Record multi-track Skype group call on OS X

A friend of mine and I host a weekly podcast and, as it often happens, we speak with our guests via Skype. For a while we had everyone record his own audio, since we wanted to have a separate track for each person in order to get the best possible audio quality. But that was inconvenient, both for our guest and for us, as we had to wait everyone to send us his audio before mixing and editing the episode. Recording Skype’s group call in a conventional way wasn’t a better solution. We’d only have two separate tracks: mine and everybody else’s, This is fine if there is only one person other than me, but it’s not with more guests.
So I started to think on possible solutions, and the best one that came to my mind was to have a separate instance of Skype running for each guest (I’ll explain how to do this later on) and use Ableton Live to record each track and to manage the audio routing.

Ableton Live is quite expensive, though, and if you don’t already have some experience with it that justifies purchasing a license, I’d advise you to check out snkl’s post that explains in detail how to achieve the same result with a much cheaper (but still great) app: Rogue Amoeba’s Audio Hijack 3.

My awesome hand-drawn scheme

My awesome hand-drawn scheme

To manage the audio, we need some sort of virtual audio cables to connect Skype to Ableton Live. The best tool is SoundFlower, so head over to their site, download and install it. However, it is not ready for our purpose right out of the box: we need 2 “virtual audio cables” for each Skype instance, and Soundflower only ships with 2 of them enabled by default (and only one of which, the 2 channel one, is suited for our needs). I managed to edit Soundflower’s plist file to get more.

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