Input Devices for Home Recording Studio: Microphones, Keyboards, Drum Machines

In order to record music onto a computer, it would be useful to be able to make music in the first place. You can get data into a computer in a variety of ways, but because we're talking about music, let's examine how you would use a musical instrument as an input device, even if that is a funny name to describe an eighteenth-century Stradivarius. A computer doesn't judge your musical talents or tastes, or the aesthetic quality of an audio signal. It doesn't care what style or genre that signal is (in fact, it doesn't even care if it's music at all, in the traditional sense), as long as it meets certain electrical requirements. For the moment, we'll treat music, the artistic stuff, as audio, the language you need to speak to a computer.

Microphones

The most familiar input device is the microphone. A mic („mike“) is like an electronic ear in that it hears what you hear, assuming you're standing in the same vicinity. Its diaphragm and capsule convert acoustic energy (sound) to electrical energy (current), which is sent along a wire. A mic is what you use to record a singer, a pianist, or any other source that produces acoustic sound, including an electric guitar coming out of the speaker of an amplifier.

A mic works intuitively: Put it close to the source, and the recorded sound will sound close up; put it further from the source, and the sound will sound further away, possessing an ambient quality. The one disadvantage to a mic is that because its sound-generating elements are so sensitive to acoustic impulses, the electrical current it produces is very weak. Therefore, it must be boosted by a preamp, and that necessitates using a separate box for best results. Preamps are included on some soundcards, but the best preamps exist as external boxes—an additional peripheral.

Microphones come in two basic types: dynamic and condenser. A dynamic mic doesn't require external power to work; you just plug it into your soundcard, preamp, or mixer, and start passing audio. Dynamics are good for really loud signals—such as cranked up guitar amps or bass drums—and they're ideal for stage performance, but they're not the best choice for all-around recording work. For vocals, acoustic instruments, and other general-purpose studio work, a condenser mic will yield the best results in terms of frequency response (high highs and low lows) and sensitivity (details of the sound). A condenser mic requires external power, called phantom pozver, to work, and that's supplied by circuitry in a preamp or other device. That means you can't plug a condenser mic directly into a soundcard, but the extra gizmo you need to drive a condenser mic is worth it for the quality improvement over dynamics that these mics provide.

In recent years, the price of quality condenser mics has dropped, and manufacturers have gotten quite competitive in delivering many and varied affordable condenser mics to home recordists on a budget. Large-diaphragm condensers are considered the best all-around choice for a mic, if it's your first, or if you can only have one. Companies such as AKG, Audio-Technica, M-Audio, Marshall Electronics, and Shure all offer a wide range of excellent large-diaphragm mics at affordable prices.

Keyboards

An electronic keyboard has an advantage over a microphone in that the signal it produces doesn't need a preamp, so you can plug the keyboard directly into the computer without an intermediary device. You'll still need to hear what you're playing, and for that you can use a keyboard amplifier, headphones, or the computer's speakers—but at least electrically speaking, the output of a keyboard can talk directly to a computer's sou­ndcard or other interface (explained later), assuming the cord's plug correctly fits the interface's jack.

A keyboard is a good master input device to have in your studio, even if it's not your main performing instrument. When you want to input general music information into your computer, regardless of whether it's actually a piano, organ, or other keyboard-based instrument, an electronic keyboard is often the best tool for the job.

Drum Machines

A drum machine is something most computer-based musicians eventually come to own because it produces sampled (digitally recorded) drum sounds that can be played and programmed into patterns and grooves—from single instruments, such as a conga or clave, to a full drum kit. A drum machine not only has drum sounds but also pads with which to play the drum sounds, making it a better device for pounding out drum parts than, say, a guitar or keyboard. If you can't play drum parts yourself, a drum machine also has an onboard sequencer (pattern composer) that allows you to create your own groove right within the machine, though it's often preferable to create the drum patterns on the computer software and use the drum machine in slave (sound output-only) mode.

Electrically, a drum machine's output is similar to an electronic keyboard's and therefore can be plugged directly into the computer's in­terface without the aid of a preamp. You use the same kind of cable to hook up a drum machine as you do a keyboard or guitar. Having said all this, you don't need a drum machine to add drum parts to your compositions. By importing preexisting grooves and patterns from CDs or by assembling drum hits from samples on your hard disk, you can create drum patterns without any drum machine at all. You can also use the preset drum sounds in a keyboard workstation or synth module. But as an input device, a drum machine is a handy thing to have around.