The EM Poll

Producing Pro Podcasts

Dec 1, 2007 12:00 PM, By Mike Levine

           

BONUS MATERIAL
Web Clips: Watch a video tutorial that shows you how to edit and clean up audio for Podcasts

Anyone with a USB mic and a computer can record a Podcast, but if you want to produce a product that will hold its own with the radio shows and other top-shelf downloadable content available on the Web, you'll need both studio chops and an attention to detail. Sonic problems such as uneven levels, background noise, and distorted audio will all have a negative impact on your listeners no matter how good the content is.

As the producer of Electronic Musician's twice-monthly “EM Cast,” I've picked up a lot of useful Podcast production techniques. In this article, I'll try to pass on as much advice as I have space for. For additional information, see David Battino's “The Art of Podcasting” in the December 2005 issue of EM (available online at www.emusician.com). That story covers many general Podcasting issues, such as putting together RSS subscription feeds and promoting your product, that won't be covered here. I will focus on the production side: recording, editing, and mixing.

Your most important tool for Podcast production will be a digital audio sequencer or multitrack audio editor. I recommend fully featured applications like Digidesign Pro Tools, Apple Logic Studio (or Logic Express 8), Steinberg Cubase, MOTU Digital Performer, Cakewalk Sonar, and Ableton Live. You could also do quite well with Apple GarageBand, which has a lot of Podcasting features built in.

Talk to Me

All Podcasts contain at least some voice-overs or other spoken-word elements, and many consist solely of such content. Interviews are one of the best sources of material if you're putting together an informational or topical Podcast.

If you're recording an in-person interview or discussion for your Podcast, I would recommend using a digital 2-track recorder with a stereo mic. There are a number of good, relatively inexpensive models on the market by manufacturers such as M-Audio, Edirol, and Zoom. In a slightly higher price category, you might consider Sony's new PCM-D50, which is a lower-priced alternative to the company's high-end PCM-D1, but which offers similar functionality.

If you have a laptop with recording software and a good USB mic, you could record with that as well. Make sure you can get enough level with the mic you're using; some USB mics do not provide much gain. Another option is to record using a laptop with a portable audio interface and a conventional dynamic or condenser mic.

The Info page in iTunes, where you can edit your ID3 tags.

For both interview and voice-over recording, I recommend using 24-bit resolution whenever possible (at a sampling rate of 44.1 or 48 kHz). Although your final product will end up as an MP3, you want to get the best-quality source recording possible. The increased dynamic range and improved signal-to-noise ratio of 24-bit audio (as compared with 16-bit) gives you the luxury of not having to worry as much about levels that are a little too low. But even at 24-bit, you should always strive to capture levels that are as high as possible without clipping. During interviews, be constantly ready to adjust your recording level down, when necessary, to avoid digital overs. Digital distortion cannot be fixed in the mix, so if you have to err with your level setting, do so to the lower side.

Try to set up your interview in as quiet an environment as possible. Steady or intermittent background noise can wreck your final product. (Beware of air conditioners!) Although there are some methods for removing noise after the fact (more on this later), by far the best route is to get a clean initial recording.

Also pay attention to the acoustics of the space you're recording the interview in. If it's really reverberant, you can minimize that by holding the mic close to the interviewee, and then bringing it close to you for your questions. Try to move it in between questions and answers so that as little handling noise as possible occurs when you or your interviewee is talking.

If you can, do a test recording before you actually start the interview to make sure everything is sounding good. Bring headphones so that you can accurately judge your test recording. Make sure your settings are correct and that the machine is actually recording when your interview starts. There's nothing worse than finishing an interview and discovering that the recorder was in pause mode, not record, for the entire conversation.

Call Me

Telephone interviews are an important part of many Podcasts. They provide the opportunity to bring in the opinions and thoughts of people from anywhere in the world. But recording phone interviews with good fidelity is not easy. While recording phone-based Podcast interviews for EM, I've experimented with a number of different methods. Here are three that I've used, presented in order of preference.

Miking the speakerphone

I've gotten good results close-miking a speakerphone for the caller's voice while separately miking my own voice, and recording the output of both mics onto separate tracks of my recording software. This allows me to use high-quality mics and get pretty good separation. The recording of the close-miked speakerphone sounds surprisingly good, as long as I get good levels without turning the speaker up to the point of distortion. Overall, it's the best method I've found.

Chuck Dahmer
Fig. 1: This drawing shows the basic setup for the miking-the-speakerphone method of phone-interview recording.

To do this, position yourself facing the speakerphone so that your mic is about 1.5 feet from it (see Fig. 1). If you get too close, you'll have too much bleed between your mic and the speakerphone mic, but if you get too far, the person on the other end of the line won't be able to hear you talk. (The only way he or she will hear you is through the built-in mic in the speakerphone.)

Point your vocal mic away from the speakerphone to minimize leakage. Use cardioid or supercardioid mics to reduce both bleed and room noise. As when you record voice-overs, a pop screen on your mic is a must for reducing plosives (“popped” p, b, and other consonant sounds). But even with such a device, some exaggerated plosives will inevitably end up on your recording, and you'll have to lessen or remove them when you're editing (more about this later).

Because there's a degree of leakage in this method, it's best to edit out or mute the audio on your track when you're not talking, and do the same for the other party. This will clean up the sound immensely, and the only places where you may run into trouble due to bleed are those moments when both parties talk at once, the result of which is that you can't mute one of the tracks. I've never found this to be a deal breaker, but it's one of the downsides, along with the aforementioned editing, of this method.