If you want the choir in the
house mix and also just the choir to the recorder, then assign the inputs for the choir to one or two mixbuses (two if you want stereo for
house and/or record) and unselect the choir inputs from the going direct to stereo out (uncheck the "ST" on those input channels). Assign the mixbus(es) as "fixed" in mixbus setup settings. Then assign the mixbuses to output to "ST" (stereo left/right out") so you get it in the
house mix. You can now bring the master
fader for those choir mixbuses to a suitable position on the "Custom
Fader"
page for easy control over the choir.
Then you can also assign the choir mixbuses to whatever omni output you like. That way you only get the choir on those omni outs for the recording. Just think about the audio path/flow through the
desk from the inputs to the mixbuses to the masters.
I mixed a Christmas
Pageant last weekend with 24 wireless
headset for the choir this way. I assigned them into 4 mixbusses by choir part (
bass, tenor, alto, soprano) and mixes the choir in the
house mix using the mixbus masters on the customer
fader page. While I didn't separately record the choir in parts, I could have easily assigned the mixbuses to their own onmi outs for that purpose.
The LS9 is very flexible with the assignment of the 16 mixbusses. I was using 4 for
monitor/folback
send, 4 for choir part assignments/submix and 4 for effects (3 different reverbs and a delay). The custom
page was configured with the actor headsets (not choir), the 4 choir parts, the band/
orchestra, media inputs and effects sends (mixbus 13-16 masters) and returns (ST1-4).
The USB record feature is ok simple things, but I would not use it for anything where I required a quality recording. I use it for recording sound effects for show playback, or for a quick and dirty "he's what the show sounded like" for a band. But if you can record to a proper recording device then assigning am omni out to a mixbus and the inputs you want to that/those mixbus(es) then that going to work best in most circumstances.
In some ways it was easier to mix the show at that
venue with my LS9 than it was at my "home"
venue with Midas XL8 where we had the choir parts assigned to VCAs along with band sections,
orchestra, actors, media
etc. And I can lift the LS9 by myself
.