If you’re like me, as soon as you’re able to pull off a few goods licks on your instruments of choice, you’re going to want to record. And then, much like me, you might find that your first try at recording doesn’t come out nearly as pro as you expected. You might be thinking, what gives? What exactly makes a recording sound professional? It can’t possibly be just as simply as hitting the record button, can it? Well, depending on the music – and under perfect conditions that take into account a few different things – it actually can be that easy. Songs that simply feature a singer and guitarist, such as folk, can be done this way, but chances are that’s not the type of recording you’re thinking about. And with that said, the great majority of recordings that most people think about employ a ton of the available gadgets that are used to tame or sweeten the sound coming in and going out. These devices are called effects processors and come in both hardware and software incarnations. You've probably seen them in photos of pro studios. There are a number of different types of effects. Some are utilitarian and meant to control a signal being recorded. Others are designed to artificially add a sense of space. Still others can be thought of as 'wow' effects that are used to add interest and excitement to a recording.
Since most popular hardware effects had already long been based on digital technology, effects processors were among the very first to get the software emulation treatment and accounted for the bulk of the first wave of plugins to hit the market. The industry was soon prevalent with both emulations of classic effects and entirely new processing tools that took full advantage of the power of modern desktop computers. Most software sequencer packages come bundled with the essential effects, and there are plenty more to be found, many of which you can check out right here at ProAudioLand.
Reverberation is an ever-present effect - you hear it all around you every day. It is simply the ambience of any environment, either natural or artificial. You can’t have failed to notice, for instance, that your voice sounds different in a stairwell than it does in a tiled bathroom (which is why people like to sing in the shower). That’s because sound bounces off the smooth surfaces and moves around each space in a specific way. Reverberation simulates this effect, providing lots of emulated environments that you can use to give your tracks a sense of space.
Reverberation comprises many tiny echoes that bounce off surfaces and return to the ear at different times, with changes in pitch and volume. Manufacturers have utilized different approaches to achieve this effect. Older hardware units might bounce the sound off a suspended metal plate or metal springs in a box. Many digital reverb processors do it by creating and manipulating a number of echoes. Convolution or ‘impulse’ reverbs use mathematical analyses of signals in real spaces that recreate the effect on an incoming signal. Usually you can control the decay or room size, the amount of delay before the echoes and more. Reverb can be used on everything you want to put in a ‘space’. Use it sparingly on lead vocals and instruments, since it will cause them to sound further away. It works great on drums to give a sense of ambience and cohesion.
Delay is one of the simplest effects and, in fact, serves as the basis for many other more complex effects. A delay processor does exactly as the name suggests: it delays the incoming signal, sending it out later than it came in. Sometimes it’s used as a corrective tool - more often, however, it serves as a sound-enhancing effect. When combined with the un-delayed signal, it creates an echo effect. Sometimes many copies of the echo will be present, and (usually) each will be successively lower in volume than the one preceding it. You might hear this effect on, say, the last line of a vocal, or on a guitar line (think U2 or David Gilmour).
A delay works by copying the signal and then playing the copy back after a user-specified period of time. Old delays were made by using one or more tape machines and changing the distance between the record and playback heads. Digital versions abound, since playing back a copy is not a difficult task for modern computers and software. You will often get control over the delay time, feedback (the number of echoes) and mix between the original and delayed signals. Sometimes there will be some control over the frequency content of the echoes; this simulates the interesting and characterful degradation inherent in old tape-based units. Short delays sound terrific on vocals and were often used to treat the vocals on John Lennon and Buddy Holly records just to give two examples. They also sound great on rhythm and lead guitars, and on synthesizer passages.
A compressor is a dynamics processor - it helps to maintain a steady volume even when the incoming signal is fluctuating wildly. Have you ever wondered how a singer can seem to go from a whisper to a scream without any drastic change in overall volume? That’s compression at work. Put simply, it makes the loud parts quieter and the quiet parts louder. Its near-twin, the limiter, only does half of that: it keeps the loud parts down. Famed producer Tony Visconti (T-Rex, David Bowie) once called compression “the sound of rock”, and he wasn’t far off considering how much it’s used. Compression is also used all over modern music (some say too much), and is a sort of secret weapon for achieving a professional sound.
Compressors can be difficult to comprehend until you put them to use. They vary in complexity, with the simplest vintage-style examples having only input and output knobs (turn the former up and the latter down for more effect). Others provide a user-definable volume threshold above which the effect will kick in and a ratio that describes the difference between the unprocessed (or ‘dry’) signal and the effected (or ‘wet’) output. The higher the ratio, the greater the effect. A setting of 1:1 does nothing, while a setting of 12:1 is pretty drastic. There may also be a way by which you can control how fast the compressor works; this might be accomplished with attack and release parameters, for example. Use compression on everything that requires taming. Vocals are a given, unless your singer has great mic skills. Drums, too, can be molded into shape with a compressor. Entire mixes are often (over-)compressed to make them sound louder. Go easy, though - too much compression or limiting can suck the life out of your tracks.
EQ and Filters
An EQ allows you to control the amount of low-, high- and mid-range frequencies in your tracks. Some are simple bass and treble controls, while others are splayed across eight, 16 or even 32 frequency bands, each with a slider to cut or boost a specific frequency or set of frequencies. EQs and filters are essentially the same thing, except that a filter is designed primarily to attenuate (or reduce) rather than boost the levels of specified frequencies. These tools allow you to shape the tone of your tracks - a good mix is one where the various sounds don’t crowd each other out, and an EQ or filter is designed to help tame or emphasize frequencies to achieve this.
EQs and filters give you one or more controls that boost or reduce the level of a specific frequency. Filters are the simplest - they usually provide a single ‘cutoff’ frequency above or below which the signal will be filtered. A low-pass filter allows only frequencies below the cutoff frequency to pass through; a high-pass does the opposite. A filter sometimes allows control over ‘Q’, which determines how precise it is. EQs have Q, too, though it’s often called bandwidth. Some equalizers only affect preset frequencies (graphic EQs are like this), while others are parametric, meaning they allow you to choose which frequency is boosted or attenuated. Apply equalization as a way to make room in your mix or to correct for missing frequencies in your recordings. Do your vocal and guitar fight for dominance? Cut the upper mids in the guitar to make room for the voice.
Chorus, flanger and phaser effects are all considered modulation effects. Flanging sounds as if the frequency spectrum is sweeping up and down. The Small Faces’ Itchycoo Park contains a classic example of the sound, though it has been heard in many other places, too. Chorus effects do just what you think - they simulate multiple copies of the input signal playing simultaneously, though each with a slightly different pitch and time. Nirvana’s Come As You Are is rife with chorused guitars. Phasers sound similar to flangers, but there is a sweeping ‘notched’ sound in play, giving them their characteristically metallic, piercing tone.
Each of the above effects makes use of copies of the incoming signal. A phaser alters the phase of the copy with one or more all-pass filters. The number of filters is defined as the number of ‘stages’, and will affect the depth and richness of the sound. A flanger is very similar, except that the copied signal is delayed by a few milliseconds. This results in a sort of ‘jet engine’ sound. Similarly, a chorus makes use of at least one copy of the original signal and plays it back at a slightly different pitch, and usually with some amount of modulation as well. The most important thing to remember with these effects is that they are exactly that -- effects. Though in some cases (most notably the chorus effect) they attempt to emulate real-world techniques, they sound artificial and synthetic. They are ideal for sweeping guitars, electric pianos and even the occasional bass track.
Engineers spend thousands of dollars to ensure the truest, purest recording of the source material, while the material itself might be an unholy wail of screeching, fuzzy guitars or distorted vocals. And some engineers insist on recording the best singers in the world through tube gear that adds yet another level of grit and grime. Let’s face it: we like distortion. We like raw, rough, crunchy sounds that spit and growl. And we get these sounds through various types of distortion effects, such as overdrive, fuzz and clipping.
Distortion happens when a signal exceeds levels that the gear it’s passing through was designed to handle. This causes, in some cases, overdrive. Overdrive can be subtle, like when using a tube microphone or preamp, or dramatic, like when your guitarist cranks his stack up to 11. When the signal gets too hot to handle, it ‘clips’. Too much clipping results in an unpleasant sound, but that may be just what you want! Other sorts of distortion might not be so appealing - digital clipping sounds terrible. However, even that might find a place in some forms of music. Obviously, distortion doesn’t require us to buy costly studio gear - there are plenty of stompboxes, real and virtual, that can give you the grunge you need. Distortion is primarily used for guitars, but it can also be very effective on vocals - just ask Trent Reznor. Used subtly, it can spice up digital drum tracks or loops too, and some people even love the sound of fuzz bass.
It used to be that when a singer missed a note in the studio, a punch-in or re-recording was necessary to correct the mistake. Thanks to a modern miracle of software technology producers are now blessed (or cursed) with pitch correction effects that can snap any off notes to a specific pitch. When used as intended, you can rarely spot them, but when they’re pushed to extremes, the ubiquitous ‘Auto-Tune effect’ is achieved. Simply turn on any hip hop station for an example of that one, not that you probably need one. Not to be confused (though it usually is) with a vocoder, the Auto-Tune sound is synthetic, gargling and, honestly, done to death.
Originally made famous by Antares, there are loads of variations on the original Auto-Tune processor. There are even freeware variants on the effect. Most of these allow the user to specify a musical scale or play one in via MIDI. Any notes that fall outside of the scale will be shifted to the nearest note in that scale. Some pitch correction takes place offline, not as you play the audio. Celemony’s Melodyne is like that - it allows you to change not only the pitch but also the duration of individual notes by moving them around a grid. Impressively, it even works on chords. Uses for pitch correction depend on what you want to achieve. If you need to correct a few notes of a voice or other monophonic instrument, it can save you time, and Melodyne makes a great tool for writing vocal harmonies. If you want that sound, though, you’ll slather pitch correction all over every vocal in sight.