Audio Recording

Parametric Equalizer is one of the most useful mixing tools available to any audio/recording/mixing engineer. Yet, amateurs do not fully understand the concept and operation of these parametric equalizers. As a result, they misunderstood the usefulness of this tool and does not able to attain the sound quality they need.

Beginners in recording and mixing are often acquainted with only one equalizer which is called “Graphics Equalizer”.

While this is still an equalizer, it provides almost no use to mixing audio recording sessions. It is because of the following aspects:

a. Graphic equalizer cannot provide control Q (in applying EQ settings to a particular range of frequencies).
b. Some graphic equalizers are NOT designed for mixing and just for hi-fi equipment monitoring purposes.

So it means that the accuracy of the graphics equalizer will be in question. Now how to use the parametric equalizer? Before we illustrate the details, let us provide a good working definition of parametric equalizer.

Parametric equalizer is an audio frequency filtering tool that can let the engineer control the amplitude of certain range of frequencies. This control of amplitude can be done by boosting or cutting.

Below is a picture of parametric equalizer:

Since graphic equalizer only lets the user adjust the amplitude, parametric equalizer allows the engineer not only controls the amplitude but to a certain of frequencies as well.

The usual naming conventions used in parametric equalizer are stating the audio settings in terms of dB, center frequency Q. So for example:

Guitar (Left-Rhythm) = 3 KHz, Cut 6dB Q=1.4

It means that the engineer is adjusting the guitar left rhythm audio wave at 3000Hz and cutting 6dB with Q=1.4. Q states how wide or narrow are the cut (or boost if it is a boosting settings). In audio mixing, the most common Q settings are the following:

Q=3.0 ~ Q=4.0 (very narrow cutting/boosting).
Q=1.4 (standard cutting or boosting)
Q=1.0 (medium wide cutting or boosting)
Q=0.7(very wide cutting or boosting)

It is recommended that in any mixing sessions, you should stick with the above Q settings as extreme use of Q can severely affect the audio recorded signals.

Common applications:
In Boosting, I use a wider Q such as 1.0, and smaller amplitude (Q=1.0, 2dB Boost, 3 KHz), commonly used in boosting vocals, guitars, etc in their resonant frequencies.

In Cutting, I use a narrow Q such as 1.4 or 2.0 with higher cutting dB (Q=3.0, -6dB, 400Hz) for example in removing the cardboard sound of the kick drums.

Summary: The above settings are rough but standard guide in using parametric equalizer. Feel free to experiment with your own audio recording software in shaping the sound you need (of course this is the main function of parametric equalizer).