Multi-track Audio Production

When you begin to create podcasts, you'll probably use a simple stereo audio editing program. As your productions become more professional, you may be tempted to move up to a multi-track audio program. Multi-track systems offer a number of benefits, the most important one being the ability to separate the elements of your podcast onto separate tracks. This, in turn, enables you to work on the tracks individually, applying tailored effects such as EQ and compression to each track on an individual basis.

Things to consider
Now that you're graduating to the world of multi-track recording, the first thing to do is label them appropriately so you know what is on which track. Sure, you say, I'm always going to put my mic on track #1, the guest on #2, and the music on track #3. Well, what happens when you add a telephone hybrid? What happens if you're sick and your buddy agrees to finish off one of your podcast productions for you? Believe me, it may seem pedantic, but labeling your tracks will save you lots of headaches in the long run.

Next, to take full advantage of a multi-track recording setup, you'll need an audio interface capable of multiple outputs and a mixing desk with multiple outputs. Each track can be assigned to a particular input, as shown in Figure 1. If you have only a stereo audio interface, you can still record to separate tracks, provided that you pan the two separate channels hard left and hard right on the mixing desk, and then record the left channel on one track and the right channel on another.


Figure 1: Sony Vegas multi-track software

After you have your audio recorded, bear in mind that the overall level will be cumulative. You have to be careful when you mix all your tracks together so that you don't end up with too much level. This can often happen if everyone talks or laughs at once. Suddenly, you have not one track but two or three, all feeding your master mix. This is why you'll want to think about using a compressor on each track or across your master mix if your software allows it.

Multi-track audio software is different in this manner, in that the effects you apply are not performed on the file. Instead, they are applied in real time as you play back the audio. In addition to being able to apply effects to each track, you can also apply effects to the master mix. In this situation, you could apply light compression to each of the input tracks and then a limiting compression to the master mix to make sure you never go into distortion.

Multi-track templates
If your podcast follows a particular format, for example if you use the same intro and outro music for each show, you can save time by creating a multi-track template that you can drop (or record) your audio into each week. Instead of having to worry about finding your theme music and worrying about levels, you just place the theme music on a separate track and then record the rest of your podcast on separate tracks. When you record using multi-track software, tracks that are not in record mode simply play back, so you'll hear the theme music in your headphones, and as it fades out, you jump in with your introduction.