When attaching 3 or more Spectral Analysis Delegates to the same Submix, some delegates start returning only zero values. If this is a known limitation of Spectral Analysis Delegates, we should probably note this in the tooltips somewhere.

Steps to Reproduce
  • Create a Submix asset (right-click on the Content Browser and go to Sounds->Mix->Submix)
  • ¬†Place a Sound Wave in your level, and ensure it is set to auto-play
  • Go to the Sound Wave's settings, and set its Base Submix to the Submix you created in Step 1
  • In your Level Blueprint, create a Sound Submix Object Reference variable, and make it's default value the Submix you created in Step 1
  • Add the function Add Spectral Analysis Delegate to your Level Blueprint, attach it to BeginPlay, and make the Submix variable it's target
  • Drag off of the In Band Settings field on the Add Spectral Analysis Delegate and promote it to a variable. Compile the Blueprint, then add an entry to the variable's default value
  • Drag off the On Submix Spectral Analysis BP field on the Add Spectral Analysis Delegate, and select "Add Custom Event"
  • On the new Custom Event, put the magnitudes through a For Each loop and print each one. It may be worth making the text a distinct color to distinguish this from the output of other spectral analysis delegates
  • Add a new Spectral Analysis Delegate and repeat all of the above steps for the new Delegate.
  • Play the game, and notice that both Spectral Analysis Delegates are consistently returning non-zero values
  • Repeat the above steps for yet another Spectral Analysis Delegate, and play the game

Expected Results:

  • The outputs of the Spectral Analysis Delegates should have reasonable values

Actual Result:

  • The output of the first Spectral Analysis Delegate is now a solid stream of zeros, despite measuring the same frequency it was before the third delegate was added

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ComponentUE - Audio - Submixes
Target Fix5.1
Fix Commit22359106
Main Commit22366534
Release Commit22359106
CreatedAug 19, 2022
ResolvedOct 5, 2022
UpdatedNov 2, 2022