www.youtube.com/watch?v=1pJOkhPTpLo

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Thanks for the suggestion, Tyler!
Hmmm, that scratchy sound is not what I’d typically associate with an out-of-phase effect. You would get some frequency cancellation but not this addition of what sounds like digital distortion (in lack of a better term).
Anyway, I’ll pick up on your suggestion and try to catch the same stroke cycle for each loop. Sounds sensible.