MS - I get it, but how does it work?

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Halion

Halion

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Ok, I know about the MS technique of recording, using a cardioride and a figure-8 mic, with a Y cable and, and with 1 channel 180 out-of-phase. Now what I don't get is how this can create a good stereo image. My logic goes like this:

3 channel, channel 1 and 2 are from the figure-8, channel 3 from the cardioride.
Channel 2 is 180 phase-reverse.
Would this not mean that channel 1 and 2 cancel each-other out completely (because they are exactly the same, except that they are exactly 180 degrees out-of-phase)? So figuring on from there, an MS recording should result in a mono mix.

Now ofcourse, the cardioride mic pics up alot of signal that is (almost) the same as either side of the figure-8, so that would mean......what....?

I don't understand what the phase of a signal has to do with it's placement/direction. Could someone point out what I figuring wrong here?
 
First of all, the two channels that have the figure 8 mic are 180 degrees out of polarity and are panned hard left and right and the cardiod mic is panned center. The amount of the two fig 8 channels that you bring up determines how "stereo" it will sound. The reason this technique is so popular is that WHEN COLLAPSED TO MONO this MS set up still basicly sounds the same as far as timber goes. The two fig 8 channels cancel each other out rather than doing some kind of comb filter thing which can result in a VERY strange sound.
Question; how are you placeing the fig 8 mic? You're not pointing one of the lobes at the source are you?
 
You have to set up the figure 8 mic to point left and right to the source. (that is the side part) You set up the cardiod mike just over (or under) the figure 8 so that the capsules are lined up with each other and pointing directly at the source.
The figure 8 is picking up the left and right info and very little of the center (mono). Just like if you take a stereo widener plugin and push it all the way to stereo. The cardioid is picking up the center (mono) info. The combination of the 2 will give you a coherent stereo image that will still sound good if you listen to it in mono.
 
Scroll down and read my second response on THIS thread. It should clear things up.


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I know how the mics should be placed. That I just don't get it how this can create a good stereo image. Both left and right are picked up by the same mic, and the with the 180 polarity change, what would change? Would each channel of the figure 8 only pick up sound from one side of the figure 8 mic?
 
Halion said:
I know how the mics should be placed. That I just don't get it how this can create a good stereo image. Both left and right are picked up by the same mic, and the with the 180 polarity change, what would change? Would each channel of the figure 8 only pick up sound from one side of the figure 8 mic?
Click to expand...

Read the link I posted. It is all in there.

It is the combination of the mics that makes it work. the mid mic is showing up on both sides, and because of the inverted polarity (it is not 180 degrees by the way. 180 degrees is to do with phase, and has NO bearing on polarity) of one of the sides, the mid mic cancels out different information on each side. Remember, the polarity of the back side of the figure 8 mic is inverted.

Read the thread I posted. It has pictures and everything to explain EXACTLY what you are asking. HERE it is again.


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"Cowards can never be moral."
M.K. Gandhi
 
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