Passive Sound Mixes - volume threshold

So in the docs it says “Passive Sound Mixes are Sound Mixes (see below) that are passively activated whenever any sounds of that particular class are playing louder than a specified threshold.” and in the Sound Class you can specify a number. But what does this number actually relate to ?

Let’s say for ducking dialogue example that npc dialogue up close plays back at its max volume 1.0 when they’re standing next to you, and 0.5 when their a given distance away due to attenuation over distance. What do I set the volume threshold to ? As I want the ducking mix to occur when it’s 0.5, (since I want the player to hear the dialogue) but not at 1.0 (since we then don’t need to duck). It seems to work in the opposite way to that which might be useful ?

I’m likely misunderstanding this but can anyone give me and example case to make this a bit clearer ?
Cheers !

Unless I’m misunderstanding to get the 1.0 to 0.5 behaviors you’ll want to apply an attenuation behavior to the sound.

The Passive Sound Mixes are intended to be a way of automatically applying a Sound Mix when something is occurring.

So for example, if you wanted to make your ambient sounds quieter while a dialogue line is playing, in the Dialogue SoundClass you’d add a Passive Sound Mix that ducks the volume on the Ambient Sound Class.

Another example of how this could be used is if the SoundClass related to a particular enemies ambient sound is loud enough (the threshold) we pitch shift the whole audio mix.

Thanks Marc,
I’m not sure I get the pitch shift usage case (that would be a pretty radical approach!) but I think I understand the system.

So for dialogue soundclass for example - whenever I play (i.e. my volume threshold is above 0.0) then instigate a soundmix that ducks all ambient sounds. This is useful but this effect is going to occur every time dialogue plays, even when it’s not required, which is not very subtle. When mixing we usually want to change a mix to make sure something is heard, i.e. we don’t need to instigate the ducking soundmix if dialogue is at 1.0, but we do if it’s at 0.5 (because the NPC is at a distance from me and so I might not hear them). At the moment the volume threshold works in the opposite way to this - ‘if I’m louder than X then apply soundmix’, whereas what would also be useful would be ‘if I’m quieter than x then apply soundmix’

The only application I can see of the current volume threshold approach would be some kind of basic HDR audio system i.e. I’m a loud sound playing, so duck all other sounds to give me more headroom. Maybe that’s what it was intended for, but it seems a shame that we can’t also have a system that’s more useful for ‘this sound needs to be heard’ i.e. what we have now is a ‘Max’ threshold, but it would also be useful to also have a ‘min’.

Hope that makes sense !
Thanks again.

The pitch shifting may have been a bad description. I’m just the programmer who writes these things, don’t much get to using them :slight_smile:

I think in your dialogue situation you are going to be better served with an attenuation falloff that uses the LogReverse (Sound Attenuation in Unreal Engine | Unreal Engine 5.1 Documentation).

You are right that the design of the system was very much a basic HDR implementation, however, having a Max threshold is a good idea to provide the system additional flexibility. I will be adding that in.

No worries - could work for bullet time though :slight_smile:
I’ll have a play around with using it in HDR mode among other things - but yes it would be great to have that addition.

Hi again,
I see that this has been implemented - great !
Having spent a while trying to understand it I include below some guidelines for others looking into this who may come across this thread. If any staff are able to take a look and confirm that my understanding is correct that would be good.