You are no doubt familiar with stereo miking (using two microphones panned hard left and hard right to create a stereo image), and have used it (or seen it used) to record drum kits, acoustic guitars, and so forth.
Now I present to you another form of stereo miking – Mid-side technique. It sounds like something from a Kung Fu movie, and it’s certainly a killer move.
*To record mid-side, you will need a mic with a cardioid pattern, and a second mic with a figure-of-eight pattern.
The idea is to get a focused and detailed sound from a cardioid mic pointed at the instrument, and a microphone with a figure-of-eight pattern picking up a stereo image. Usually used for acoustic guitar, the beauty of the mid-side technique is that the resulting recording gives you a great sound with an adjustable stereo width. Obviously, you will need to use your discretion when deciding how wide you want to spread the guitar.
Anyway, before we get bogged down in the detail, let me tell you the simplest way to achieve it.
As shown in the image above (and the title image), place the cardioid mic so that it is pointing directly at the source. The figure-of-eight mic should be placed at a 90 degree angle, with the front of the mic pointing left and the back of the mic pointing right. Setup two recording channels in your DAW – one for the cardioid mic and one for the figure-of-eight mic. That’s it!..for now. Record.
Now, here’s the tricky bit. The recording of the cardioid mic can be left alone. The recording from the figure-of-eight mic needs to be copied to another track, so that you have the same part on two tracks. Label one as ‘Side +’ and one as “Side -‘. Pan ‘Side +’ to the far left, and pan ‘Side -‘ to the far right. Now reverse the phase of ‘Side -‘. If you haven’t got a plugin or option to reverse the phase of a track in your DAW (or don’t know), there is a download link at the bottom of this post along with brief instructions. Pro Tools users have the Trim plugin, Studio One users have MixTool with both MS Transform and Phase Invert (Phase Invert should be used for this method), and for Logic users, I believe there is a phase reverse option for the Gain plugin.
Once you’ve successfully worked through these instructions, play back the recording with the mid (cardioid) mic at 0db and slowly bring up the two side (figure-of-eight) mic tracks. The side mic faders should always be equal. As the side mic faders climb, you’ll hear an enormous, glorious stereo spread of shimming guitar fade into your speakers. Or, you won’t – because you’ve done it wrong. Go back to the top and try again.