Since I was just using mine, I thought I’d talk a little about microphones. If you’ve used a combination headphone/microphone that plugs into those jacks on you computer, you probably know that it gets the job done, but it’s nothing to write home about. For serious recording of eLearning narration, web video, voice-over, podcasting, you’ll want something with a little more character.
Dynamic versus Condenser
Most everyday microphones are dynamic microphones. They’re relatively inexpensive and durable, and they don’t need a source of power. They operate sort of like a speaker in reverse, with sound waves hitting a diaphragm, moving an induction coil within a magnetic field, producing a varying electrical signal. Dynamic microphones have limited frequency ranges and the sound they pick up falls off dramatically with increasing distance between the sound source and the mic. However, this makes them good for on-stage live performance or karaoke, though you have to be careful to maintain a constant distance from the mic.
Condenser microphones use two electrically charged capacitor (used to be called condenser) plates, one of which is the diaphragm. Sound waves hitting the diaphragm result in changes of distance between the capacitor plates. Condenser microphones have greater frequency ranges, capturing more depth of the sound. They are not so sensitive to increasing distances between the sound source and the mic, so maintaining a precise distance from the mic is less important. However, they will pick up more room noise, including the echo of your voice bouncing off the walls. They are more expensive than a dynamic microphone, require a source of electrical power to keep the capacitor plates charged when in use, and can be easily damaged by bumping them around.
Dynamic mics are generally omnidirectional (see Pick-up Pattern, next section), and one commonly speaks or sings into the “top” of the microphone, as if aiming it at their mouth, as Robin Williams is doing below. However, with most, but not all, condenser mics, one should speak into the side of the mic, with it seemingly pointing away from their mouth, as David Letterman is doing.
In a controlled environment, and you need to consider controlling the acoustics of the room, such as for eLearning narration or voice-over, I recommend a condenser microphone.
An omnidirectional microphone theoretically picks up sound equally from all directions. The body of the mic, what you hold in a hand-held situation, actually blocks sound from below, but it is basically equal in sensitivity from all sides and from above. This is probably fine for people inexperienced with microphones, and for dynamic microphones which are less sensitive at greater distances.
A cardioid microphone has more sensitivity from one direction. This can help to reduce room noise and echo, though no eliminate it.
Some cardioid mics can pick up sound from two directions, either at the same level or at varying levels. These are called bi-directional or figure-eight microphones, and might lend themselves to an interview situation with two people.
Analog versus USB
It used to be that all professional microphones were analog, meaning the electrical signal that left the mic was analog. These required an analog to digital converter between the mic and the computer, which would also supply power to a condenser mic. Relatively new, and fast gaining in both quality and popularity, are USB mics that plug directly into a computer’s USB port. These typically have the driver software inside that installs on the computer the first time it is plugged in, and condenser mics can get the electrical power they need right through the USB port.
For most of my work, I use a Samson C03U Multi-Pattern USB Studio Condenser Microphone. I guess the “C” is for condenser, the “3″ is for multi-pattern (switchable from omnidirectional to cardioid to figure-eight), and the “U” is for USB. Does anyone know what the “0″ is for?
It’s a great microphone, heavy for its size, but its not intended to be hand-held. It comes with a little (too little, I feel) desk stand, but I use a floor stand with a boom that reaches over my desk. This helps to reduce any vibrations of my desk I might accidentally cause.
It also comes with it’s own sound recording and editing software, but I far prefer to use Audacity (watch for this in a future blog post).
Shop around. I found mine for about $100.
I did have a little trouble getting the driver to install when I first plugged it in. It was taking an inordinate amount of time, and I was impatient and didn’t wait long enough. I unplugged it before it was done. Then when I plugged it back in, since the computer’s registry keys had already been changed, the computer thought the driver was already installed and refused to complete the installation. It’s a scary thing to have to monkey with your computer’s registry keys, but I had to reset them. If it happens to you, try working with Samson tech support. Better, when you first plug it in, go have a cup of coffee and let it do its thing.
There are plenty of other condenser mics in the same price range. But I am very happy with my Samson.
Robin Williams and David Letterman images in Public Domain. Pick-up pattern graphics by Galak76. Samson C03U image by Samson.