Recently, a reader asked whether Audition supports mid-side (MS) audio. This got me doing some research.
Sound Devices describes M/S (mid-side) audio as a “popular stereo microphone technique because of its good spatial imaging, mono compatibility, surround-sound compatibility, and ability to adjust the stereo field in post production. MS stereo is a two microphone capsule technique using a primary microphone as the mid-signal and a bi-directional microphone for the side-signal. A stereo signal is generated combining these two microphones, with different polar responses, in an electrical matrix. Whether decoded during recording or in post production, the amount of stereo spread can be adjusted, a great benefit of M/S stereo over other stereo microphone techniques.” (Link)
I next reached out to Adobe to learn if Audition supported it.
Durin Gleaves, Audio Product Manager at Adobe for Premiere and Audition, told me:
Audition supports M/S encoded recordings and can work in that space. We have some effects, like Channel Mixer, which have M/S conversion presets, and Matt created several Rack Presets to support those workflows as well. Additionally, we’ll support any VST or AU effect designed for it, like the free tools at www.voxengo.com/product/msed/
Durin then connected me with Matt Stegner, senior quality engineer at Adobe. Matt added:
We support M/S as much as any 2 channel audio format would be supported. ANY DAW can support certain encoding and decoding strategies even if the original designers didn’t have M/S in mind by using effects. Perhaps a follow up question as to what specifically the user is trying to achieve will make it clear if Audition can help or not. I’d be happy to help answer any questions. Audition does have some special and unique tools that make it easier to work in Mid/Side for sure.
Audition’s Channel Mixer effect has presets (Stereo to M/S) to encode and decode Mid/Side. This effect can be placed at the beginning of an Effect Rack chain. Any effect placed after will be encoded in “M/S” (where left is mid and right is side). At the end of the chain the user will need to place a second instance of Channel Mixer effect and use the M/S to Stereo preset to decode back to discrete stereo. Any effect that you place in between will be operating in an encoded Side mode where the left channel will be the mid signal and the right channel will be the side signal.
One unique thing about Audition is that each audio effect, even 3rd-party effects, can be made to operate on just the middle or the side via the Effects Channel Map Editor. If you open any audio effect and press the button in to the effect upper right corner, the effect will switch to channel map editor. If you have done what I mention above, in the channel map editor you can bypass either the left or right channels of any effect allowing you to process just the mid of just the sides or the stereo signal. This becomes very powerful when you start to use 3rd party audio effect to manipulate the M/S of a stereo signal when the original effect did not explicitly envision M/S in its design.
The Audition Effect Rack Presets below all have M/S decoding similar to what I describe above if you want to see it in action.
Larry adds: Thanks, Durin and Matt, for your explanations.