Recording speech at Woodford Folk Festival

I spent the last week volunteering at Woodford, a 6 day music festival, recording speeches and forums at the Greenhouse stage. Topics covered the environment, politics, and social science. They were interactive - 4 radio mikes were passed around in the crowd for audience participation. My job was very simple - take a mono feed from the desk, edit it, export as an MP3, and upload it onto the Greenhouse website (where you can now have a listen):

http://www.thegreenhouse.org.au

Prof Ian Lowe gave the highlight of the festival: Has Human Society Reached it's Limits? (To which he answered "Yes, any questions?").


And my view from the audience:


Codecs
My teammate, Ben, and I were going for minimum file size to make uploading easy so we encoded at 56kbps MP3, mono (half the filesize of a stereo file). The loss in quality is noticeable at this bitrate, but it's not a significant loss for speech. 50 minute files were spat out at around 20MB.

Dynamic Range
Most of the forums had many speakers, talking at different volumes through different mikes, so there was typically large volume differences. There were also regular 'pops' on the P's which would put a spike in the recording. I set my levels when recording so the softest sections peaked at -30dBFS and the loudest ones peaked at -10dBFS.

Knowing quality was not an issue and audio of this nature may be listened to streamed from the web on mobile phones with crappy speakers, I wanted a maximum volume RMS, without clipping. The solution was a hard limiter, limiting at -0.3dBFS (with lookahead). I pushed the limiter so the loud sections hit it hard, with up to 10dB of gain reduction, and the soft sections hit it occasionally - with this, the volumes were evened out, and erroneous pops and handclaps were soaked up. An example: