Reader Fran Drakes is about to embark on a new audio adventure and seeks advice. She writes:
I know you help with the podcasts at Macworld and wondered if you have any advice for producing clean audio. My friends and I want to start a podcast but after a few tests our sound isn't very good. I hear a lot of background noise, tapping, lip smacking, and pops.
If my humble advice can make for a world filled with better sounding podcasts, I can sleep soundly tonight.
Ditch the headset mic: Unless you spend a lot of money on one (and we're talking hundreds of dollars), most headset microphones sound terrible. Their small capsules on the inexpensive models can't capture the full range of your voice and they're easy to positon incorrectly--either too close or too far away from your mouth. A table microphone with a larger capsule is the far better choice as you can get decent sound from a mic that costs around $100.
Get that microphone off the desk: Now that I've recommended a table microphone, get it off the table. When you leave such a mic in its stand and on the table and then make contact with that table, the vibration will travel to the microphone. Such contact can come in the form of nervous tapping and the use of a keyboard or mouse that's also on the table. Find a boom stand of some kind and attach the mic to it.
About boom stands: If you purchase a boom stand that clips to your desk, you face a different kind of vibration problem. Taps can still travel up the stand and make their way to the mic. One way around it is to place dampening pads between the table and the clip, as this knocks down the vibrations. You can also use a freestanding boom stand that doesn't touch the table. Or, you can attach a shock mount to the end of the boom, which prevents vibrations from getting to the mic.
Secure your cables: When you touch a microphone cable, that sound can travel to the mic as well. Move any cables out of the way. You can do this by wrapping them around the boom and securing them with tie wraps.
Get a pop filter: When you get close to a microphone and use consonants that produce a lot of wind--P, B, and H, for example--you risk creating something called a plosive (as in ex-plosive). Having a pop filter (which is basically pliant nylon mesh stretched around a loop) in front of you can take some of the wind out of your words.
And then there are the settings you use and the way you handle a microphone.
About distance: If you've ever seen your Uncle Harry give a toast at your cousin Mildred's wedding, you know that the general population approaches mic technique in two distinct ways. There are those who hold the microphone down around their navel, and so can't be heard, and others who appear to be flossing their teeth with the thing, thus producing sounds one imagines coming from our earliest ancestors. You're looking for the happy medium.
That medium is to place your mouth 8 to 12 inches from the mic, depending on how sensitive the microphone is. Once you've determined the optimal distance, place your pop filter at that mark. This gives you a very strong clue about where your mouth should be, plus it prevents you from leaning into the mic, which can cause you to overpower the mic and produce distortion.
The clue that you're too far from the microphone is not only lack of volume, but also a lot of room tone in the recorded sound. (Meaning the listener can hear the acoustics of the room you're in.) And if you're too close, you'll pick up mouth sounds like lip smacking and swallowing and, of course, your voice may be distorted.
About gain: If your microphone has a Gain knob, set it in the center rather than cranking it up. Perform some test recordings--making sure to record a section using the loudest voice you're likely to employ during the podcast. Check the input meters as you record as well as the final recording. If any meter goes into the red, your level is too high.
If your voice is terribly quiet you can move the mic's gain knob up a bit or move a little closer to the mic. Or if the mic has no gain control, increase the gain in your recording software or on the audio interface you're using. Any time you twist a gain knob--whether on a microphone, audio interface, or within a software application--to a very high position, you risk creating distortion, which is impossible to remove. Far better to record a touch too quietly. That can easily be fixed in the mix.
Develop good habits: When the recording light is on, any nearby sound can be picked up. This includes air conditioners, fans, street noise, you playing with the hippie beads inherited from Aunt Moonrise, audio alerts from your phone, a toilet flushing upstairs, grunts and groans, the tapping your keyboard makes when you believe you're silently tweeting a friend, a hard drive spinning up, and so on. Mobile phones, even when not engaged in making or receiving a call, can cause a horrible sound when checking in with the cellular network. Turn those off.
I'm not suggesting that you build a sound-proof recording studio in your home or place of business, but do your best to prevent obvious sounds from appearing in your podcast. Hang a Do Not Disturb Sign on your door while you're at it. Later, when you have to edit the thing, you'll be thankful you did.
Spread the word: It can be a little awkward laying down the law to others who are podcasting with you. I suggest you instead send them a link to this article along with a note that reads: "Huh, interesting. Maybe we should try some of this stuff." It can't hurt and, at the very worst, I'll get the rough end of their tongue instead of you.