Mid-Side Miking Technique

For some, mid-side miking may be a new-fangled technique shrouded in mystery, but it’s nearly as old as recording itself, and as it turns out, not a difficult technique at all. Invented in 1933 by Alan Blumlein, mid-side technique is a stereo miking technique that can be used on just about anything from guitars to pianos to strings to vocal groups.

The great thing about mid-side recording versus traditional stereo recording techniques such as x-y or spaced pairs is that mid-side recordings become fully mono compatible when summed. Not only that, mid-side offers control over the width of a recording that regular stereo miking cannot.

So, let’s get to the technique.

Mid-side miking – two stages

Stage 1 - Miking

Mid-side miking requires two microphones. In most scenarios this should be two microphones with very similar frequency response and character. Even better, use two of the same mics with switchable pickup pattern.

Mic one should be set to a cardioid or hypercardioid pattern – this is referred to as the “mid.” Mic two should be a figure 8 pattern – this is the “side”. Whether these are dynamics, condensers, or ribbons is up to you.

Place the mid so that it’s facing the center of the sound source. Place the side very close to the mid – usually underneath, just shy of touching. The side should be facing to the sides, so that the front and back of the figure 8 are left and right of the sound source, with the null facing toward the sound source. Usually, the front of the side mic is facing left, but this isn’t absolutely crucial.

Record each mic to its own channel.

Stage 2 – “Decoding”

What makes mid-side recording mid-side recording is what you do with the two tracks you’ve recorded with your mid and side mics.

After recording, copy the side mic track to another track, giving you two of the same exact track. Now flip the polarity 180 degrees on one of them (your choice which one). Now hard pan each of these two side mic tracks left and right, respectively.

What you end up with is three tracks – a mid track, which you can think of like the main source, and two side tracks, which you can think of as the ambient track. Now you can mix to taste. If you bring the mid up and the sides down, you’ll narrow the stereo image. If you emphasize the side tracks more, you’ll widen the image and make it more ambient. If you remove the mid entirely, though, you may notice the track ends up too empty. Also, removing the mid entirely means the track will entirely disappear when the recording is summed to mono.

This is why mono compatibility is perfect with mid-side technique. When the mix is summed, the side tracks cancel, leaving just the mid track. This can also help the mono version by removing ambience that may get muddy in a mono situation.

And that’s it! Mid-side miking isn’t so hard after all. You can also experiment with things like a different pattern on the mid mic – perhaps an omni or figure 8 pattern, or even see what happens with a unidirectional pickup. And although it’s not the norm, it can sometimes work to use disparate mics – for example maybe a brighter mic for the mid, to capture more detail while the sides capture ambience.

And finally, as always, the room you record in plays a huge part in the results you get, so pay attention to that aspect as you tweak your setup. Have fun with it, and don’t be afraid to try mid-side technique out in your next session!

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