As a recording engineer in training, you'll have to know a little bit about sound waves and electricity, because they are pivotal to understanding recording. In this chapter, you'll see why it's impossible to separate music from science — the terminology is everywhere, impossible to escape. Have no fear!

Sound Waves

Sound is emitted by a source and travels in waves that vibrate back and forth pushing air molecules around them. The sound waves create sound pressure (volume) as they push through the air molecules, which make our eardrums vibrate and pick up sound. Without a medium for sound waves to travel through, there is no sound.

The speed that a sound source (a monitor speaker, for example) vibrates tells you the frequency of the sound that comes out. If a speaker is playing a perfect A (440Hz) tuning note, such as one found on metronomes and tuners, it is vibrating back and forth 440 times a second. The faster the source vibrates, the higher the sound; the slower it vibrates, the lower the sound, or pitch, you hear. Sounds are rarely made up of just one frequency; actually there are many frequencies present in any one sound. The science behind it is beyond the scope of this book, but just understand when you play or sing one note, there's more than just one frequency present.

You might be saying to yourself, why do I have to know this? That's a legitimate question, and here's the short answer: Understanding frequency and how sound works is essential to mixing and most all effects. We don't just talk about “low sounds”; you'll see on your EQ knob that “low” might have “80Hz” next to it. Your microphone might have a “100Hz roll off” on it. You might read an article about boosting the 10kHz band to improve presence and clarity. Wouldn't you like to know what that all means? Simply put, the audio community, which you are now a full-fl edged member of, deals with terms like hertz and kilohertz, so you should simply learn what they mean to avoid confusion!

Ranges of Sound

Let's talk a bit about the ranges of sound you might be used to. Your stereo might have a bass and treble knob. These knobs are used to boost or cut a certain range of frequencies. The specific range of frequencies involved will differ from system to system, but this is generally known as equalization (or EQ). EQ is simply the boosting or cutting of certain frequencies of a sound. The most basic EQ you will encounter is a three-band EQ on a mixer (either outboard or virtual).

As you can see in FIGURE 13-1, there are values in Hz next to the knobs. The values show what ranges of sounds are affected by turning those knobs. If you really want to learn about EQ, twist knobs and listen. Like any other skill, you need to practice. Don't be afraid to grab knobs and listen to what happens.

Effect Types

There are a few different types of effects that are utilized in studios. The first, equalization (EQ), isn't really an effect per se, but for our purposes, we'll lump it in with the rest. EQ comes in many flavors, from a simple three-band EQ found on many 4-tracks and mixers to elaborate parametric equalizers that give a great deal of control over individual frequencies. Dynamic processing involves effects that control the volume or dynamics of sounds. Effects like compression, limiting, gating, and expanders all control the volume of tracks.

Special effects usually encompass delay and its many incarnations, such as tape delay, and multitape delay. Modulation effects like chorus and phasers and flangers change the sound by utilizing a delayed signal mixed in with the original signal, which either delays that signal or changes how the delayed signal sounds. The mixture of the two signals is the characteristic sound of modulation effects. Reverb is the most important effect to learn how to utilize well. Every sound we hear has some reverb. Reverb, which is short for reverberation, is a natural occurrence when sound waves reflect and bounce off surfaces. The larger the room, the longer it takes the sound to come back to your ears — giving you the feeling of space and distance. Reverb is such an important part of acoustic sounds that when we record without it, it sounds quite strange. It is possible to emulate the sound through reverb processing, giving you the feeling of space.

Hardware vs. Software

Years ago, effects were done exclusively by outboard effects units that were rack mounted. Certain effects processors were multifunction units and could produce reverb, delay, and other effects all within one unit. Other gear was more specialized to one job, like a compressor for instance. The great part about outboard gear is that it sounds really good. Many studios still use them instead of computer plug-ins because the engineers feel the sound is better.

Early outboard gear used analog technology to produce the effects. As technology improved, manufacturers turned to digital signal processing (DSP) chips to improve the quality of the sound. The digital-effects processor was born. It was only a matter of time before a computer was able to do the job of DSP. Indeed, that day has come. Now, instead of needing floor-to-ceiling racks of gear, you can re-create all the effects you want through software. This is where the home studio became powerful. No longer do musicians need all the space and expensive gear! Now, through software, a computer (or a studio-in-a-box) can do it all.