Simple solution: return the 4 channel mixer, and exchange it for a small 6 or 8 channel. Use this new mixer as a sub mixer for drums, vocals, whatever, and plug a mono send from it into any channel of the yamaha.
Then with the 20 lines from your snake: 15 direct to the yamaha, and the other 5 into your new 6 (or more) channel mixer (hopefully not a Behringer)
If it is too late to return the 4 channel mixer, then just keep it as an aquarium decoration, and buy a small 6 channel mixer.
I am hoping you have a sense of humor, BTW.
Lol. i do have a sense of humor. The main reason i bought the behringer was because i got a stupid good deal on it, (like 35 bucks) and i needed something to allow me to practice at home without the annoying buzz from an un-grounded amp, as i live in a REALLY old house with one grounded outlet in the whole place, which is upstairs.
Then i started thinking about the church board, and went from there....
And 5stringfool, that channel IS in fact in use, as the stream channel from the mother church.
