this is an interesting topic,i'm begining to think that volume may depend on where you are calling.here in the east where the blocks of woods and fields are relitivly small,to much volume will deffinetly run them off.i believe its becouse when you go in to call there fairly close.in the wide open expances of the mid west and west volume may not be as critacal.theres no dought though,if i crank my call box or blow a hand call unmuffled(at least on the first call series)nothing is going to responed.of caurse most of the coyotes(and fox) that i chase around are highly educated,this could be a major factor also.but i still believe a caller won't go wrong by starting off at lower volume then if nothing responeds you can crank it up some.