[NewMusic] Core Sound ambisonic mics

[David Slusser]

I've messed a little bit with do-it-yourself m/s and with finely
calibrated mic/encoder packages.  Either, when done without a
decoder, are typically brought out on three faders where the
mixer spreads to their own taste.  Endusers don't seem to be
interested in "photographic" reproduction at that point, so DIY
can be fine.  You guys probably have all sorts of formulae for
this.  (I once got results with an RCA 44 ribbon and a shotgun.)

What's interesting about the Core array is that it's a parallel to
visual "motion capture" in digital animation, where the director
can re-plot all the camera work after a performance has been
recorded by its array of cameras.  The mic system seems like a
great tool, ideal for one time events (no take 2), and will
probably get us to the holo-deck a lot sooner.


On Nov 7, 2007, at 11:35 AM, cliff caruthers wrote:

> Also, one bidirectional and omni does not equal m/s, even kind of.
> For the imaging to work properly, has to be a cardioid with with a
> figure eight...
> -Cliff
>
>
> On 11/7/07, Matt J. Ingalls <ingalls at mills.edu> wrote:
>>
>> barry:
>> tom is right. soundfield mic is 4 cartiods in a tetrahedron (a- 
>> format),
>> which is full 3-D. output is usually transcoded (simple add&subtract)
>> to b-format which is
>> the omni+3 bi-directional (WXYZ) you are talking about.
>> and i believe this is "1st order" whereas "2nd+ order" is more  
>> channels
>> added to that..
>>
>> -m
>>
>> On Wed, 7 Nov 2007, barry threw wrote:
>>
>>> You actually need 3 *bi-directional* mics and one omni, and they are
>>> as close to coincident as possible (without fancy delay processing).
>>> But, that is only for 3rd order (preserving height information).
>>>
>>> For second order you can need 2 bi and one omni; that will give you
>>> accurate recording of a 2D sound field.
>>>
>>> For stereo, all you need is one bi and one omni.  But thats M/S  
>>> (kind
>>> of) and we all knew about it.
>>>
>>> b
>>>
>>> On Nov 7, 2007, at 9:45 AM, Tom Duff wrote:
>>>
>>>>
>>>> Just noticed this for recording weenies:
>>>>
>>>> http://www.core-sound.com/TetraMic/1.php
>>>>
>>>> It's an ambisonic transducer (tetrahedral coincident array of  
>>>> cardioid
>>>> mics) for under $1000.  Looks great.  Len Moskowitz (Core Sound)
>>>> usually
>>>> makes first-rate stuff for the price.
>>>>
>>>> Ambisonic recording is extremely cool.  By using 4 directional mics
>>>> evenly
>>>> spaced in 3-D, you can, by appropriate mixing, simulate arbitrary
>>>> coincident microphone arrays.  If you use a 4-channel recorder, you
>>>> can
>>>> even change miking decisions after the fact.
>>>>
>>>> --
>>>> Tom Duff.  Hwanon ferigeath ge faette scyldas?
>>>> _______________________________________________
>>>> Bay Area New Music Discussion Group
>>>> NewMusic at music.mills.edu
>>>> http://music.mills.edu/mailman/listinfo/newmusic
>>>
>>> Barry Threw
>>> Media Art and Technology
>>>
>>>
>>> San Francisco, CA     Work: 857-544-3967
>>> Email: bthrew at gmail.com
>>> IM: captogreadmore (AIM)
>>> http:/www.barrythrew.com
>>>
>>>
>>>
>>> _______________________________________________
>>> Bay Area New Music Discussion Group
>>> NewMusic at music.mills.edu
>>> http://music.mills.edu/mailman/listinfo/newmusic
>>>
>> _______________________________________________
>> Bay Area New Music Discussion Group
>> NewMusic at music.mills.edu
>> http://music.mills.edu/mailman/listinfo/newmusic
>>
> _______________________________________________
> Bay Area New Music Discussion Group
> NewMusic at music.mills.edu
> http://music.mills.edu/mailman/listinfo/newmusic