Mods: This may be more suitable for Cafe Society since it involves the Theater. Feel free to move it as appropriate.
I run sound for a community theater group in my little town. We have been using borrowed 12 year old floor mics for our non live music/non signing productions and they don’t work very well. The actors have to be looking almost directly at, and be within a few feet of, one of the 5 floor mics at the front of the stage. If they are turned away, or happen to be at the back of the stage, their voices aren’t picked up at all. I can’t really crank of the mics or I will start to get feedback.
I have used body mics before, but that was for musicals, as opposed to comedies or dramas without any singing. One advantage is that the actor can be anywhere on the stage, facing any direction, and the body mics will pic up their voice. One disadvantage is that someone, likely me, will have to keep track of a dozen actors who may be constant entering and exiting the stage to make sure their mic is either up or down as appropriate. If you add in the various sound effects and music I have to play it can easily become overwhelming.
Someone told one of our directors that we should be using PZM mics (pressure zone microphones) for our application, which I have never used before. They look similar to the floor mics we have been using.
What are the advantages of PZM microphones over regular floor mics and body mics? Let’s assume for this exercise that money is no object.
PZM or more accurately “boundary” mics pick up the vibrations on any surface.
I have no experience in theater. What surface would they be mounted on? Possibly if you used them on side walls, perhaps in addition to floor mics. (For anyone who doesn’t know, floor mics are positioned at the bottom front edge of the stage, pointing into the stage area).
Since you’re asking for opinions, this probably belongs in IMHO.
Try googling. You might find some info in these PDFs:
The Shure guide shows PZMs mounted to the stage floor at the front. Seems to me that’d pick up footfalls REALLY loudly; perhaps actors have to practice with them and learn what not to do on stage.
Money is no object? And this is community theater? :dubious: When tech directors dream, every summer stock production gets to work with a full fly loft, intellibeams and mic cables that are more wire than gaff tape.
Two PZM mics at the front of the stage ought to serve you well. Any chance you can borrow a couple to mess with before buying anything?
“Don’t step on them” is about all the actors need to know. Some glow tape around them will be useful to make their locations more obvious to the oblivious. They’re surprisingly good at rejecting noise and vibrations in whatever they’re sitting on. Not perfect, mind you, but better than an ordinary mic on the floor. My desk phone has a stand-alone speakerphone unit that uses a PZM mic, and I can drum my fingers on the desk and it doesn’t pick up the noise, but it’s got good “reach” so I can be speaking ten feet away and heard clearly.
Would you be using these mikes for recording or for the PA system? They are kind of an ultimate of non-directional mikes. I’d think you’d have trouble using them in a PA system as they’ll pick up any ambient noise and pump it into the PA as well.
I used to work in radio theater, and the only thing we used them for to to collect audience noise. They were too non-discriminating enough to use for anything else.
No kidding! I wouldn’t have guessed, but that’s great. I’ve never had a need for one, and haven’t ever had one to fiddle with.
Since they’d be picking up vibrations on the stage floor, they’d get sound located on the stage significantly higher than from the audience. If I understand the theory correctly, you can put them anywhere on a surface and they pick up the sound hitting that surface with only slight regard for where that sound hits the surface. If so, that means they’d cover the whole stage quite well, so audience and pit sound would be attenuated based on distance from the stage.
Evidently I was mistaken about how boundary mikes work. They don’t pick up the vibration of the boundary. Instead, they work based on the air pressure differential at the boundary. Furthermore, they can be cardioid, so as to minimize picking up PA feedback, audience noise, and pit music.
According to the Shure guide, either boundary mics or overheads work best with trained actors who know how to project their voices, for weak voices you can easily run into feedback issues. It recommends wireless mics for those cases. Yeah, I bet it’s a chore keeping up with those!
Unfortunately, still no answer to the OP’s question, which is benefits of boundary mikes over overheads or floor mikes.
BTW, if the “PZM” mikes you’re considering “look like the floor mics we’ve been using,” it’s likely that you are using boundary mikes and just don’t realize it.
You can put something sound-absorbent like a roll of carpet or chunk of foam “behind” the mic to reduce pickup of the orchestra, audience or PA, if you’re stuck with omnis or if a cardioid version isn’t rejecting quite well enough to avoid feedback.
Of course, since money is no object for the OP, they can also add a feedback eliminator to the house PA.
