Digital Audio Mastering for Your Podcast

MP3 - Motion Picture Experts Group - Layer 3

The standard digital audio format for podcasts is MPEG 1 Layer 3, commonly referred to as MP3. MPEG stands for Motion Picture Experts Group. There are different measures of quality within an MP3 file. As a podcaster, you will want to select a quality that both sounds great but also downloads quickly for listeners.

If your podcast is mostly voice with no background music or musical segments you may want to consider using a mono file as this will reduce the MP3?s file size and as a result, minimize your podcast's download time even more.

AAC - Advanced Audio Codec

Apple's software enabled AAC encoded podcasts to use chapters, bookmarks, external links, and synchronized images displayed on iPod screens or in the iTunes artwork viewer.

Action: Export Your Recording as an AAC file

An alternative for creating more interactive podcasts is using Apple's proprietary AAC format. AAC stands for Advanced Audio Compression. The AAC format does sound better. However it can only be listened to in Apple iTunes and on Apple iPods.

If AAC isn't one of your export options, you can convert an MP3 into an AAC file by using Apple iTunes.

Check Your Mix - Review your podcast

See if your mixed down MP3 sounds good on a variety of stereo systems such as your computer speakers, headphones, portable stereo and car stereo. If your mix translates well from system to system, you know that you have created an excellent work of art.

File Conversion - Converting to MP3

Whatever recording program you are using, you will have the option to save or export your recording as an MP3. If the only option is to export as a WAV file, that's OK too. You'll just have to complete one extra step to convert the WAV file to an MP3 file.

Structure for Saving Podcast Episodes

Here's a tip: organize your podcast episodes by creating a simple file folder structure

Save time by getting organized right from the start. Create a file folder in "My Documents" called "My Podcasts". In your "My Podcasts" folder create new folders for each episode in advance such as "Episode 01" , "Episode 02" , "Episode 03" etc... Having a defined structure for your podcasts will not only keep you organized but will help you plan shows in advance. Whenever you find an interesting story, come across a press release, or think of a great idea, you can save it directly into the folder for that specific podcast. When it comes to planning and recording future episodes, you will already have some content that you can use as a starting point for your next episode.

When saving your podcast episodes, export your podcast recording as an MP3 file. Save the file as 'Podcast_Episode_01.mp3'.

Digital Audio File Sizes - File Tips

WAV or AIFF files uncompressed pure audio in PC and MAC format huge files with great quality

MP3 or AAC compressed audio - much easier to stay within your bandwidth limit much smaller

To encode audio you need to set:

the bitrate - kbps
the sample rate - kHz (44,100 is standard MP3)

A professional sample rate will be much higher kHz. The sample rate is a basic measure of how closely the sound is to the original. The smoother and clearer the sound is, the higher the rate is. Most podcasts range from 10 minutes to 1 hour. Here?s a chart that will give you a better idea of the file sizes for each show.

Summary - Key points about Mastering Digital Audio

In this section, we discovered how easy it is to make your podcast sound exactly that way that you envisioned it to. After mixing and mastering your podcast, you will be rewarded with your very own podcast-ready MP3 file. If some of these elements are not within your areas of expertise, the next chapter will provide you with solutions to your podcasting needs, offering helpful ideas and qualified parties to outsource elements of your podcast to.

 

Next: Hiring a Podcaster