Freesound Forums
MS stereo = real stereo?
Started February 13th, 2007 · 3 replies · Latest reply by pcaeldries 17 years, 9 months ago
I never worked with MS stereo technique and I wonder, is it possible to record a car passing by so that you hear it coming from left and disappearing in the right?
Or do you have do do a lot of editing for that?
I'm asking because all the 'surround' sound is recorded to one channel.
Thats not completly true: It is also recorded to 2 channels. M and S (Mono and Side I guess). The M Signal is normaly a omnidirectional mic but is could also be a cardioid to the front. The S Signal comes from an orthogonal orientated figure of eight. This means that the one side has a inversed phase compared to the opposite side (left and right). You will get the one side by calucalting M - S and the other side by calculating M + S.
In reality this means that you have to add the S signal one times to M and for the other channel to add the inversed S signal to M. The result will be (L)eft and (R)ight.
The advantage is that you can adust the magnitude of M vs. S to and so influence the stereo wideness lateron without recording again.
MS only uses magnitude differences to create the stereo picture, it does not create time differences. This makes it mono compatible.
-Erdie
A good, not too technical discussion and comparison of different stereo techniques is availlable on the DPA Micropones site, Microphone University section:
Stations like the BBC enforce MS stereo on their recordists for documentary and HD TV I am told. Also I read that it is used a lot less in the US. A lot of good MS single point stereo mics are availlable. Dreaming of the ultimate set: MKH30/ MKH60 though I have positive experience with the Pearl MSH 10.
--Peter