Podcasting Howto: workflow for recording and improving sound quality for a podcast using Audacity

This howto is entirely based on David Taylor‘s excellent Introduction to Audacity youtube lesson. With apologies for the boring soundcheck used in the examples.

Preamble

  1. Install Audacity and the LAME (.mp3) and and FFmpeg libraries following the instructions from the website.
  2. Have a mic of some sort ready and plugged into your computer.
  3. Have headphones ready too.
  4. If you haven’t done this for a while, re-watch David Taylor’s introduction to Audacity to refresh your memory.

Setup

  1. Plug in mic and turn it on.
  2. Open Audacity.
  3. Decide whether you want to record in stereo or mono (smaller files), using MME, with project rate set to 44100Hz.
  4. Shut door, turn off fan.
  5. Mic check – check that audio doesn’t go above -0.0db on the meter.

Recording

  1. Click record.
  2. Wait for 3 seconds to capture ambient noise.
  3. Start speaking – be spectacular.
  4. Click stop.

Post-production

.wav file of the raw audio
  1. Zoom out to see entire clip; zoom in on ambient noise section.
Noise Reduction

Noise reduction gets rid of some of the background hissing and ambient noise to clean up the sound of your recording.

  1. Select the empty three seconds, then: Effect>Noise reduction
  2. Click Get Noise Profile.
  3. Select the entire clip (manually or using Control A then Effect>Noise Reduction. Click preview. If it sounds okay, click okay. It makes a huge difference in the project file, but less of a difference in the final .mp3.
  4. Trim off the empty three seconds.
Post noise-reduction
Normalisation

Normalisation brings up the sound levels so that they’re consistent across the recording.

  1. Effect > normalise. Use -2.0 as standard.
Normalised to -2.0 decibels (i.e. made louder)
Equalisation

Equalisation can help increase or reduce key frequencies in your recording – for example by getting rid of excessive bass or treble.

  1. Effect > Equalisation. Click equaliser to show sliders. I used AM radio to reduce sibilance but bought up the treble a bit.
  2. I tried again using the voice setting but bringing down the treble too. Not sure if I can tell the difference.
Post-equalisation using AM Radio setting, with a bit more treble
Post-equalisation using voice setting, with a bit less treble
Compression

Reduces the dynamic range of the recording (the difference between the loudest and quietest parts) – it can make the audio sound better when it’s amplified.

  1. Effect > Compressor.
  2. Uncheck Make-up gain to 0DB and uncheck Compress based on Peaks.
Re-normalisation
  1. Normalise again to -2.0
Other tweaks
  1. For any too-heavy peaks or plosives, zoom in and select them, then use Effect > Amplify and reduce the gain for that section.
  2. Use silence to remove any breaths etc.

Export to .mp3

Export as .mp3 using these settings:

  1. Export to mono for a podcast
  2. Constant Bit Rate
  3. Either 64 (common

Recording and editing with Audacity – start here

I had another go with Audacity this weekend and came across this tutorial for absolute beginners.

David Taylor‘s introduction is clear and systematic. He tells you everything you need to know to record, edit and tidy up audio in a little over fifteen minutes – fifteen minutes very well spent.

I like that it assumes no prior knowledge, covered everything you need to know with some nice details, and ignored the rest… and treats you as a beginner but not an idiot.

I’m convinced. My recent adventure went far better than my first try, and Audacity will almost certainly be my tool of choice for making the next episode – or prototype episode – of the DC podcast.

Thank you David!

P.S. There’s an reference in the video to Son of Citation Machine, which looks like a good resource…