Originally Posted by lowfreq33
For M/S you should have 2 of the same mic. You want the frequency response between the 2 to be the same. Stereo micing a mono source is kind of pointless.
I would respectfully, disagree with both of these points. Months back I took on "stereo" recording of mono sources as a way of sculptoring tone and dimension. I was referred to a multitude of books and the best in my humble opinion THE MICROPHONE BOOK, John Eargle, and THE NEW STEREO SOUNDBOOK, Ron Streicher & Alton Everest. I also picked up some matched condensor mics, some with multipattern and some without.
AEA, Wes Dooley makes a mic bar that will hold a pair of mics in various positions in including MS. This is really really nice because you can move the MS pair anyware you want it so the setup is a snap. The "S" mic needs to be a fig 8 and must be equal on the front and back. Some fig 8s have a different sound on the front and back. Ribbon or condensor will do. The "M" can actually be anything from fig 8, cardioid, to omni and will work with any kind of mic-- dynamic, condensor, or ribbon.
On the other hand to use XY, Blumlein technique, ORTF, etc requires matched mics. So that the frequency response of the right and left will be matched. With the MS technique the "S" mic provides the right and left information and is, of course frequency and directionally matched with itself perfectly (just out of phase front and back).
Refer to THE NEW STEREO SOUND BOOK chapter 7.14 for a great description of setting up and coding/decoding for MS technique which is beyond the scope of this thread.
PERSONAL OBSERVATIONS-- If a tracking space has a good ambient sound the MS technique provides "S" information that will give a mono source stereo dimension. The "S" mic is for the most part only recording the room and not the source per se because the source as at the null point of the fig 8. If the track ends up mono and not stereo the "S" ends up totally canceled out. If the tracking space doesn't have a good ambient sound I have found it ain't worth the trouble. However, with Wes Dooley's handy dandy bar I always have a MS setup ready to move into action. I think of the MS as an approach to get a virtual stereo print of a mono source in a space just like one would hear a mono source with two ears in a space. Further, if the "stereo" image ends up mono, rather than having phase issues the sides just cancel out.
This is a great technique to play with has pushed me to understand that stereo recording technique isn't just panning right or left.