Boundary layer mics - reception success

[Philip Howells]

This thread starts with the fact that, unsurprisingly, many morning dress rental companies commission inexpensively tailored suits with maybe one or no inside pockets in the coat. The result is that the radio mic transmitter is clipped to the men's trouser waistbands. Often during the Summer the toastmaster or maitre d'hotel at the wedding breakfast will announce that the bride has given permission for the men to remove their jackets.

Although I always ask if the speakers are going to remove their jackets and explain why, inevitably the removal of jackets means some microphone cables are stretch-tested.

We decided to look for a solution and finally decided to try boundary layer microphones plugged into and powered by (they require phantom power) our Audio RMS radio microphone transmitters. First wedding was last Saturday.

The results are excellent. We purchased three AT851RW microphones which are white and insulated against mobile telephone RFI. We had to butcher one of the supplied white cables to give us the range of connectors required (the output from the mic is a miniature XLR, the Audio RMS transmitters use 6-pin Lemos) Modification to the phantom power element meant we had to include a full-size XLR junction in the middle but this also means we can use the microphones direct into a phantom-powered desk or camera if necessary.

Finally, my wife made small white cloth covers for the radio transmitters which we fastened to the table with white gaffer tape.

We miked the groom, bride's father and best man in this fashion and the result - in a notoriously tall, domed room with a fearsome natural echo - was excellent. Not only were the voices of the intended speakers excellently recorded but we also captured a quiet acknowledgment from the bride's mother seated beside the groom when he mentioned her. I doubt that would have been captured by a miniature lapel mic.

When the programme's edited I'll post a small clip of one of the speeches.

[Chris Harding]

Hi Philip

Following your lead I found a BM made by Crown in the USA on eBay so I will have something to play with too. I'm wondering how effective it will be on our usual lecterns which are around a surface area of 4 - 5 sq feet at the most but the speaker is fairly close most of the time. I currently just clip a lav onto the actual lectern or on a light stand off to the side. If one had a boundry on the actual lectern it would be great!!

Look forward to you posting a quick sample clip!!

Chris

[Philip Howells]

Chris, I'd try the Crown PZM (if that's what you're referring to) carefully before purchase. AFAIK, its unbalanced, very noisy and looks pretty unattractive - it's still used in police stations here I think (though it's a long time since I've been in a police station interview room - I used to be an official police visitor in case you think I'm revealing my low-life history).

As I recall the Crown PZMs are quite inexpensive and the ATs cost me £152 plus tax each.

[Chris Harding]

Hi Philip

In fact Radio Shack used to sell them for under $50 I believe. I was eyeing the AT ones. Nope, this one is purely to play with and get some ideas...then I will go for decent ones!!! Yes from the pics it looked unbalanced with just a single jack on a cable!!

Chris

[Nigel Barker]

Originally Posted by Chris Harding

In fact Radio Shack used to sell them for under $50 I believe.

I used to have a couple of those purchased over 20 years ago in a half price sale from a Tandy store (as Radio Shack was known in the UK). They were remarkably good quality & clean sound for the price, very robust & did not distort at high sound levels which was ideal as I used them for recording our rock band practising.