First mic the source in mono. This mic can be any polar pattern (though cardioid is most common) and feeds the "mid" channel which is sent equally to the L & R speakers.

Now add another mic with a figure 8 pattern, as close to the first as you can, angled so that the side null is facing the source and the sensitive lobes are pointing out to the sides. This mic feeds the "side" channel, which is added to the left channel and subtracted from the right (you can "subtract" a signal by inverting the polarity and adding it).

The level of the side mic relative to the mid mic will determine the stereo width.

"mid side" micing is a method of coincedent miking. coincedent meaning the two mic capsules are relatively close to each other. This is to ensure the least amount of cancellation for mono.

MS micing uses one capsule facing the object( M or Middle ), this one captures the main amount of sound and is generally replayed through both channels equally. the ( S or Side ) capsule is a fiqure 8 pattern and is perpendicular to the source, and basically picks-up the difference in response of the two sides ( IOW what will become the L and R channels ) when mixed the M track gets panned center, the S track gets duplicated into 2 tracks, one is mixed in with the polarity reversed and the other polarity normal, the two are then brought up in volume untill the desired amount of " stereo " is achieved. You can imagine then that this added signal would be adding and subtracting from the M signal thereby recreating the stereo field. Almost like a Encode/Decode process, first you have 3-dimensional sound (which has 3 dimensions to it right? Then is gets recorded and Encoded into 2 tracks/dimensions by the MS mics, then apon replay it is Decoded by combining the tracks in said procedure thereby creating a 3 dimensional sound again.

There are of course lots of other coincedent techniques as well, some of them inherently more accurate, however MS is particularly fun to play with, especially for some more exagerated effects.

Erik.

thanks

I have grabbed the text from both reply's and will read over and over till this sinks in. THanks for taking the time to reply. I got it I think and will try tomorrow ( was going to have sex) I'm a bit uncertain about the polarity .... actually what is that ? 8-)

From experience, if your preamp doesn't decode M/S for you get Voxengo's MSED, it will make life easier.
http://www.voxengo.com/product/msed/
Not that mixing the signal is hard, but why bother if you dont have to? And you can monitor your signal more accurately because whatever side you have your figure 8 setup on is going to sound disparately weak if you dont use the decoder for tracking.

From recent shopping around I know that Mackie's onyx pre's have an M/S decoder.
good luck.

Re: thanks

bluesdudeo wrote: ( was going to have sex) I'm a bit uncertain about the polarity ....

Well, the one with the penis is "male" or "positive".. oh, you mean audio polarity :lol:

If you are using a conventional mixer you invert the polarity using the "invert phase" button. This will invert the waveform so that the positive bits are now negative and vice versa, just as if you connected the red & black contacts the wrong way round on a speaker.

thanks again

I have a soundcraft ghost 24 track mute auto mixing board that has phase reverse but alas no room where I have my song writing lab and I only have a Behringer mini mixer which doesn't have it. Looks like I'm heading to the shop for a pre amp ? :( :cry:
Thanks again for your valuable time dude's.
Ps : merry christmas

Are you recording to computer or analog?

Typically you would only use 2 track to record the signal, one for M, and one for the S channel. Then in mixdown you'd convert it into 3 channells by duplicating the S signal into 2 (in analog you'd have to split the signal with a Y cable, in a DAW you can simply duplicate the track in the program) and then it is just a matter of reversing the polarity of only one S track ( most DAW's have this function available internally, in analog you'd have to reverse the signal wires on one output of the Y cable-assuming it is balanced).

what type of sources does ms micing generally work for?...could it be used to track amp and drums in a gtr/drum heavy mix?

jackson413 wrote: what type of sources does ms micing generally work for?...could it be used to track amp and drums in a gtr/drum heavy mix?

Sure, you can mic anything M/S if you want to. It makes most sense though if you want to recreate some "real" stereo image. Typical uses are for making "real" stereo recordings of, say a symphony orchestra, overheads for drums (looking down on the drums) and such things. If you are simply aiming to get two different sounds from the same instrument, say two mics on an acoustic guitar, it is not the go-to technique.

Gunnar