I’ve had an idea for a book in my head for a few years now. Since there is a challenge afoot, I started, November 2, 2010, to write that book. This blog will contain the very rough draft and I hope I’ll get a chunk of it out this month. No guarantee I’ll write everyday, but I hope this won’t be the last entry.
I used to work in local television. Since my background was church tech, I was always curious about the engineering behind the video. When I started, all commercials were run off of a GrassValley video server. I made sure I learned how. It’s actually surprising how much equipment is needed for professional broadcast and how little for even a high-end video podcast.
A Face for Radio
So let’s say you want to do audio only. Maybe your content is best in audio form or you just want to get started. Either way, you can start very simply by plugging a microphone into your computer’s sound card. You’ll need some audio recording and editing software to make this work.
There are several pieces of software, but let’s start where most podcasters start–Audacity. Audacity is an open-source project that allows for modest recording and editing. People have edited audio professionally find it limited, but the price is right. It’s cross-platform, running equally well on Macs and PCs.
I should mention that Apple’s GarageBand which is free with new Macs (or can be purchased with their iLife suite), has some features that have been added with podcasters in mind. Add to this the capabilities to create the AAC files with auto-advancing stills, and you have a powerful tool for audio editing newbies.
I’ve purposely omitted talk of computer hardware because my experience tells me that computers built in the last ten years tend toward more than enough power to do the recording and modest editing that most audio podcasts require. Should you run across a computer with no audio input or a bad audio card, replacements are available along with usb “cards” like the Griffin iMic which can cheaply fix this issue.
Let me note here that interference can ruin an otherwise great recording. A noisy power supply on a computer is a common culprit. Should you run into a situation where plugging your mic into the sound card results in interference, a usb mic or a usb sound card will often fix this. We’ll cover other sound problems later.
Don’t hesitate to buy circumaural (around your ears) studio headphones. These are often much more expensive than you’d think if you’ve never done professional audio before, but the ability to provide some isolation from outside noise during the recording and editing process can be invaluable. Sony makes entry-level headphones that provide better sound reproduction than the free ones that came with some other device, but won’t break the bank. For the sensitive ear (or really deaf ones) much more expensive headphones might be required.
A good microphone is a necessity. To start off, on a limited budget, you can begin with a computer headset mic. This shouldn’t be the goal, though. There really is a reason why some microphones cost $5 and others cost $200 and others $2000. With the future in mind, let’s look at some of your choices.
While there are others, there are two types of mics that you should look at for audio podcasts–dynamic and condenser. Dynamic mics as their name suggests, produce sound as a result of movement. In this case, there’s a diaphragm that that moves in response to the sound from your voice. These mics are rugged and require more sound to produce a signal. When you think of a handheld mic, the Shure SM58 is likely the one you think of. It’s an industry standard and has been used by bands and public speakers for years. The 58 or a similar mic usually runs about $100 (give or take) and will serve you for years.
Condenser mics, in contrast to dynamic mics, require power (either supplied by an internal battery or phantom power supplied by the audio mixer or sound board). These mics require less sound and generally reproduce sound across the audio spectrum more evenly.
If you’re serious about audio, you should know that radio people swear by the large-diaphragm mic. This type can be either a regular dynamic mic or a condenser-type, but has a larger diaphragm which produces a more full-bodied sound. For male voices especially, there’s nothing like a large diaphragm mic to produce that warm tone.
A basic show can be created with just these tools. It can be just that simple. In fact, quite a lot of podcasts are that simple. I’ve created shows with this basic system. The power of audio podcasts comes when you add hardware to speed up your process.
It’s possible with most audio editing software to add compression, a gate, and add audio effects and prerecorded elements, like a show open and close. This isn’t how it’s done live, though. The reason is that editing takes time. Every piece that can be done without editing saves you time. When I was in television, we called it live to tape. We’d record a news segment as though it was live and be done when it was done. By contrast, editing together a show would take easily twice as much time, but often much longer.
In natural speaking, we have quiet moments and loud moments. Imagine that this is a wave. The loud parts are the top of the wave. The quiet parts are toward the bottom of the wave. Now imagine you could shorten the distance between the two so that there was less difference between quiet whispers and loud yelling. This might not be all that desirable in some circumstances, but imagine that you’re listening to a program and you adjust the volume to a comfortable listening level. Now the person speaking starts shouting. Your ears begin to bleed, you’ve just ruptured your eardrum. Okay, so that doesn’t happen all the time, but you can imagine it happening and even an uncomfortable drop or raise in volume is too much. A compressor fixes this.
This does introduce a problem though. All sounds are not equally important. God in His wisdom, has created our brains to filter unimportant sounds in 3D space. A recording is flat, though. A speaker’s nervous tick of tapping the desk might be acoustically a similar volume as their whisper, but a microphone doesn’t know this. In fact, if you compress the sound so that quiet sounds are less quiet in reference to the loud ones, this problem is compounded. This is where a gate comes in.
A gate is set so that a sound has to be a certain volume for a certain duration for it to pass to the next stage. This means that often quiet background sounds in a properly gated set-up aren’t audible at all. Be careful, though because too much off this can cut off parts of words only letting through the loudest sounds. This produces an unnatural staccato sound.
De-Essers are a nice addition if you know that the “s” and other sibilant sounds are a problem, but often a simple pop-filter (which will also quiet the plosive sounds like “p” and “t”) will passively prevent them.
A single mic can easily be run through a couple of hardware “effects” before going into your computer for recording. When you add a cohost or prerecorded material, this becomes more complex. This is where a mixer or “sound board” comes in. This piece can be as simple as a couple of channel Behringer Eurorack UB502 or as complex as a 48 channel digital board with on-board effects. Either way you can take multiple inputs and combine and mix them for a single output.
All of these pieces affect the sound, but how do you add preproduced content to something you’re recording. You could record and then add the audio later, but if you’re trying to save time, why not do it live? Today, this is much simpler than in the past. Imagine that you have an mp3 player. Plug that into a mixer with your microphone and set up a playlist with the pieces you want to use. Now, cue up your show open, play it and pause at the end. Turn up your mic and you’ve got a basic episode.
For a moderate “studio”, this is great. To take it over the top, you really need a dedicated space. Ideally, this space would be engineered to reduce outside sound and standing waves. Another great way of reducing sound is also to get rid of anything that produces sound unnecessarily. Start by replacing your computer with a device that will record sound. A couple of entry-level choices are the Zoom H2 and H4. These provide on-board mics that can be used in a pinch, but also include a place to plug in an external mic or a mixer.