Yes, I am podcasting-obsessed. Not content to simply listen, I decided I had to experience the joy of creating a podcast hands-on. The Cocoon GetTogether 2005 event held in Amsterdam Oct. 5th through the 7th presented a great opportunity, a genuine need. Last year’s GetTogether sessions were videotaped with the intent of publishing the videos on-line, but because of the comparatively high effort involved in producing and publishing video, they never made it onto the web.
With a burning desire to get hands-on podcasting experience, I volunteered on the cocoon-dev list to capture and publish audio for this year’s GetTogether. A few people expressed a desire for video instead of audio, but most shared my keep-it-simple-and-make-it-happen perspective. Another factor is time-shifting: a key benefit of podcasting is its ability to time-shift into any timeslot where our ears and mind are available. Video is more limited for time-shifting, incompatible with a number of timeshifting opportunities such as drive time, workout time, etc.
Choosing the Hardware
The first decision was what hardware to use for audio capture. I had two separate audio capture needs: first, to capture audio from the GT2005 sessions, which meant connecting into whatver A/V equipment they had at the NEMO Science Museum where GT2005 was being held; and second, to capture audio from interviews, ideally with two microphones on separate recording channels. Plugging a microphone into the jack on the laptop was definitely not going to cut it.
My first thought was to use my home music studio setup, which features Pro Tools and Reason software, Mbox hardware, various studio microphones, etc., which would be more than adequate quality-wise for recording and producing podcast audio. The problem is, this setup isn’t very portable, and furthermore my kids use the studio a lot and would not be pleased to have it disappear for a week while I was in Amsterdam. Finally, my current laptop is pretty lame, and I wasn’t sure it could even run Pro Tools, which is notoriously finicky about hardware and OS configuration.
The best portable platform for pro-quality podcasting is probably a PowerBook paired with a FireWire-based recording interface like a PreSonus Firepod; and in fact I’ve been looking for an excuse to buy a PowerBook … Unfortunately, the timing was really bad, with Apple overdue to release a new PowerBook line. (They’re still overdue!)
I decided to make a trip to Guitar Center, a major US music chain with a strong professional audio department. When I walked in the door, I was leaning towards buying the latest Mbox or maybe a Firepod; but then the pro-audio guy showed me the just-released M-AUDIO MicroTrack 24/96.
Just a tad larger than a full-size iPod, the MicroTrack captures professional-quality audio in WAV or MP3 format. It has two 1/4″ TRS jacks for stereo recording using pro-grade microphones; with the right cable you can connect XLR-cabled mics, even condenser mics that require “phantom power.” These same inputs can connect to the line output of a mixer. Recordings are saved directly on Compact Flash storage; I bought a 2GB card, which has a 30+ hour capacity when recording to MP3, or 3+ hours to WAV. The MicroTrack has a USB 2 port, and when you it plug it in, it looks like a USB hard drive. It looked pretty much perfect.
I already had one Audix OM-2 mic, so I bought a second one, a couple of table-top mic stands, the right cables, and a whole raft of adapters so that I could connect to pretty much any A/V hardware that they might have at the NEMO. The whole setup fit into one compartment in my laptop bag—most of the space was taken up by cables and microphones.
On-site in Amsterdam
The MicroTrack worked like a charm. I did interviews during the Hackathon on October 5th and 6th; it is ironic that a single microphone is larger and heavier than the MicroTrack!
Also on the 6th, Arjé Cahn (hippo.nl) and I travelled by bicycle over to the NEMO to check out their A/V setup in their theater where the next day’s presentations would take place. The theater was nicely equipped with a full pro sound system including a Mackie mixer, so interfacing was a snap.
On the day of the GetTogether itself, October 7th, it was just a matter of plugging in, pushing the record button, and keeping an eye on the input level displayed on the MicroTrack’s LCD display.
On-the-fly Production
My original plan was to capture audio files in large but lossless WAV format, bring them back to Chicago with me, and do post-production using Pro Tools. But in Amsterdam, I decided to switch to MP3 recording, because the WAV files were pretty unwieldy—a single 20 minute interview could generate a 150MB file, which was then slow to copy or FTP around. I also downloaded and installed Audacity, an open source audio recording and editing tool, to see if I could do the audio post-production right there in Amsterdam.
Audacity worked well overall (see one possible caveat below) and enabled me to edit the audio immediately as sessions were recorded. We nearly achieved same-day publishing, but the NEMO’s network crapped out at the last minute on Friday and I didn’t get things uploaded to the GT2005 site until Sunday.
John Berry pulled together the podcast’s RSS feed, and I was able to test subscribing under iTunes and synch with my iPod. The result looked and sounded good; and as they say on TWIT, the podcast was “in the can.”
Lessons Learned
- Interviews require careful preparation. I tried to “wing it” but soon realized that both I and the person being interviewed needed to understand what the questions were going to be, in advance, otherwise it would be very easy to stumble around, run into unhappy subjects, etc.
- Audacity downsampling troubles. Somehow I managed to introduce some voice distortion when I took the original MP3 files (captured at 128K) and downsampled them to 64K. This might be a limitation of using MP3 (rather than WAV) as my source format; or of Audacity; or just a problem with how I went about it. I haven’t had time to diagnose yet, but plan to.
- Gain is key, and MP3Gain is nice. I learned that getting nice fat gain on your MP3s is important, and that the MP3s coming out of the Microtrack tended to be low-gain. I found another piece of open source software called MP3Gain that does a nice job fattening up the gain.
- Don’t forget to set the ID3 tags on the MP3s. When I compared our podcast with those produced by IT Conversations inside iTunes, I noticed that theirs had Artist listed while ours didn’t. At first I thought this information was being pulled from the RSS feed, but later determined it actually comes from the ID3 tags in the MP3 files themselves. Next time I’ll remember to set those …
- Consider capturing WAV versus MP3. I have great respect for Doug Kaye at IT Conversations, and apparently they capture audio as WAV rather than MP3. I’m still not sure if this is a must; it might even be an artifact of the devices and software normally used to capture audio. But next time around I’ll definitely rethink WAV versus MP3 recording
- iPod earbuds are NOT for audio editing. Actually, they’re not really that good for anything…. Get some good quality headphones!