Can anyone make use of Niagara scratch dynamic input for audio using audio spectrum? I had once made it work in UE4 but since UE5 it does not do anything for me. Has something changed and was not documented?
Ermergerrd… I am finally seeing amplitude. So its a good chance my other math is just, bad.
Well i figured out the problem I am running into. In my game project I am using “LoadStreamLevel” node on start, which blocks pretty much everything as it loads and that seems to end the audio signal going into Niagara spectrum. I can still hear the audio but Niagara no longer gets input. I have no idea how to work around that 
New discovery… I seem to be having luck with setting the particle system performance option Auto Deactivate to false. On first load of the project it seems to work but is failing intermittently when restarting the level.
This might sound like it should have nothing to do with anything with what I am experiencing here, but… I am seeing much better results after creating primary data assets for my characters and loot items and getting everything into memory before the level starts.
In editor, things are still buggy (particles not starting with spectrum input). But in a packaged game everything seems to be working great. Previously i was not able to get this to work in a packaged game whatsoever. I’ll take that as a win 
Finally… I have a definitive answer to what I have been experiencing… Though all of the things I have tried have helped in the long run… The culprit was…
My Sound Device Drivers!!!
Switched to another sound device (after force updating the drivers, thanks Windows). And everything is working perfectly. In editor and in packaged game.
The problematic device was a Soundblaster Z SE. I switched to a Motu external device and i guess we will see what happens