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PZM Mic Advice. Wall Adhesive

Discussion in 'Recording' started by Suntower, Dec 10, 2011.

  1. Suntower

    Suntower Active Member

    Apr 1, 2005
    Winter: Seattle, Summer: Dublin
    Home Page:

    After 15 years in the garage, I just found an old pair of Radio Shack PZM mics I had forgotten about. I forget the details, but I seem to recall that they were like $30 ea and this version was considered -very- close to the pricey Crown models. I must've done -some- sort of wiring on the jack because they now have XLR connectors. I must've experimented with them a few times, not had a clue what to do and forgot about 'em.

    Anyhoo, -now- one works and the other does not. So I took the one that works and stuck it to the wall in my drum room (aka 10 x 12' untreated bedroom.) I figured that is the biggest 'boundary' so WTF.

    WOW. This is an -amazing- sound. It's dreadful by itself, but as a room mic, it makes the dry sound of the close mics -really- come to life by adding almost a SUBWOOFER bottom. Makes me wish the other one still worked!

    So questions...
    1. I see they don't make this thing anymore. Is it worth considering another model for 'stereo' room mics? Do they need to be 'matched' or are they all pretty much the same? I see even the cheap-o ones are now much more expensive than what I paid for the RS.

    2. Is there a strategy for -placement-? I tried it on two different walls and it sounds pretty much the same---at least as a background mic.

    3. Is there an adhesive I can use to mount it to the wall that will not remove the paint? I found that if it's not in -firm- contact with the wall, it creates a terrible rattle @ certain frequencies, but I can't mess up the wall cosmetically.


  2. RemyRAD

    RemyRAD Guest

    Sep 26, 2005
    These are great microphones. Yes, they sound like their $375 Crown siblings. There ain't much to go bad in these things. They're almost impossible to kill. The battery box has a tiny transformer in it. Battery contacts also get corroded. Utilizing a standard OHM meter, open the battery box and start tracing the wires out to the connector for continuity. Check the transformer and make sure it doesn't have an open circuit but a low value resistance. If the microphone element has crapped out, you can get another one from Radio Shaft for a couple of dollars. It's just this little piece of crap from Taiwan that's the same as the one that's in there. Which is also the same one in the $375 Crown version albeit untested & uncalibrated but that's it. Since you have a working one, you could take the plunge and try swapping parts back and forth from the nonworking to the working. This may be a corker way to troubleshoot. It may also be possible that somehow, someone messed up the wiring on the XLR on the nonworking one? Shield to pin one. And just match the White & red as it is wired on the other XLR.

    To gain better performance from this microphone, Eveready makes a battery that is actually 6 VOLTS. It's 1/2 the size of a AA, so you need 2 for each microphone. Make sure you remove them after every use. They won't last long even if you have the off switch, switched to off. And the batteries are quite costly. This will improve output level and lower noise.

    They make great overhead microphones, for drums, if you tape them to your ceiling with duct tape. Unfortunately, you could frequently pull the pains away from the plasterboard that way, same for the walls. But 3M has made some new wall-mounted adhesives, guaranteed not to destroy the surface or pull off the paint. They work equally well when placed on the wall behind the drummer on each side of him. Conversely, you can also place them on the floor on either side of the drum kit which I have done many times.

    Given only one, you may want to use that strictly for bass drum. It makes a great bass drum microphone. Just throw the pillow in the bass drum and put the microphone on top of it. I've recorded a lot of drums that way & utilizing 3 of them for left-right-bass drum. They sound incredible. So go check out some Radio Shaft condenser microphone capsules generally available under $2. That is if the capsule has gone bad. So a good reason to swap it with the other battery box. That would certainly lessen what might be wrong with it by 50%. And that costs nothing.

    I still love my 8
    Mx. Remy Ann David
  3. Davedog

    Davedog Distinguished Member

    Dec 10, 2001
    Pacific NW
    Glue them to a piece of Lexan or plexiglass and drill a couple of mounting holes in it to screw to the wall or the ceiling. I put mine on an adjustable mount that screwed onto a mic stand. You could then put them anywhere. I had four of them all mounted to plexi plates about a foot square. Two with the mic stand mount and the other two I used to just lay them on the floor where ever I wanted to add their sound. Worked like a charm under the grand piano combined with the piano mics over the top. The ambience that a PZM mic adds cant be duplicated. There several companies that make boundary mics these days, but for the price the Radio Jacks were incredible.
  4. RemyRAD

    RemyRAD Guest

    Sep 26, 2005
    One of the fascinating things about the Pressure Zone Microphones is that their bass response is a factor of how large the boundary is that they are sitting upon. The larger the boundary, the more low frequencies it will pick up. Where Dave indicated he had his on 1 ft.² Plexiglas panels were actually recommendations from the manufacturer. This one square foot panel only allows low frequency response down to approximately 150 Hz. This can be very beneficial sounding since a wall or a floor, ceiling could deliver too much low-end mud. I've mounted these things on similar plywood panels onto microphones stands as well. But onstage, that can look extremely unsightly and so, Plexiglas is more aesthetically pleasing to look at/through. Yet there is a small difference in tonality between Wood & Plexiglas. Plexiglas in and by itself is quite dense but also more reflective than the more woody sound of wood.

    The Woody Pecker show. Now at a stage near you. Rated P.
    Mx. Remy Ann David

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