Creating my own reverbzone; routing audio from multiple audio sources to one

Hey everyone,

I want to create my own reverb zone, because I've noticed, with multiple reverb zones, Unity still routes it through one filter; the one the listener's currently in (most probably to save resources).
So say if an AI fires a gun in a cave, and it's in the cave reverb zone, while I would be outside, having the forest reverb, the gun sound would be sounding as though it was outside because the AudioListener is in the outside reverb zone.

[Cut]

Edit: That was fairly simple. Copying data from a source's OnAudioFilterRead() to the reverb script, and using the combined data in the reverb script's OnAudioFilterRead()