EQing Common Sense

On just about every mixing console, digital audio workstation, or sound playback device, there's a function called EQ (short for equilization). This function allows the user to adjust specific frequencies along the sonic spectrum.

On consumer grade devices, these functions are either limited to general "low," "mid," or "high." Some of these devices have genre specific EQ that, generally, help to bring out desired nuances of specific types of music. For example, the EQ curve on urban music generally accentuates the lower frequencies and extreme high frequencies. On my car, my stereo has a "vocal" EQ setting that seems to boost the 1Khz frequency a few dB. I never use these genre specific settings, preferring to keep my EQ flat at all times.

In audio production, the EQ flood gates are wide open. On most mixing consoles, a user can dial in up to 7 different bands of EQ at varying widths. In computer based audio production suites (like Pro Tools) any number of plug-ins can be chained together to produce an nearly infinite combination of EQ. There is no limit to how much you can change a particular sound, for better or for worse.

For the beginner, if EQ adjustments are made haphazardly, these changes are usually for worse. Sure, a plug-in gives you seven bands of EQ to play with but how do you use it?

I consider myself still very much on the beginning side of understanding EQ, but there are a few things that I know now that I wish I knew when I was starting to mess around with EQ.

1. It's generally better to cut a frequency than to boost a frequency.
2. Different instruments have differing levels of information at different areas of the EQ graph. Notching out places in a mix for each instrument to live is a good approach to making a clear mix.
3. The voice has much of it's information at 1kHz.
4. Mixes can generally benefit from a high pass filter set to cut out everything below 50 Hz.
5. Boosting one frequency cuts another frequency. This sympathetic frequency will not show up on your EQ knob, so make sure you hear how one EQ adjustment affects the picture before making a second adjustment.
6. 1.5 kHz and the sibilant frequencies (5 - 8 kHz) are harsh. Notching those out may help a vocal. Cutting too much can also make a vocal dull and lispy.
7. Adding a little air (high shelf above 5 kHz) to a master buss can also help a mix. Too much of this can also ruin a good mix.
8. Acoustic guitars have a lot of information along the entire EQ spectrum. The style of music generally dictates how much to adjust these values. Also, the manner in which the guitar is engineered and the quality of the instrument dictates quite a bit more. Acoustic instruments are tough.
9. Bass guitars generate many different sounds. For most music a good relationship between the extreme low and lower mids is important when adjusting the bass. Bass is an area that I'm hoping to learn more about in the coming year. In general, my mixes can benefit from a slightly clearer bass presence.
10. A properly tuned kick drum can generate tones between 50 Hz and 80 Hz. It's a good idea to decide who's gonna be on the bottom, the kick or the bass. Then, dedicate a section of the mix to both instruments. You'll be groovin' much better then.
    

I could go on and on, but as sure as I make these statements, there really are no hard-fast rules. So much of audio production is mojo, or that which cannot be taught, explained, or even transmitted...it comes from pure instinct.

Happy recording.