Thats so awesome, seems like nobody ever takes any of the solid advise thats given around here, but you did! Way to go! I'll try to give you some decent pointers and hopefully others will chime in as well.
Have you ever done live sound? Cause thats basically where you're at now,. The difference being that you'll be listening to your soundboard mix through headphones instead of on stage monitors! This is actually much easier in many ways as you wont have to deal with feedback/stage monitors. What kind of Headphones are you using? If the bands not too loud a nice set of flat response closed back cans will be needed. You might need to monitor from a different room. I've also used hearing protection earmuffs over top of in ear monitors (earbuds),. but bass is tricky on those but it can be done.
You still have a couple of things to watch out for.
Room. What kinda room are we talkin bout here. dimensions (LxWxH)? vaulted ceilings? windows? doors? closets? treatment available(anybody have access to some cheap/free fiberglass insulation, pink fluff will do)? will you be mixing in this room also? This info is needed to start planning placement, and to determine options for dealing with room noise.
Drums. What kinda percussion are we talking about here? Big kit, jazz kit,. is the drummer more of a light handed minimalist,. or more the get people dancin drummer? If your dedicated to tracking everything live with no overdubs drums are still a primary concern,. seperating and isolating them from other instrumentation will be key in your ability to get the mix to the level your probably looking for.
mics/mic placement. Hopefully you've heard the band before and are familier with there work. which mic to use and thier placement in this situation should largely be dictated by how the band wants to represent themselves,. When they play live do they ever plug in? or do they just play small places where they can be heard acoustically with maybe one vocal mic(like a restaraunt or similar). Do any of the instruments take solos? These questions might give you insight into how the band might want to highlight certain parts of thier sound they think are worth amplifing(or in this case, micing individually). That being said, your stereo mics will pic EVERYTHING up. I'm guessing the drums and accordian will be the things that stick out. Provided everything is in the same room I'd stick the accordian close to the drums, both should be futher away from the stereo mics then the rest of the band. If the accordian is featured you could either A: give it a mic, B: plug it in to the mixer direct,. probably into an guitar/instrument input, not sure what your mixer has. If its not featured the drum and stereo mics will pick it up fine,. You'll probably want to Hi-pass filter every channel on the board your using.
The vocals want to be captured by the c1, and thats probably what its sole purpose should be. I would definatly have it set so the vocalist all have close access to it,. you should probably get/make a pop screen for it,. it can serve dual purpose as pop filter/ general area target for the singers so they know to get close to it, but are also kept away from the mic so as to not overload it. If they are not monitoring on headphones this will help keep levels on that mic in check a little.
Prep,. Before you do anything else plug everything in,. set some levels. make sure your software is getting a signal and hit that record button,. go talk/sing/play to all those mics,. and then listen to what you recorded. Now you know what kind of recording quality your dealing with,. you know stuff works,. and you have a better idea of what to expect from your mics. Hopefully you can do all this in the actual recording space and you'll get an idea of what the room sounds like as well.
Also,.Your using protools! I bet your mac could probably handle a few more tracks. You've got enough tools there to kick things up a notch. If you go back and let the vocalist do another take while monitoring on headphones you could mix them seperatly and make them shine. Same thing with other instruments. This takes more time, effort, and players that know thier material well and have good time. But its very worth it,. and will take the recording to increasingly more professional results. If time is the main concern, Limit the session to 2-3 songs. As a performer I'd much rather have a quality 3 song demo than a lesser quality 6 song EP. But that may be more of a concern for the band to deal with. I'd give them the option anyway.