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Topic: DIY PZM Microphone: parallel- or flush-mounting? (Read 5053 times) previous topic - next topic
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DIY PZM Microphone: parallel- or flush-mounting?

Hi all,

Currently I'm ordering some electret microphone capsules (Panasonic WM-61) and electronics to build a preamp for a pressure zone microphone, as they have some interesting advantages over normal microphones. However, there seem to be two possible mounting options: facing up (usually called a PZM) and facing down (usually called a boundary layer mic), see image below:



However,  the nomenclature is a little confusing: a boundary layer mic is using the pressure-zone for improving performance, and a PZM needs a hard surface (boundary) to behave well. So: is there actually any difference? I found some information indicating that they are the same. However, some state that a PZM has the advantage (over normal microphones) that they merge the direct sound with a reflection (which don't cancel because of the very short added waylength) which I can understand, but a flush-mounted microphone hasn't, as it doesn't grab any reflections of that surface. So, I was wondering: are these mounting options indeed similar performance wise?
Music: sounds arranged such that they construct feelings.

DIY PZM Microphone: parallel- or flush-mounting?

Reply #1 –
They are nearly identical in practice.  Actually, early mics with the original PZM designation all had the mic facing down. The advantage was that the capsule was somewhat protected that way.  An up-facing capsule is fully exposed to the cruel world. 

http://www.crownaudio.com/pdf/mics/discontinued_PZMs.pdf

Don't forget that the low frequency response is a function of the size of the boundary. 
 

DIY PZM Microphone: parallel- or flush-mounting?

Reply #2 –
Quote from: dc2bluelight on
Actually, early mics with the original PZM designation all had the mic facing down.

I thought all mics called PZM were facing down? Crown does make PCC's, which aren't, but they are a different matter  Anyway, thanks for the confirmation of that SoS-article


Quote from: dc2bluelight on
Don't forget that the low frequency response is a function of the size of the boundary.


Of course, I'll be using these lying flat on the floor or mounted to a wall.
Music: sounds arranged such that they construct feelings.