Audio Priority problems...

I'm hoping someone will have an answer to this, it's driving me insane... Here goes:-

Basically it's to do with priority and audio sources getting cut when there are a lot of players in-game. For example in one level I have an overall 2D source (an ambience) and 3D positioned environmental audio, when there are a few players in game, some 3D sources get muted. I understand that Unity can only handle 32 audio sources simultaneously and i've set various priority settings as to what I think is relative but still no joy!

It's driving me mad! Any ideas of settings?

Cheers, Jonny