You have a falsely encoded M/S audio file? Here’s how to deal with this:
Something practical for today: let’s assume you used a Mid/Side setup during one of your recordings but you accidentally mixed up the mid channel & the side channel and encoded it into left/right stereo already by using software or via hardware on location. The result will be an odd-sounding stereo image, having nearly now useful mid signal, jumping around 90° phase in your correlation meter with a lot of ambience and probably noise but no useful, clear and tight signal.
So, what led to this situation? The mid microphone was panned hard left and right and one side had a switched phase. The side signal however, originally a figure 8 microphone which catches up everything except what you are after, was panned to the center as a mono mic only. So, how can we reverse that to get the correct left/right stereo again?
First we’d like to separate the mid from the side signal. There are a bunch of MS capable plugins out there that can do that. The most easiest to use I found is the „bx_solo“ from Brainworx. We will do it with that one, you can download it here for Mac, PC and Venue (AAX, AS, AU, RTAS, TDM, VST):http://www.plugin-alliance.com/en/plugins/detail/bx_solo.html
Open a session in your host sequencer, place the false stereo image on one track and copy it to two new stereo tracks. On track 1 you might want to have the mid signal so simply turn on the Brainworx’ „S Solo“ button and pan both sides to mono. That is that, rock steady mid signal finished.
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To get the old mid signal resulting from setting the figure 8 microphone to the sides, which is where it belongs to, hit „M solo“ on track 2 and track 3. Insert a plug-in which can inverse the phase on track 3 and pan track 2 hard left and track 3 hard right.
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Finally, push or lower tracks 2 and 3 as suiting to widen or narrowing down the stereo image. That’s it with our little fire extinguisher for accidents… Hope that helps somebody.
