Want to build a Binaural mic head... thoughts...

[toomanyorgans]

Going to build one of these. My friend is donating to me the dummy head :-) Trying to decide what mics to use... anybody have thoughts suggestions experience? thinking maybe either a pair of octava (omni?) or maybe a couple of sony ecm mini condensers etc.... ???

[antti]

Check http://www.binaural.com/
Tchad Blake did some of his binaural stuff with a pair of ecm70s (if I remember right?). Please, keep us posted with your diy project. Good luck!

[PlugHead]

FWIW,

I made one with my DPA 4060's, and a haircutter's dummy model head (plastic)...

The only downside in making your own is it'll never truly be "binaural", as there has to be ear canals, and the mics to be positioned in there (I forget the pathology names - eustachian tube/etc., but you get the point!)

That said, it can be very useful - I've recorded a choir, and acoustic gtr, kit etc., with OK results, but usually SD mics are more noisy than LD's, and are better suited to "louder' subjects.

Best with it!

[billgaylord]

Some links that might be interesting to you:

You can get some amazing sound from these amazingly inexpensive microphone capsules (which are small enough to fit an ear canal opening), as explained on Siegfried Linkwitz's web site...

http://www.linkwitzlab.com/sys_test.htm

Stereo mic circuit using the Panasonic capsules...

http://www.linkwitzlab.com/images/graphics/microph2.gif

I have made my own binaural dummy head microphone out of wood and casts of my own ears (WARNING--DO NOT try to cast your own ear unless you really know how!! If you just pour casting material into your ear and let it set, you will destroy your eardrums trying to get it out!! Or wind up going to the hospital to get it removed!! To do it right you have to have a reliable way to provide air to the inside to relieve the vacuum. DO NOT TRY THIS AT HOME!!)

The size and shape of the head gives most of the effect, with pretty good horizontal spacial resolution and a sense of the sound being outside the head (when listening with headphones). A sphere about the width of a human head works amazingly well! If the outer ear parts are accurate anatomically speaking, they will add the virtical (azimuth) direction cues. Position in the "ear canals"--it turns out that putting them close to the openning tends to work best if you don't have a way to do "diffuse field equalization" of your dummy head's response.

The sound images above, to the sides, and behind will sound great! To the front it will still be amazing, but might sound a bit closer than you expect, and sounds to the front might be harder to locate if they aren't moving. It turns out sounds to the front are coupled to vision to a sizeable degree. People listening to a binaural recording, instantly could hear the frontal sound image much more distinctly once they got a look at a picture of the sound sources! Pretty amazing stuff. Most people can get the same affect if they imagine the sound sources.

I made the head with 1/2" birch veneer plywood cutouts layered and glued together. Each layer was cut on a bandsaw to a horizontal cross-section template. Pretty laborious, but it makes a pretty rugged dummy head and it's acoustic properties seem to be decent (no annoying stray resonances). The back can be removed for access to the circuit board and microphone capsules and I attached a tripod mount to the bottom.

You can hear some recordings made with this microphone on my experiments web site (binaural link at the bottom):

http://wjgaylord.brinkster.net/

Bill Gaylord

[Jim vanBergen]

I always loved what I got using the Crown SASS-P and SASS-B mics. I expect you can find some interesting info & application notes on the Crown website with a little surfing. While the PZMs sound good, the B&Ks sounded GREAT.