Hi there , I noticed nobody had answered you so I'll have a go. I find that if you combine both the two boys choirs on the first page of your choirs on the voices you get a lovely rich sound. If you select one on R1 and then the other on R2 and pan each in the opposite direction, also a fair amount of reverb usually large hall plus gives you a really rich choir backing. The add further add the gospel hum as well as your third voice. Hope this helps. David