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Binaural Microphone


Diego Sanchez
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I'm going soon to Qatar to film a documentary that is pretty much Qatar in the eyes of a blind man. Yes i did write it correctly so you can imagine how important sound is and specially atmospheres.

So i wanted to buy a binaural mic that i could record some nice atoms with during shoot and after.

As mostly is going to be during the shoot, i wanted something small and unobtrusive as i am by myself.

Surround mic was a nice idea, but neither budget or space allow for it, and the only small one (Sanken WMS-5) is not available to rent in the UK.

Looking at good small binaural microphones, i realised most are just two good omnis tweaked and positioned to work as 1 stereo/binaural mic.

I realised, i have a few good omnis in my kit, the cos11 lavs. So i decided to create a mount for them to use them as binaural.

I used a pvc tube and foam inserts similar to hush-lavs but thicker:

post-3119-0-72235600-1346853491.jpgpost-3119-0-67308600-1346853451.jpg

The 'ears' i made out of Sugru to have a bit of wind cover (although the sanken wind cover fits inside too), for a bit of back rejection and to make it look cool:

post-3119-0-64503800-1346853510.jpg

I use 2 Ambien EMP5S to connect directly to 48v phantom, but i can also use 2 wireless if needed:

post-3119-0-99212500-1346853530.jpg

The size of the tube is so it can fit on my bag for on the shoot ambience, but has a mounting screw for a stand:

post-3119-0-79576800-1346853559.jpgpost-3119-0-09193500-1346853580.jpg

I was going to upload some test recordings but i figured i'll wait and upload the actual ones i'll be recording on the documentary.

Opinions welcome

Thanks for reading

Diego

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I have some of the soundman microphones. They are designed to be worn in the ears and do their response is very similar to your own hearing. Send me a message if you want to borrow (or buy) them, as they have sat in my cupboard for quite a few years now.

They do give a very good sense of space when listened back to on headphones, though I found sudden head turns to be very disconcerting, as the sound field shifts when you aren't.

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http://soundlandscapes.wordpress.com | Rich, search this blog. I think he have good results with SoundMan Binaural microphones. And that's why recommend to Diego this brand. I don't have personnal experience with this microphones but I believe it's quality product.

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diego, great!

can you make those ears a little bigger and more like ears? I dont know if this will make a difference. Also, i feel a good bit of damping is needed on the tube itself. it may make resonances that are unnatural and unwanted. thinking in terms of how a human head damps out stuff... just a thought, i am no expert on this...

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diego, great!

can you make those ears a little bigger and more like ears? I dont know if this will make a difference. Also, i feel a good bit of damping is needed on the tube itself. it may make resonances that are unnatural and unwanted. thinking in terms of how a human head damps out stuff... just a thought, i am no expert on this...

Thanks Vin, i did wanted to make the ears bigger, but then i thought they might get on the way. And as for making them more realistic, well... i tried but i'm not very crafty. Besides in the human ear is really the inside and a bit of the colchea that change the sound. The rest is just to put earrings ;)

As for the dampening, i did thought on that, that is why the foam that holds the mics, that is like a hush-lav, runs from each end almost to the middle. You can see it in the 4th picture.

When i tried it I did not hear any resonance or weird tube distortion.

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  • 1 month later...

So have been 3 weeks on this job and have recorded some nice stuff with this mic. Here is my favourite

http://www.soundiego.co.uk/BinaTrio.wav

We recorded on a sound studio, so i used a few more mics, but i placed this mic just below the keys of the keyboard to capture the sound as the main character (the blind keyboard player) heard the music.

Hope you enjoy it.

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IMMO the right distance between microphones must be 17cm (the distance between ears), also, I guess you need a baffle for better stereo separation (specially for the upper frequencies). A head is the right thing, but a baffle like a jeclin disk (Half in your case) will be more than enough.

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A large part of the concept of binaural recording is dealing with reflections off all parts of the human head. Not only do you need full ears with pinnae, you need the nose in front. A dummy head would work wonders for your setup.

Also, hard to tell from the photos, how far apart did you put the two mikes?

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A dummy head or HRTF is certainly applicable, but not necessary in this context.

Also look up "Jecklin discs". The disc substitutes for the head between the spaced omnis (the ears), and is only sufficient to attenuate high freqs from crossing over.

HRTFs lump in the whole response of the microphone and dummy head, and then assume the response of the playback mechanism (usually headphones).

In practice, spaced omnis sound good, spaced omnis with a Jecklin disk (even home-made) sound better, and if you're thinking about dummy heads and HRTFs, you're a post-grad working on a dissertation...

The model ears will certainly help with giving the recording less rear sensitivity, but make it more difficult to post process the recording to extract (or attenuate) sounds that aren't out in front. For Atmos recordings, I'd say you're 90% of the way there already.

Tom (wishes he had the time and money to go back and study acoustics at post-grad level)

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I did think about a dummy head or a Jecklin disc, but unfortunately i had to use this mic while it was filmed, so a bit of hiding was necessary. The distance between the mics was 25 cm +or-.

If you can, try to cut the bar to 17cm (According to the photo you can do it), the bag will act as a baffle. ^_^

In other hand

http://www.soundman.de

http://core-sound.com/default.php

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I did a lot of this kind of recording in situations where obvious recording equipment was not allowed (religious services, political situations, restricted areas etc). I couldn't use any sort of handheld mic (or dummy head certainly)--the best thing I came up with was some lav mics mounted inside the earpads of some lightweight cheap headphones (with the drivers removed). I would rest the headphones on either side of my collar, with the "headphone" cable going down into a bag where the recorder was (which I'd start before I entered the room). While not correct "binaural" at all it sounded pretty good and we used a lot of it in a series we did for the Disney Channel (which won an Emmy). This might be tougher now that the normal music headphones are buds, but I think it might still be possible to make something that would pass unnoticed.

philp

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