Sound Mix EQ broken on macOS

Reproduce:

  • Create sound mix (like shown above)
  • Create sound class (like shown above) which applies effects
  • Set sounds you want to play to use this sound class
  • Play long sounds (like music)
  • Create blueprint to call Push Sound Mix Modifier (with created sound mix as parameter) on key press
  • Start game in PIE or otherwise
  • Press key

Result:

  • On macOS (tested on 10.11.6) all sounds of that sound class get silent with periodic audible artifacts sounding like “ticks”

Expected:

  • Effect (low pass filter in this case) gets applied to all sounds having sound class (like on Windows and Linux)

Note:

  • Tested on 4.14.3 and 4.13.2 which both have this issue.

Hey dgrieshofer,

Thanks for the clear and precise repro steps. I was able to confirm what you are reporting and have gone ahead and entered a bug report for the issue. You can track the report following the link below on our public issues tracker.

UE-41818

Once the issue has been addressed by our engineers the ticket will be updated and reflected in the public tracker. Let me know if you have further questions or need additional assistance. I will say that we will be rolling out major changes to our Audio Engine very soon, so this issue might be resolved with those new changes.

Cheers,