In my professional life, about 90% of the time, when there is a choir with instruments- from small ensemble to full orchestra- the choir is behind the instruments on risers. To my main pair, the choir is less 'close' and detailed than the instruments because it is quite a bit further from the mains. Besides this, the choir is often partially or completely drowned out by the orch (Beethoven's 9th, anyone?) I find this is often a problem. My current solution: have a pair of mics on the choir to add diction when necessary, and to add volume when the orch gets way too loud. Unfortunately, some conductors dislike this solution because when one turns up the choir mics, the mics 'select' the choir members closest to the mics. Placing more choir mics is usually impractical unless there is time to hang them all- and many halls have no way to hang the choir mics anyway. That many floor stands is almost always impossible due to space restrictions. I have a particular conductor who so dislikes the 'selected voices' effect he hears that he disallows choir mics at all, leaving the mains to pick up choir as best they can. He does not mind the more distant sound (indeed, it is not always a problem). But our next show is a Bach Mass in B minor, and there are places that I fear the choir will be buried deeply. BTW: I love the sound of the choir on one side of the stage and the orch on the other. I was skeptical at first, imagining the weird wide stereo effect, but I did it on a Bach St John Mass and it was actually pretty subtle! Another solution is splitting the choir hard L/R and having them stand on either side of the orch. But I digress. The issue is the typical staging: choir behind orch. Thoughts?