This post may not appeal to 90% of our site visitors, but for the few who care... If you record your own samples or sound FX, or do field recording, and arent familiar with the mid-side technique, prepare to have your mind blown. To the uninitiated, it seems like pure audio sorcery!
Imagine recording Center, Right AND Left, on just 2 tracks. now, imagine in POST, having full control over the ratio in the mix. The MS technique isn't new, but unless you're an audio nerd, it may have slipper under your radar, until now.
If you're like me, you love recording sounds, and there's often a mental tug-of-war over when to record in mono, or stereo. Both have their place, and regardless of what you're recording, there is always a physical space that it's being recorded in. That space has it's own characteristic, and dimension.
If you're holding a block of wood and striking it with a drum stick, all of the objects or walls in the room to the Right of your block of wood (or the Left of your microphone(s)), is likely going to reflect sound differently that the objects or walls on the opposite side. This is true even when we try to capture sounds in a very controlled environment, like a booth for instance, but more prevalent (and satisfying) in a real-world physical space. Stereo is of course the usually the most satisfying way to capture ambience around us... But what if you want the best of both worlds? The front and center strike of your wood block (or other sounds), and the dimension of that real-world physical space our ears are used to hearing... The answer is mid-side stereo.
What You Need
1 Figure 8 capsule mic, 1 Cardioid or Hyper Cardioid Pattern Mic, and a two track recorder (minimum 2trk). You can also experiment.. Some use an omni in place of a figure 8 capsule, or my favorite- a shotgun in place of a standard Cardioid.
In A Nutshell
Your mics are positioned so that your cardioid pattern mic (feeding recording channel 1 or L) is capturing the mono signal straight-on, and your Figure 8 pattern capsule (feeding recording channel 2 or R) is at a 90 degree angle, capturing everything to the Right and Left of your cardioid mic.
Decoding MS Stereo
Here's where the magic comes in. After you've recorded your source (in my example, a block of wood), with the signal from each mic to it's own track, you'll need to "decode" the recording to hear the actual stereo image. Load your best take(s) into your favorite DAW. Depending on what you use, there may already be an MS decoder built in. I'll assume there is NOT... But I WILL assume you're using a DAW. Next, you'll split the track recorded with Figure 8 capsule into two separate channels (One panned hard L and the other hard R), and reversing the phase on ONE of the channels (either one)! The result is a stereo view of exactly what your figure 8 capsule captured at both sides, but in stereo! Now you have 3 distinct tracks, 1 Center mono track from your cardioid mic, and 2 stereo tracks (L&R) from your figure 8 mic. They can be mixed together to gain the exact level of "room' vs direct source.
The best part is, you're never stuck with your results. You're free to revisit the same tracks and mix the direct signal with the stereo room to get the perfect balance.
There's plenty of articles online about MS recording, here's a few of the top search results:
Read a few & jump in!
I found the best way to wrap your brain around it was simply trying it, and hearing the results. The technique can be applied to all kinds of sounds, and is popular for recording acoustic guitar. For my purposes though- capturing drum samples, single instruments, vox & sound fx... it's pure magic.
The best of both worlds, in two tracks!
Here's a video from youtube that also gives a good audio example...