A boundary layer mic, also called a PZM or Pressure Zone mic, is a different critter altogether from the usual omni,cardioid, hyper, etc, pickup pattern descriptions. It often resembles a hocky puck resting on a flat surfaced pressure plate such as a table top. When sound strikes a flat surface, a wave of high pressure air builds up running parallel to the surface. The mic responds to this pressure wave while effectively ignoring sound waves hitting it directly from above. The resulting pickup pattern resembles a hemispheric bubble resting on the pressure plate, in this case the table top. This has tha advantage of picking up voices around the table well while somewhat reducing response to room relfections since the reflected sound from the walls is so much weaker than the direct sound due to the much longer travel distance. The pressure buildup on the surface of the boundary plate adds about 6dB of effective gain to the basic mic capsule sensitivity for the direct sound but only about 3dB gain for the diffuse room sound, giving a more relaxed working distance from the speaker and further helping it dominate over the reflections coming off the walls. PZMs are frequently used for press conferences, round table discussiuons, teleconferencing, and when mounted at the stage lip or on positionable 4 to 8 foot square panels, in orchestral and stage drama recording. Two or three PZMs on the table top, controlled by an automixer that only pots up the mic closest to the speaker of the moment, would give you good coverage of the group seated around the table while minimizing the effects of the room reflections. Of course the other advice to get some sound absorbing materials into the room as much as is possible also still holds true.
Its funny how everyone wants to be right. I have shot a large number of people in smaller hard rooms with dynamic mics (sennheiser 835s and 845s) and it has worked out fine. I have done it, not theoretically, but I have actually set them up in this manner. I did audio since 1995, did it full time until 2007. And not just this once a month crap either, 5-6 days a week. A dynamic mic can work fine at distances within 10 feet depending on room characteristics. Typically hanging them overhead, over a conference table, distances are only going to be 5-7 feet max.
I'm not saying its the perfect solution. And different dynamic mics have differnt patterns on them. But for a cheap and quick "I need audio that is going to not reverberate and slap back like a condenser in a brick bathroom" scenario, it can work. It's not ideal. But it can work.
We're not talking about a 40 x 40 room here. We are talking about a 15x15 room (as per the op) that has hard surfaces and is very "live". In my experience, a dynamic mic can help cut down on the natural reverberation compared to a condenser.
Try it sometime, then tell me it's ridiculous.
You're absolutely right. I really don't understand why anyone in this business bothers wiring people up or following someone with a boom overhead scraping the edge ofIts funny how everyone wants to be right. I have shot a large number of people in smaller hard rooms with dynamic mics (sennheiser 835s and 845s) and it has worked out fine. I have done it, not theoretically, but I have actually set them up in this manner. I did audio since 1995, did it full time until 2007. And not just this once a month crap either, 5-6 days a week. A dynamic mic can work fine at distances within 10 feet depending on room characteristics. Typically hanging them overhead, over a conference table, distances are only going to be 5-7 feet max.
I'm not saying its the perfect solution. And different dynamic mics have differnt patterns on them. But for a cheap and quick "I need audio that is going to not reverberate and slap back like a condenser in a brick bathroom" scenario, it can work. It's not ideal. But it can work.
We're not talking about a 40 x 40 room here. We are talking about a 15x15 room (as per the op) that has hard surfaces and is very "live". In my experience, a dynamic mic can help cut down on the natural reverberation compared to a condenser.
Try it sometime, then tell me it's ridiculous.
Jump to the conclusion? I've personally recorded MANY DOZENS of round table discussions and my actual PREFERENCE is using stick mic's in front of people.
