>> FR-2LE doesn't have any provision for MS decoding.
>
> Please expand on this, in my mind MS can stand for a lot of things and
> being new to using microphones with recorders in place of hydrophones,
> you've lost me with this comment...
Glib answer: if you don't know what it is, you don't need it!
Real answer:
MS (M-S, M/S) is a one-point stereo microphone technique using a forward-fa=
cing cardioid mic (M for "mid") and a bidirectional (figure -8) facing left=
and right (S for "side").
The M and S signals can be passed through a simple circuit called a "matrix=
," the output of which is Left and Right stereo signals, very much like wha=
t you would get from an XY one-point stereo mic.
Four desirable features of this scheme: 1) the width of the stereo image ca=
n be adjusted during recording or in post by varying the balance of M & S; =
2) objects in the center of the sound field are on-axis to the M mic, rathe=
r than being 45 degrees off-axis to both mics as they are in XY, resulting =
in the best fidelity in the center of the image; 3) the system is inherentl=
y mono-compatible (just use M); 4) a single-point stereo mic is easier to h=
andle.
The disadvantage is that single-point stereo records no time differences, s=
o the recording will be less spacious on headphones.
MS is often done with two mics (like Sennheiser MKH 30 and MKH 40) piggybac=
ked inside one windscreen. There are also mics that are inherently MS. The =
latter often have a switch that allows decoding in the mic itself, so it pu=
ts out left and right signals. At least one mic, Sony's ECM-MS957, has MS e=
lements but only L-R output, so you wouldn't know it's MS unless you hold i=
t up to the light to see the capsules.
Some recordists record the M and S channels directly. This is only practica=
l where you have control of the audio processing chain; giving someone unfa=
miliar with MS an MS file will usually result in incorrect spatiality in th=
e product. BBC, for example, uses MS for field recordings and maintains MS =
through their chain. Most of us want to make files that someone can browse =
easily in 50 or a hundred years, so we usually decode the mic signals and r=
ecord conventional left and right stereo channels.
Pro recorders offer MS decoding to the recording tracks, and MS decoding to=
the headphones only (you would use one or the other, not both). That way y=
ou could lay down either MS or stereo tracks while listening to stereo.
-Dan
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