EQ (part 6)
- Cut off frequency: The frequency at which a high or low frequency EQ section starts to take effect. Also referred to as turnover frequency.
- Slope: The rate at which a high or low frequency EQ section reduces the level above or below the cut off frequency. Usually 6, 12, 18 or 24dB/octave.
- Pass band: The frequency range that is allowed through.
- Stop band: The frequency range that is attenuated.
- Filter: An EQ section of the following types:
- High pass filter: A filter section that reduces low frequencies.
- Low pass filter: A filter section that reduces high frequencies.
- Band pass filter: A filter section that reduces high and low frequencies.
- Notch filter: A filter that cuts out a very narrow range of frequencies.
- Gain: The amount of boost or cut applied by the equaliser.
- Q: How broad or narrow the range of frequencies that is affected.
- Sweep mid: A middle frequency EQ section with controls for frequency and gain.
- Parametric EQ: An EQ section with controls for frequency, gain and Q.
- Graphic EQ: An equaliser with a number of slide controls on octave or third octave frequency centres.
- Bell: An EQ with a peak in its response.
- Shelf: A high or low frequency EQ where the response extends from the set or selected frequency to the highest or lowest frequency in the audio range.
- HF: High frequencies
- LF: Low frequencies
- Mid: Midrange frequencies
- Treble: Hifi enthusiasts word for HF.
- EQ Off button: The sign of a good mixing console.
- If your mix sounds muddy, boost the main frequency range of each of the principal instruments. Boost decorative sounds even more and pull the faders right down.
- If you cant get your tracks to blend together in the mix, cut the main frequency range of the principal instruments.
- To make vocals stand out in the mix, boost at around 3kHz.
- For extra clarity, cut the bass of instruments which are not meant to be bass instruments.
- Adding EQ boost often adds noise. Listen carefully to arrive at the best compromise.
- Changing the EQ changes the level. Always consider adjusting the level after you EQ.
- If you add a lot of EQ boost, you may run into clipping and distortion. Reduce the channels gain to eliminate this.
- If you use EQ to reduce feedback in live work, take care not to take too much level out over too wide a range of important frequencies, particularly the vocal presence range around 3kHz.
- If you console has an EQ Off button, use it frequently to check that really are improving the sound.
When adjusting the amount of EQ to apply, the EQ gain in other words, its tempting to adjust it very carefully and change the setting in small increments. The problems with this method are a) that if the EQ setting isnt right then it is wrong and needs total reconsideration and b) that the ear quickly gets used to changes in the frequency balance of a sound. It may not always be appropriate, but its well worth a try next time you want to change the EQ level of a sound to grab the control firmly, twist it all the way up and all the way down and quickly settle on a new position which will hopefully be just right.