Hello Rob and welcome to the Cow Audio Forum.
As Robert suggests, an omni will make things worse.
A great deal depends on the size of the room, the acoustics of the room and how far apart the twelve people will be seated.
Also, a great deal depends on your or your client’s expectations.
You say the presenters will be using handheld wireless mics. What will the receivers be feeding?
The easiest solution would be to have one or two wireless handheld mics that are passed among the 12 people so their voices can be recorded. Levels may vary considerably from person to person. You’re pretty past the level at which one person can do this shoot properly. A professional location audio person with the right gear is your best bet. Not cheap, but welcome to the next level of your business as a shooter!!
Bear in mind that when you report this to your client, he or she may say, “No. Too expensive!!” Your answer to which should be, “Well, I can not guarantee that you will like the quality of the finished product. We are fighting the laws of physics. That’s always a losing battle.”
OTOH, if their expectations are very low, it might not be what a pro wants to hear, but it might be OK for them.
Regards,
Ty Ford
Cow Audio Forum Leader
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