Here's my problem:
I'm going to be taping a local Jr. High band/concert in their Gym. Obviously, I'd like to get as good a sound quality as possible, and of course, there are obviously lots of very significant problems that arise.
My equipment list: 1 ea on-board mic (XL2) which I'll probably disable.
1 ea Sennheiser wireless Lav Mic, which'll probably end up on the Teacher/Conductor

OK...
First off, I obviously need a couple more mic's...I plan on hanging 'em high ... In an ideal world, I'd probably use 4-5 mic's and remotely mic separate areas, but realistically, I'm thinking of buying a couple mic's and use em Left-right over the band towards the front of the group. I don't have a lot of bucks in this for the budget, but should this be with omni, directional, or what kind of Mic's? What about placement??? In a practical world, how would you mic this with 2+1 mics (the 1 being on the conductor...)

What about Echo...echo...echo...?
While the band will be plaing to a packed house, and people will tend to absorb much of the bad sound, besides throwing blankets everywhere, any thoughts on controlling echo?

Bill,
Take a look at this thread:
http://www.dvinfo.net/conf/showthread.php?t=74830

Lots of good suggestions there.

Regards,
Jerry

Well, a band in a gym is challenging even if the gym is full of people.

Your starting point should probably be a stereo pair or a stereo mic fairly close to and above the conductor. The idea here is that the closer you are to the band, the more "direct" the sound will be.

This could be flown, or on a tall stand.

You don't want it to be real high, you want the sound of the band, not the sound of the room. You can't put enough people in most gyms to positively affect the sound.

See if you can get in during a rehearsal in the gym, and experiment with mic placement. You might start with 6 feet behind and 4 feet above the conductor and see what that sounds like.

Mic types - I've had good results with small diaphram cardoid condensors in an ORTF configuration (about 7 in inches apart, angled at 110 degrees). Other people like x-y (right on top of each other, angled 90 degrees). The thread referenced above includes some information on a-b, which I think is not a good choice in a gym but is fine in a concert hall. There are also some x-y microphones with the mic elements are in one mic body.

You'll want a mixer, pan the wireless center, and be sure to turn it down after the announcements.

Here is a nice reference on stereo micing:
http://www.oade.com/Tapers_Section/faq-mic.html

Another one:
http://www.schoeps.de/PDFs/stereo-recording-techniques-e.pdf

And some older threads:
http://www.dvinfo.net/conf/showthread.php?t=58833&highlight=stereo+microphone
http://www.dvinfo.net/conf/showthread.php?t=67276&highlight=stereo+microphone

I would see if you can rent a pair of Earthworks cardioid mics and place them in a coincident stereo pair above the conductor, either on a tall stand or flown. I recorded a full high school band in a gym with the audience on only one side. The recording was much less reverberent than listening live. I was very impressed with the mics. You will need to protect them from air conditioner breezes and shockmounts like AT8415's are also helpful.
If you can't access any Earthworks mics, then high-quality choir-type hanging mics would be my next choice. AT and Shure make many models. Remember that very-small-diaphragm full-range mics are intended for this purpose.
Again I'd go for a coincident or near coincident pair of cardioids located about 15 feet high and angled down to cover the group.
You can add other mics to cover specific or quieter but important elements.