M/S-stereo setup

Discussion in 'rec.audio.pro' started by Ben Krämer, Aug 28, 2003.

  1. Ben Krämer

    Ben Krämer Guest

    Hello group,

    I make many M/S-stereo recordings of classical music with the
    Schoeps CMC64 as "M", and CMC68 as "S", but I want a bit more
    ambiance of the concert hall / church in my recordings.
    Can I simply change the MK4 (cardioid) for a MK2 (omni), or is
    that not more a 'real true' M/S-stereo setup when I make use
    of a omnidirectional pattern for a M/S setup?

    Thanks,
    Ben Krämer.
  2. Scott Dorsey

    Scott Dorsey Guest

    Ben Krämer <soundNO@SPAMhetnet.nl> wrote:
    >
    >I make many M/S-stereo recordings of classical music with the
    >Schoeps CMC64 as "M", and CMC68 as "S", but I want a bit more
    >ambiance of the concert hall / church in my recordings.
    >Can I simply change the MK4 (cardioid) for a MK2 (omni), or is
    >that not more a 'real true' M/S-stereo setup when I make use
    >of a omnidirectional pattern for a M/S setup?


    Try it and see. It's different and it's wider, and it's got a very
    different stereo image. You might like it.

    Schoeps also makes a wide cardioid capsule that is between the MK4 and
    MK2.
    --scott

    --
    "C'est un Nagra. C'est suisse, et tres, tres precis."
  3. "Ben Krämer" <soundNO@SPAMhetnet.nl> wrote in message ...
    > Hello group,
    >
    > I make many M/S-stereo recordings of classical music with the
    > Schoeps CMC64 as "M", and CMC68 as "S", but I want a bit more
    > ambiance of the concert hall / church in my recordings.
    > Can I simply change the MK4 (cardioid) for a MK2 (omni), or is
    > that not more a 'real true' M/S-stereo setup when I make use
    > of a omnidirectional pattern for a M/S setup?
    >
    > Thanks,
    > Ben Krämer.


    I find that mid side with an omni in the center works very well for
    situations where I'll put 3 omnis across the front of an ensemble, but I
    want a bit more imaging than 3 omnis can give...

    For example, with a concert band, I'll often use 3 omnis across the front.
    With a MS (omni in center) as the center of that setup, I find that I get a
    bit more precise image, especially with the front of the ensemble.

    You may also like putting a Fig-8 in the center. Gives ambience from the
    rear lobe, but a great image....

    --
    Benjamin Maas
    Fifth Circle Audio
    Los Angeles, CA
    http://www.fifthcircle.com
  4. It's still M-S.

    The omni mic does not have the forward-facing figure-8 component of the
    cardioid. Therefore, the image width will change. I'm not sure whether it will
    widen or narrow, but it will change.

    The amount of rear ambience picked up will increase.

    One other point... Why didn't you try this before asking? You learn much more
    from doing something than asking about it.


    Ben Krämer wrote...

    > I make many M/S-stereo recordings of classical music with the
    > Schoeps CMC64 as "M", and CMC68 as "S", but I want a bit
    > more ambiance of the concert hall / church in my recordings.
    > Can I simply change the MK4 (cardioid) for a MK2 (omni), or
    > is that not more a 'real true' M/S-stereo setup when I make use
    > of a omnidirectional pattern for a M/S setup?
  5. David Satz

    David Satz Guest

    Ben Krämer wrote:

    > Can I simply change the MK4 (cardioid) for a MK2 (omni), or is
    > that not more a 'real true' M/S-stereo setup when I make use
    > of a omnidirectional pattern for a M/S setup?


    Some folks do say that an "M" microphone should be cardioid, but that's
    their hang-up, not Lauridsen's (the inventor of the system); it's neither
    a technical nor a historical requirement. The "M" signal should just be
    a reasonable mono pickup by itself--and that might mean any pattern
    whatsoever. Heck, I've even recorded M/S with a shotgun "M" (Schoeps
    offers a nice mounting accessory for the MK 8 "S" in that application),
    and I've done even more M/S recording using an MK 41 capsule for "M".

    --I'm actually more concerned about your proposal to use an MK 2 in place
    of the MK 4. Have you ever recorded at the intended distance with an MK 2?
    It's very flat on axis, but only on axis. Off-axis (from where most sound
    energy arrives when you use omnis, except in close-up recording and/or very
    dry acoustics), it has a high-frequency rolloff--see its polar diagrams.
    For miking distances that are typical of M/S recording, the MK 2S or MK 2H
    capsules would generally be preferred, I think.

    Alternatively if you really want only "a bit" more ambience in your
    recordings, you might consider trying an MK 21 "wide cardioid" for the
    "M" microphone.
  6. Ty Ford

    Ty Ford Guest

    In Article <1062108221.347359@cache2>, "Ben Krmer" <soundNO@SPAMhetnet.nl>
    wrote:
    >Hello group,
    >
    >I make many M/S-stereo recordings of classical music with the
    >Schoeps CMC64 as "M", and CMC68 as "S", but I want a bit more
    >ambiance of the concert hall / church in my recordings.
    >Can I simply change the MK4 (cardioid) for a MK2 (omni), or is
    >that not more a 'real true' M/S-stereo setup when I make use
    >of a omnidirectional pattern for a M/S setup?
    >
    >Thanks,
    >Ben Krmer.


    Ben,

    Call or email Buzz Turner at Redding Audio in CT. He'll know.


    Regards,

    Ty Ford

    For Ty Ford V/O demos, audio services and equipment reviews,
    click on http://www.jagunet.com/~tford
  7. Rob Reedijk

    Rob Reedijk Guest

    Likewise the S doesn't have to be bi-directional. But most people can't
    get their heads around that.

    Rob R.

    David Satz <DSatz@msn.com> wrote:
    > Ben Krämer wrote:


    >> Can I simply change the MK4 (cardioid) for a MK2 (omni), or is
    >> that not more a 'real true' M/S-stereo setup when I make use
    >> of a omnidirectional pattern for a M/S setup?


    > Some folks do say that an "M" microphone should be cardioid, but that's
    > their hang-up, not Lauridsen's (the inventor of the system); it's neither
    > a technical nor a historical requirement. The "M" signal should just be
    > a reasonable mono pickup by itself--and that might mean any pattern
    > whatsoever. Heck, I've even recorded M/S with a shotgun "M" (Schoeps
    > offers a nice mounting accessory for the MK 8 "S" in that application),
    > and I've done even more M/S recording using an MK 41 capsule for "M".


    > --I'm actually more concerned about your proposal to use an MK 2 in place
    > of the MK 4. Have you ever recorded at the intended distance with an MK 2?
    > It's very flat on axis, but only on axis. Off-axis (from where most sound
    > energy arrives when you use omnis, except in close-up recording and/or very
    > dry acoustics), it has a high-frequency rolloff--see its polar diagrams.
    > For miking distances that are typical of M/S recording, the MK 2S or MK 2H
    > capsules would generally be preferred, I think.


    > Alternatively if you really want only "a bit" more ambience in your
    > recordings, you might consider trying an MK 21 "wide cardioid" for the
    > "M" microphone.
  8. With an omni you don't have the disadvantage of the low frequency
    drop-off of two pressuere gradient mics. I have recorded with a 4006
    and a MKH30. The additional tonal depth makes this system work really
    well for many recordings.

    rt60


    On Thu, 28 Aug 2003 18:25:05 -0700, "William Sommerwerck"
    <williams@nwlink.com> wrote:

    >It's still M-S.
    >
    >The omni mic does not have the forward-facing figure-8 component of the
    >cardioid. Therefore, the image width will change. I'm not sure whether it will
    >widen or narrow, but it will change.
    >
    >The amount of rear ambience picked up will increase.
    >
    >One other point... Why didn't you try this before asking? You learn much more
    >from doing something than asking about it.
    >
    >
    >Ben Krämer wrote...
    >
    >> I make many M/S-stereo recordings of classical music with the
    >> Schoeps CMC64 as "M", and CMC68 as "S", but I want a bit
    >> more ambiance of the concert hall / church in my recordings.
    >> Can I simply change the MK4 (cardioid) for a MK2 (omni), or
    >> is that not more a 'real true' M/S-stereo setup when I make use
    >> of a omnidirectional pattern for a M/S setup?
  9. David Satz

    David Satz Guest

    Rob Reedijk wrote:

    > Likewise the S doesn't have to be bi-directional. But most people can't
    > get their heads around that.


    Count me in with "most people" on that--what do you mean?
  10. Bob Cain

    Bob Cain Guest

    Rob Reedijk wrote:
    >
    > Likewise the S doesn't have to be bi-directional. But most people can't
    > get their heads around that.


    Please assist us in that.


    Bob
    --

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

    A. Einstein
  11. Rob Reedijk

    Rob Reedijk Guest

    David Satz <DSatz@msn.com> wrote:
    > Rob Reedijk wrote:


    >> Likewise the S doesn't have to be bi-directional. But most people can't
    >> get their heads around that.


    > Count me in with "most people" on that--what do you mean?


    Do it the same way you would with a figure 8 mic. Do it only with a point
    source, i.e. it won't work if you are actually recording a large source that
    is "spreading" around the mics. You are effectively using just the
    left or right side to represent your room sound to create an artificially
    stereo image. But conventional MS is also artificially stereo, to me.
    I believe that if you can make all of your stereo information disappear
    by hitting the mono button, you have an artificial stereo image.

    I know---you guys are going to roast me on this one. But before you do,
    please try it first.

    Can you tell I don't like MS?

    Rob R.
  12. Well, it HAS to be left-right symmetrical. And only omni and figure-8 are
    symmetrical. And omni ain't gonna produce stereo. Which leaves figure-8.

    ?????

    >> Likewise the S doesn't have to be bi-directional. But most people
    >> can't get their heads around that.


    > Count me in with "most people" on that -- what do you mean?
  13. Sugarite

    Sugarite Guest

    > Likewise the S doesn't have to be bi-directional. But most people can't
    > get their heads around that.


    You mean the unpredictable nature of the information at +90 and -90 degrees
    on the X and Z axes of an omni side mic colliding when matrixed to stereo?
    Sure, you can do that, but you don't need to get your head around it to hear
    that it's not a realistic result.

    Just stick with fig-8
  14. ScotFraser

    ScotFraser Guest

    << Can you tell I don't like MS? >>

    Ah, then you've discovered the real meaning of "MS"?

    Maybe Stereo.



    Scott Fraser
  15. David Satz

    David Satz Guest

    Rob Reedijk wrote:

    > Do it the same way you would with a figure 8 mic. Do it only with
    > a point source, i.e. it won't work if you are actually recording a
    > large source that is "spreading" around the mics. You are
    > effectively using just the left or right side to represent your
    > room sound to create an artificially stereo image.


    I gather that you'd take the two microphones' signals and perform the
    usual sum-and-difference matrixing on them. But that would yield the
    equivalent of an X/Y setup in which the two microphones had different
    directional patterns from each other and were aimed at different angles
    away from the center line.

    The proper technical term for the result which this produces is, I believe,
    "something really weird sounding." Agreed, it wouldn't work well with wide
    sound sources; the question is how well it would work with anything else.


    > But conventional MS is also artificially stereo, to me.
    > I believe that if you can make all of your stereo information disappear
    > by hitting the mono button, you have an artificial stereo image.


    You're more than entitled to your own perceptions and concepts of what
    sounds "artificial"--we each listen in our own ways. But you're saying in
    effect that any stereo which is mono-compatible sounds "artificial" to you.
    If so, then you apparently put a lot of subjective emphasis on arrival time
    differences between stereo channels, and you're probably unhappy with the
    results of all coincident (X/Y) stereo recording methods--no?

    If that's _not_ the case, then I suspect that you have some fundamental
    misunderstanding of what M/S is. It's really just a way to make an X/Y
    recording indirectly and in a way that allows some adjustment of your
    microphone parameters after the recording is already "in the can."

    In fact you can take any coincident (X/Y) recording and matrix it to M/S,
    then rematrix the result (with different settings) back to a different X/Y
    pickup from what you began with. That, in effect, is what a variable blend
    control on a hifi preamp does--especially the type (as in the Apt Holman
    preamps) which allows spreading the image by adding more "S" to the matrix.

    When I saw your posting about how a figure-8 "S" microphone isn't strictly
    needed, I thought you might be referring to this technique. Have you
    thought it through? It reveals a lot about what M/S really does.


    > Can you tell I don't like MS?


    I'm not 100% certain, frankly, that you correctly understand what M/S is
    or how it works, or that you've ever heard it used rather than someone's
    misimpression of what M/S is--but yes, it's clear that you're no fan.

    That's cool, but no one listens to M/S recordings in their M/S form except
    when checking for technical problems. M/S has no "sound" of its own apart
    from the "sound" of coincident (X/Y) recording--and that can be with any
    directional pattern of microphone (including some which aren't on the map,
    except in continuously-variable-pattern microphones).
  16. Rob Reedijk

    Rob Reedijk Guest

    David Satz <DSatz@msn.com> wrote:
    > Rob Reedijk wrote:
    >> Do it the same way you would with a figure 8 mic. Do it only with
    >> a point source, i.e. it won't work if you are actually recording a
    >> large source that is "spreading" around the mics. You are
    >> effectively using just the left or right side to represent your
    >> room sound to create an artificially stereo image.


    > I gather that you'd take the two microphones' signals and perform the
    > usual sum-and-difference matrixing on them.


    Yes.

    > But that would yield the
    > equivalent of an X/Y setup in which the two microphones had different
    > directional patterns from each other and were aimed at different angles
    > away from the center line.


    No. Firstly, I don't consider MS and X/Y to be equivalent other than as
    a mathematical concept. Secondly, your X/Y model is asymmetric, my
    MS model isn't in it's end result.

    > The proper technical term for the result which this produces is, I believe,
    > "something really weird sounding." Agreed, it wouldn't work well with wide
    > sound sources; the question is how well it would work with anything else.


    I agree. But is in any more weird than conventional MS?

    >> But conventional MS is also artificially stereo, to me.
    >> I believe that if you can make all of your stereo information disappear
    >> by hitting the mono button, you have an artificial stereo image.


    > You're more than entitled to your own perceptions and concepts of what
    > sounds "artificial"--we each listen in our own ways. But you're saying in
    > effect that any stereo which is mono-compatible sounds "artificial" to you


    Yes

    > If so, then you apparently put a lot of subjective emphasis on arrival time
    > differences between stereo channels,


    Yes, and also uneven frequency/polar reponses.

    and you're probably unhappy with the
    > results of all coincident (X/Y) stereo recording methods--no?


    Not super happy with it.

    > If that's _not_ the case, then I suspect that you have some fundamental
    > misunderstanding of what M/S is. It's really just a way to make an X/Y
    > recording indirectly and in a way that allows some adjustment of your
    > microphone parameters after the recording is already "in the can."


    > In fact you can take any coincident (X/Y) recording and matrix it to M/S,
    > then rematrix the result (with different settings) back to a different X/Y
    > pickup from what you began with. That, in effect, is what a variable blend
    > control on a hifi preamp does--especially the type (as in the Apt Holman
    > preamps) which allows spreading the image by adding more "S" to the matrix.


    > When I saw your posting about how a figure-8 "S" microphone isn't strictly
    > needed, I thought you might be referring to this technique. Have you
    > thought it through? It reveals a lot about what M/S really does.



    >> Can you tell I don't like MS?


    > I'm not 100% certain, frankly, that you correctly understand what M/S is
    > or how it works, or that you've ever heard it used rather than someone's
    > misimpression of what M/S is--but yes, it's clear that you're no fan.


    David, I have a clear understanding of MS. Like I said, it is based on
    theory that mostly is impratical. I will admit one thing to you though.
    For some reason I love soundfield mics. And those take MS theory to
    a greater level of sophistication.


    > That's cool, but no one listens to M/S recordings in their M/S form except
    > when checking for technical problems. M/S has no "sound" of its own apart
    > from the "sound" of coincident (X/Y) recording--and that can be with any
    > directional pattern of microphone (including some which aren't on the map,
    > except in continuously-variable-pattern microphones).


    Like I said before, I don't agree with this. They are not equivalent.

    Rob R.
  17. David Satz

    David Satz Guest

    Rob Reedijk wrote:

    > [ ... ] I don't consider MS and X/Y to be equivalent other than as
    > a mathematical concept.


    I'm not sure what that means. What I mean is this: Every possible M/S
    arrangement has an equivalent X/Y pair--though to get that equivalent,
    the "M" microphone may need to have a continuously variable pattern.

    The degree of exactness in the equivalence is pretty darn close if you're
    judging by ear. When folks say otherwise, I tend to suspect that they
    didn't use figure-8s with an accurate enough polar pattern or flat enough
    frequency response--because then things can indeed start to wander around
    in odd ways in the left-right stereo image.


    > David, I have a clear understanding of MS. Like I said, it is based on
    > theory that mostly is impratical.


    Can you be specific? Many people use it--what are they (we) missing?


    And I wrote:

    > M/S has no "sound" of its own apart from the "sound" of coincident (X/Y)
    > recording--and that can be with any directional pattern of microphone
    > (including some which aren't on the map, except in continuously-variable-
    > pattern microphones).


    To which you replied:

    > Like I said before, I don't agree with this. They are not equivalent.


    OK, that's a little like if I were to say, "But 2 + 2 doesn't equal 4 the
    way most people think" and left it at that. Maybe I meant something very
    specific in my own mind--but the reader has little chance to find out what
    that thought might be.

    So would you care to oblige us by spelling out why one _can't_ matrix M/S
    to X/Y and X/Y to M/S as people (including me) have been doing for decades?
    You don't have to, of course, but I would really like to know what you mean,
    and your statements have been so general that I'm not sure what your view is.

    --best regards
  18. > I'm not sure what that means. What I mean is this: Every possible M/S
    > arrangement has an equivalent X/Y pair--though to get that equivalent,
    > the "M" microphone may need to have a continuously variable pattern.


    So would the mics in the XY pair.

    Might I observe that the SoundField mic -- which is effectively an MS pickup in
    all three dimensions -- permits synthesizing a virtual pair of mics with _any_
    pattern and _any_ angular separation pointing in _any_ direction.
  19. Rob Reedijk

    Rob Reedijk Guest

    This is the way I have always conceptualised MS. Perhaps I am incorrect.
    The concept of adding and subtracting signals from capsules in one
    geometric orientation in order to arrive at the equivalent siganal
    of capsules in another orientation relies on your mics having
    even polar responses in volume and frequency response. (Not really
    volume, but you get my drift). To have such microphones requires that
    they (figure 8 and cardioid) have identical capsules in an identical
    position with regard to the mic bodies. This is probably only possible
    with multi-pattern mics. Multi-pattern mics tend to be large diaphragm
    things with uneven polar frequency responses. So unless B&K makes
    a small diaphragm side-address multi-pattern mic, I don't think this
    concept can be be pratically implemented.

    Alternatively, if you worked backwards, and took a pair of KM184s,
    set them in X/Y, matrixed them to MS and generated a "figure 8" response
    90 degrees to the intersecting angle of the mics, just how useful
    would it be? I have never tried this, but I imagine it would
    be a fairly weird response.

    Rob R.

    David Satz <DSatz@msn.com> wrote:
    > Rob Reedijk wrote:


    >> [ ... ] I don't consider MS and X/Y to be equivalent other than as
    >> a mathematical concept.


    > I'm not sure what that means. What I mean is this: Every possible M/S
    > arrangement has an equivalent X/Y pair--though to get that equivalent,
    > the "M" microphone may need to have a continuously variable pattern.


    > The degree of exactness in the equivalence is pretty darn close if you're
    > judging by ear. When folks say otherwise, I tend to suspect that they
    > didn't use figure-8s with an accurate enough polar pattern or flat enough
    > frequency response--because then things can indeed start to wander around
    > in odd ways in the left-right stereo image.



    >> David, I have a clear understanding of MS. Like I said, it is based on
    >> theory that mostly is impratical.


    > Can you be specific? Many people use it--what are they (we) missing?



    > And I wrote:


    >> M/S has no "sound" of its own apart from the "sound" of coincident (X/Y)
    >> recording--and that can be with any directional pattern of microphone
    >> (including some which aren't on the map, except in continuously-variable-
    >> pattern microphones).


    > To which you replied:


    >> Like I said before, I don't agree with this. They are not equivalent.


    > OK, that's a little like if I were to say, "But 2 + 2 doesn't equal 4 the
    > way most people think" and left it at that. Maybe I meant something very
    > specific in my own mind--but the reader has little chance to find out what
    > that thought might be.


    > So would you care to oblige us by spelling out why one _can't_ matrix M/S
    > to X/Y and X/Y to M/S as people (including me) have been doing for decades?
    > You don't have to, of course, but I would really like to know what you mean,
  20. David Satz

    David Satz Guest

    Sorry, there was an error in my last posting and because of the long delay
    before Google Groups posts new messages, I couldn't attach this correction
    until now.

    I had written:

    > Every possible M/S arrangement has an equivalent X/Y pair--though
    > to get that equivalent, the "M" microphone may need to have a
    > continuously variable pattern.


    What I meant was:

    Every possible M/S arrangement has an equivalent X/Y pair--though to get
    the exact equivalent in every case, the microphones in that X/Y pair would
    need continuously variable patterns (i.e. settings available "in between"
    the conventional, well-established patterns) and of course the angle
    between them needs to be adjustable, as it normally is.

    Similarly, every possible X/Y arrangement has an equivalent M/S arrangement,
    though to get the exact equivalent in every case, the "M" microphone would
    need continuously variable patterns as well, and the ratio of "M" to "S"
    signals going into the matrix needs to be adjustable--as it normally is.

    This is embarrassing because my point was to insist that the _other_ person
    be as clear as possible. No doubt this illustrates some important spiritual
    principle about the risk of going around challenging other folks ...

    (Bill Sommerwerck caught this error also; thanks.)

    --best regards

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