Very good dags. I like that approach. Just out of curiosity have you tried this with the intent of achieving my goal? How did it work out?
Based on your description I suspect you have done this with good results.
Hi mate
I set this dual fig-8 config up for a recording trial when I studied at SAE many years ago.
For the purposes of capturing a 'performance' it was fine, and I was able to use a little EQ on each channel to make the voice stand out
a little more from the guitar and some compression on each channel to smooth things out a little.
But as I said earlier, you're never going to be able to remove the guitar from the vocal mic or the vocal from the guitar mic.
The two are too close together to be able to effectively cancel out spill so you could never completely replace the vocal later on.
I have also used an
SM58 for vox and a standard cardioid condenser on guitar for a demo recorded in a semi-treated bedroom sized room with as much as possible of the 'blind' side of the condenser aimed at the singer (condenser a little way up the fretboard aimed at the soundhole and set at a height so that it is pointing down a little) OK, it's not an award-winning combination but it served its purpose
Something else to consider, most players will need to look at the fretboard of the guitar at some stage so using a horizontal baffle (shield) to try to isolate the guitar mic from the voice is going to be a nuisance to them.
I'm afraid that for complete isolation when you have the singer also playing the guitar, you're going to need to do overdubs, as others have also indicated.
Gaffer his/her mouth shut when they're recording the guitar part so that there's no chance of any vocals accidentally getting printed with the guitar
Hope you can find a solution that works for you, but don't be afraid of doing a second (or third) pass to record clean vocals over clean guitar. It doesn't take long and you'll appreciate having the flexibility of being able to do any processing to either channel without having any nasty spill to contend with.
Dags