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martin griffith
 
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Default MS mic theory, dumb question (maybe)

Just pondering on getting a new/ebayed mic(s) for my video camera,
XL1s, and I was think of MS principles in general.

Take a standard MS setup, fig8 pointing sideways, and a cardiod
pointing forward.
If I put a second cardiod pointing backwards,using the same fig8 as
the front cardiod do I get good old fashioned Quad, but I know most of
the time I would just get ambience.

Just thinking aloud...

martin

"Wales is a big welsh-shaped rain collection device"
  #2   Report Post  
Oleg Kaizerman
 
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why?

--
Oleg Kaizerman (gebe) Hollyland

"martin griffith" wrote in message
...
Just pondering on getting a new/ebayed mic(s) for my video camera,
XL1s, and I was think of MS principles in general.

Take a standard MS setup, fig8 pointing sideways, and a cardiod
pointing forward.
If I put a second cardiod pointing backwards,using the same fig8 as
the front cardiod do I get good old fashioned Quad, but I know most of
the time I would just get ambience.

Just thinking aloud...

martin

"Wales is a big welsh-shaped rain collection device"



  #3   Report Post  
Paul Thomas
 
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martin griffith wrote:
Just pondering on getting a new/ebayed mic(s) for my video camera,
XL1s, and I was think of MS principles in general.

Take a standard MS setup, fig8 pointing sideways, and a cardiod
pointing forward.
If I put a second cardiod pointing backwards,using the same fig8 as
the front cardiod do I get good old fashioned Quad, but I know most

of
the time I would just get ambience.

Just thinking aloud...

martin

"Wales is a big welsh-shaped rain collection device"


I think you're better of just using two figure-8 mic's so there's
really only two diaphragms involved. No matter how close you get the
two cardiods to each other there will likely be some issues due to the
distance between them.

  #4   Report Post  
 
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I just recorded a concert that way using CCM Schoeps (front and rear
MS) and works very well.

But, do you intend to use the mics attached to the camera?

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been a sound recordist for 20 years + still mostly mono... mid-side raw
would be possible to the cam, but I think you are limited to two inputs
on the cannon, so no quad in the field. Mid Side must be matrixed so
that one side of the fig8 is in phase with the mid and the other side
out. Changing the phase relationship widens or narrows the stereo
sound-field and the mid can always be used as mono. This is the
advantage of MS...it can always be used mono with no side to avoid
stereo phasing anomalies in mono broadcast situations. Heck Martin just
share the wealth and hire a sound recordist but remember "For every
expert there is an equal but opposite expert" Why not? "the only
dumb questions are the ones that never get asked" Good Luck, Jeff



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oops, I think you will need the matrix between the mics and the
camera. most field mixers fp33 sd442, pscm4a+ and others have this
function also Shure makes a mic (VP-88) with the matrix built in. If
I have caused any confusion I apologise Jeff

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Paul, come on! You suggest using two figure 8s because of issues
regarding cardiods. if you don't know what MS stereo recording is,
please remain in the grip department .

  #12   Report Post  
Jay Rose CAS
 
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...This is the
advantage of MS...it can always be used mono with no side to avoid
stereo phasing anomalies in mono broadcast situations....


If it's recorded right, the S automatically disappears when you sum to
mono. A form of m/s encoding is also the basis of stereo analog radio and
tv, with the m signal transmitted on the main carrier, and the s
transmitted on a higher frequency subcarrier that mono sets ignore.

--
Correct address is spell out the letter j, AT dplaydahtcom
Clio- and Emmy-winning sound design
Learn audio for video at www.dplay.com
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David Morgan \(MAMS\)
 
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"Jay Rose CAS" wrote in message ...

...This is the
advantage of MS...it can always be used mono with no side to avoid
stereo phasing anomalies in mono broadcast situations....


If it's recorded right, the S automatically disappears when you sum to
mono. A form of m/s encoding is also the basis of stereo analog radio and
tv, with the m signal transmitted on the main carrier, and the s
transmitted on a higher frequency subcarrier that mono sets ignore.

--
Correct address is spell out the letter j, AT dplaydahtcom
Clio- and Emmy-winning sound design
Learn audio for video at www.dplay.com



Nice to see you here in r.a.p. again, Jay.... even if by crosspost.


--
David Morgan (MAMS)
http://www.m-a-m-s.com
Morgan Audio Media Service
Dallas, Texas (214) 662-9901
_______________________________________
http://www.artisan-recordingstudio.com



  #15   Report Post  
Allen Sklar
 
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Hello Martin
A while back, someone posted a few GREAT links for information
about M-S recording.....
As soon as I can find them, I will post the links....

Allen Sklar
Audio By Allen LLC
Tempe Az


martin griffith wrote:
Just pondering on getting a new/ebayed mic(s) for my video camera,
XL1s, and I was think of MS principles in general.





  #16   Report Post  
Bob Cain
 
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SSJVCmag wrote:
On 4/11/05 11:08 AM, in article ,
"martin griffith" wrote:


Just pondering on getting a new/ebayed mic(s) for my video camera,
XL1s, and I was think of MS principles in general.

Take a standard MS setup, fig8 pointing sideways, and a cardiod
pointing forward.
If I put a second cardiod pointing backwards,using the same fig8 as
the front cardiod do I get good old fashioned Quad, but I know most of
the time I would just get ambience.

Just thinking aloud...



Doesn;t sound like you understand how MS works.
You either get

A) the badly-approximated equivalent of an MS using an OMNI instead of a
card


By summing the front and rear card to a single M signal.

I dunno about it being badly-approximated, however. In what
way do you mean?

which decodes nicely as hearing the WHOLE ROOM in stereo and images
very well.


If you like the sound of two first order mics, (sub to
hyper)cardiods, pointing due port and due starbord.


B) the badly-approximated equivalent of Blumlien-MS where you have crossed
fig-8's with one pointing forward. This decodes exactly like normal XY-8's
pointed 45 L and 45 R with all of the critical 'don;t place things here'
zones that that rig mandates.


By subtracting the rear card from the front one to a single
M signal.

Actually, I favor this approach for the S signal when making
a mic from capsules because it is easier to find three well
matched cards than it is to find a card and a fig 8 that are
well matched. When each mic is big and bulky with screens
around them or metal tubes behind them, getting low
diffraction spatial coincidence is not very likely.


Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein
  #17   Report Post  
damifino
 
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Thanks for the gozinda (input)..... Is anyone recording other than
ambience using Mid Side. Thanks j

  #18   Report Post  
 
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HEHE seems like Wales is a welsh shaped smart ass collecton device
filtered white/pink noise.... gee what kind of filter white or pink....
you post guys crack me up

  #19   Report Post  
 
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A second cardioid facing backward on an MS array will make the mid
signal esentially omnidirectional. If you reverse the polarity on the
second cardioid, you are creating a de facto figure 8, approaching "MS
Blumlein"

In no case are you creating a quad signal, but if you play a blumlein
pair back through a dolby pro logic system with rear speakers, you will
get some really interesting results.

bottom line-- any microphone may be used for the "MID" of an MS array.
better one microphone than two.

Richard Kuschel

  #21   Report Post  
martin griffith
 
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On 13 Apr 2005 10:20:02 -0400, in rec.audio.pro
(Scott Dorsey) wrote:

wrote:
A second cardioid facing backward on an MS array will make the mid
signal esentially omnidirectional. If you reverse the polarity on the
second cardioid, you are creating a de facto figure 8, approaching "MS
Blumlein"

In no case are you creating a quad signal, but if you play a blumlein
pair back through a dolby pro logic system with rear speakers, you will
get some really interesting results.


No, no, the notion is to put a second cardioid facing backwards, and
record it to a discrete third channel. This _does_ give you a channel
of rear information to work with, albeit one without directional cues
other than thase from the S mike.
--scott

Hmm, Since i started the OP,.
Continuing what Scot has said
The whole system is symmetrical, there is no difference between the
front and rear cardiod, either can be front OR back. So the sideways
fig8 is common to both front and rear systems.
This implies that with 3 mics you can have 4 channels with suitable a
matrix.
Going back to Scott
This _does_ give you a channel
of rear information to work with, albeit one without directional cue


Well if you de-matrix (?) the rear cardiod with the (normally front) S
signal, does this not mean you will have directional clues, for rear
speakers? Since the S signal dont know anything about rear or front
signals.

confused, ... almost



martin

"Wales is a big welsh-shaped rain collection device"
  #22   Report Post  
SSJVCmag
 
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On 4/13/05 5:50 PM, in article ,
"martin griffith" wrote:

On 13 Apr 2005 10:20:02 -0400, in rec.audio.pro

(Scott Dorsey) wrote:

wrote:
A second cardioid facing backward on an MS array will make the mid
signal esentially omnidirectional. If you reverse the polarity on the
second cardioid, you are creating a de facto figure 8, approaching "MS
Blumlein"

In no case are you creating a quad signal, but if you play a blumlein
pair back through a dolby pro logic system with rear speakers, you will
get some really interesting results.


No, no, the notion is to put a second cardioid facing backwards, and
record it to a discrete third channel. This _does_ give you a channel
of rear information to work with, albeit one without directional cues
other than thase from the S mike.
--scott

Hmm, Since i started the OP,.
Continuing what Scot has said
The whole system is symmetrical, there is no difference between the
front and rear cardiod, either can be front OR back. So the sideways
fig8 is common to both front and rear systems.
This implies that with 3 mics you can have 4 channels with suitable a
matrix.
Going back to Scott
This _does_ give you a channel
of rear information to work with, albeit one without directional cue


Well if you de-matrix (?) the rear cardiod with the (normally front) S
signal,


The S is just SIDE, not 'front' or 'back'

does this not mean you will have directional clues, for rear
speakers? Since the S signal dont know anything about rear or front
signals.

confused, ... Almost


Not so much! the back-facing card decoded with the Side would inded be a
back-facing stereo thing.

Interestingly what you;ve invented here is pretty much the
CALREC/SOUNDFIELDn capsule array. 4 diaphragms that can be dematrixed in a
number of ways to get all this.


  #23   Report Post  
Bob Cain
 
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SSJVCmag wrote:

Interestingly what you;ve invented here is pretty much the
CALREC/SOUNDFIELDn capsule array. 4 diaphragms that can be dematrixed in a
number of ways to get all this.


The Soundfield mic has four capsules, each on the face of a
tetrahedron. It is a 3-D device, not a 2-D device and from
the signals you can decode logical mics with any 1st order
pattern pointing in any direction. That's with ideal
capsules, of course. Real world capsules impose a whole lot
of inaccuracy in that.


Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein
  #24   Report Post  
Scott Dorsey
 
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martin griffith wrote:
Continuing what Scot has said
The whole system is symmetrical, there is no difference between the
front and rear cardiod, either can be front OR back. So the sideways
fig8 is common to both front and rear systems.
This implies that with 3 mics you can have 4 channels with suitable a
matrix.
Going back to Scott
This _does_ give you a channel
of rear information to work with, albeit one without directional cue


Well if you de-matrix (?) the rear cardiod with the (normally front) S
signal, does this not mean you will have directional clues, for rear
speakers? Since the S signal dont know anything about rear or front
signals.


If you de-matrix the rear cardioid with the side signal, anything to
the side of the stereo image, even if it's up front, will appear in
the rear channels. I don't like that. I'd rather have too little
rear pickup than too much.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."
  #25   Report Post  
Kurt Albershardt
 
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damifino wrote:
Is anyone recording other than ambience using Mid Side.


Yes. Can work on almost all sections, pianos, drum kits, acoustic
guitars, standup basses, assorted squeezeboxen, and of course as a main
pair on acoustic ensembles.



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