Bruce Watson
Veteran
An inexpensive PZM microphone in the center.
Hey, it is what it is.
Yes. A boundary mic is perhaps the OP's best bet. Doesn't have to be cheap, be sure it is omni. Only need one, on the floor, center of the circle.
This will perform poorly up to maybe almost adequate, but perhaps less poorly than other options. The OP would be well advised to get a micpre with a good amount of clean gain. A DR-40 won't likely cut it. A Sound Devices MixPre-D probably would be sufficient.
The OP might want to consider renting instead of buy/sell. A decent rental house could probably make better suggestions on micpres/recorders.
