[NewMusic] Core Sound ambisonic mics

[barry threw]

Fuck.  You're both right.  Apologies.

Yeah, the orders need more than the four standard channels...

Live and learn.  To the books.

At any rate, with the method I described you can do ambisonics  
without a sound-field mic, and with a standard mixer with busses.

Is sound-field to b-format a simple add subtract?

b

On Nov 7, 2007, at 11:24 AM, Matt J. Ingalls 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

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