Moving at the Speed of Creativity by Wesley Fryer

Ustreaming with multiple local mics and remote callers via Skype

This evening I recorded a 30 minute webcast over Ustream with members of my family, discussing their experiences in the past few months reading ebooks on their iPhones, iPod Touches and Kindle readers. We included my father in our conversation, and “skyped out” to him on his landline phone in Kansas early in the webcast. In the past when I have webcasted with Ustream and Skype, I’ve followed Ryan Gordon’s instructions (PDF) and utilized Audio Hijack Pro, Soundflower, and Skype to bring in remote participants in the conversation. Tonight was different, however, since we would primarily be using audio from a local panel of speakers and only temporarily need to use audio from Skype. With Ryan’s procedures, audio from Skype is routed to Soundflower, which is then used by Ustream. Since I didn’t want to keep a Skype call open for the entire webcast, I needed to use a different audio routing setup which would keep our local microphone audio going to Ustream even when a skype call was not in progress.

This need required a different setup in Audio Hijack Pro, and I’ll readily admit I have very little idea about what I’m doing tweaking these settings. The screensnap below shows the eventual setup we used tonight. This DID work, but the audio didn’t sound nearly as clean as I’m sure it could.

Audio Hijack Pro Setup

In addition to this audio software setup, we used a M-Audio Mobile Pre with two local microphones, a phantom powered Audio-Technica XLR boundary microphone, and my Shure PG-58 mic. This was one of the first times I was able to take advantage of the Mobile Pre’s dual XLR microphone inputs, as well as its ability to provide phantom power to a microphone. This sounds really fancy, but until I figure out how to tweak these settings better I don’t think our recorded results sound NEARLY as good as they should. I used the PG-58 and my audio level seemed comparatively low. Shelly and Alexander both shared the boundary microphone, and once I boosted their output level on the Mobile Pre their audio sounded pretty good. There was quite a bit of background noise, it seemed, early in the webcast when we were using Skype, and I used headphones to hear the Skype audio, so unfortunately neither of our face-to-face panelists could hear our Skype caller. (In this case, my Dad.)

The above graphic shows that I hijacked the default system audio, which was the Mobile Pre’s audio feed, and ran it first through a low-pass filter. I am not sure if that filter was necessary or not. Next we added the hijacked audio from Skype, which was also using the Mobile Pre’s audio as its input. Third, we used the “monomizer” filter to bring both channels of audio together in a single audio channel. Last, we used the “Auxillary Device Output” effect to send the entire audio stream out to Soundflower. Soundflower was the audio source I utilized in the Ustream broadcast.

I briefly tried to utilize the Audio Hijack Pro manual to figure out how to combine these audio sources, but I don’t think I learned much there. Rather than have all my audio sources on the top line of the Audio Hijack Pro “grid,” I think I need to keep my local Mobile Pre audio on one line and the Skype audio on another, and then bring them together at the end when I send them both to SoundFlower. I’m not sure how to do this, however.

If you have any suggestions for how to make this audio setup cleaner, more professional sounding, and perhaps a bit simpler, I’d love to hear them! Next week on Wednesday my kids and I are going to try and share a webcast about our favorite iPhone and iPod Touch applications, and we will likely try a similar setup so we can bring in some guest callers / presenters over skype during the call. Hopefully we can figure out how to make our Audio Hijack settings better between now and then. Your input will be most appreciated!

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