Robert Bigelow’s Tips on Mid-Side Mic Recording robert bigelowContinuing our series of Livestream sessions at NAB 2014, we return to Robert C. Bigelow for a new discussion on mid-side microphone recording. While hardly a new technique, many engineers shun mid-side because they don’t know how to properly execute this technique. Luckily for us, veteran sound mixer/editor Robert Bigelow does, and he was on hand to show attendees how it’s done. Mid-side microphone recording is used primarily for capturing ambient sounds and live music. It permits a wide array of stereo field sizes, much wider than with a single stereo microphone. Mid-side lets the engineer make the stereo field as wide or as narrow as desired. Here’s how it works. Position The first mic is your “mid” microphone, which should be set up to face the source you are trying to capture. The second “side” microphone is a figure-8 mic that will capture ambient noise and sounds in the room. Advantages audio-technica at4050The mid-side microphone is perfect for film because you can move the focal point based on the framing of the shot. If the shot is wide you can spread the audio track out to match the wide framing, and if the shot is pushed in tight on a solo musician or speaker, you can fold the track in. It’s extremely advantageous for interviews as well because the mid microphone captures the words of the interview accurately while the side figure-8 microphone captures the ambience. You can then balance those levels against each other in post-production for a true-to-life sound. Audio-Technica mid-side microphones, like the AT4050ST, offer well-configured mid and side elements within a single, durable housing. These mics can never slip off axis, and therefore never have phase issues. Use Recording occurs in two discrete channels. Don’t think of these as two separate focal mics. Set your mid levels first, and then match your side channel exactly. If they’re not leveled identically, decoding will be a technical annoyance. The figure-8 mic will pick up both the left and right sides. In decoding, you will spread the left ambience and right ambience apart, widening and detailing the stereo image. The mid microphone will always have a stronger waveform, so if you forget which channel is which in post-production, the larger waveform can help you reference the mid element. Once you’ve identified mid and side, duplicate your side track and invert it. Most recording programs will have the “invert” or “phase” option. Throw the copied track out of phase. Finally, combine your tracks to make a stereo track. Pressing play at this point will play the mono mid track, and as you bring up the side track you will hear the stereo image widen. Bringing the side levels back down will fold the recording back to mono. Play with these levels to find the right stereo sound. With the mid-side technique mastered, you’re ready to tackle any live recording, be it documentary, interview, or live music. Manipulate the levels until you have the stereo image your shot or musician calls for, and produce the ideal sound for any video. Try an Audio-Technica stereo condenser microphone to keep the mid-side arrangement in a single housing. Stay tuned for more tips from friends of Audio-Technica.