Equalization - or EQ - can seem like a bit of a dark art when you start recording your own music. Most of us are familiar with it from the little EQ sliders on the front of our stereos. But what does it really do? And how can a knowledge of it help musicians and home recorders? In this three part series, Graeme Allen explains all.
EQ (or equalization) with in a music tech context is basically the process of altering the volume of certain frequencies in a section of audio recording.
A basic form of this is the bass, middle and treble controls you may well have on your stereo. EQ is a fundamental effect applied to pretty much everything than can make up your song, then usually to the mix as a whole. I’ll start at the beginning with some basic scientific concepts you really need to understand if you’re going to get the best results from your equalization efforts.
The scientific term for pitch is ‘frequency’ and is measured in Hertz (Hz). This is one of the few scientific terms we have been blessed with when it comes to EQ, and so when describing sounds produced by different frequencies words like ‘boomy’, ‘woolly’, ‘fat’, ‘tinny and the like can crop up. In fact a mix I did in university was described to me by my lecturer as ‘a bit too doughnutty’, which left me baffled to say the least. Anyway, the range of human hearing is from about 50Hz to 20,000Hz (or 20kHz).
This spectrum can be divided into five sections when it comes to music equalization, which are as follows.
| 50-100Hz | ‘Bass’ ‘warmth’ ‘kick’ | Lowest frequencies are the most powerful, and can be a bit of a problem area unless addressed properly |
| 100-500Hz | ‘Low mids’ | These frequencies tend to sound a bit muddy and ‘woolly’, so careful mixing is again needed |
| 500-2kHz | ‘Middle’ | Most sound sources are in this range, human hearing is most sensitive to these frequencies, an they tend to be quite clear, and cut through the mix |
| 2k-5kz | ‘High Mids’ | Quite a ’sweet’ sounding range, with strong presence |
| 5kHz + | ‘Top end’ | Vibrant, tinny, high frequencies.Often described as giving ‘air’ to a sound source |
The basic idea of equalization is simple: you can change the loudness of different frequency areas in any given track or recording to change the character of the sound. You might, for example, boost the bass frequencies and cut the trebles for a warm, bassy (though possibly muddy) sound.
In the next post we’ll look at the different types of EQ.
Graeme Allen is the MD of Amati Studios, a company that works with some of the best mid-sized recording studios in the country.
In addition to his technical skills, Graeme is a first class musician in his own right, playing rock, blues and jazz guitar and classical violin. Visit his website at www.amatistudios.co.uk.
{ 3 trackbacks }
{ 0 comments… add one now }