A parametric equalizer (EQ) is like a sculptor's tool for shaping sound. Just as a sculptor uses different tools to shape a block of wood into a specific form, a parametric EQ allows a record producer or a sound engineer to adjust specific frequencies of an instrument in order to shape it into the desired sonic form.
The "parameters" of a parametric EQ refer to the specific knobs that can be tweaked and the amount of adjustment that can be made to each center frequency. This allows for precise control over the final sound, allowing the engineer to create a wide range of effects e.g., the telephone effect. The three main controls of an EQ are frequency (f), gain (g), and quality factor (Q).
In general, a shelving filter is good for making broad changes to the overall tonal balance of an instrument, a mix, or a podcast, while a bell filter is better for both making more precise subtractive adjustments to a specific range of frequencies and making tonal changes if you use a broad quality factor e.g., 4 or 3 ⅔ octaves.
The "parameters" of a parametric EQ refer to the specific knobs that can be tweaked and the amount of adjustment that can be made to each center frequency. This allows for precise control over the final sound, allowing the engineer to create a wide range of effects e.g., the telephone effect. The three main controls of an EQ are frequency (f), gain (g), and quality factor (Q).
What is the quality factor parameter?
Q factor determines the size in width of the boost or cuts applied to a particular frequency. A high Q factor (e.g., 4) means that the boost or cut will be applied to a narrow range of frequencies around the center frequency, while a low Q factor (e.g., 0.4) means that the boost or cut will be applied over a broader range of frequencies.Gain
This allows you to add or subtract audio material around the center frequency. For mastering music, you don't need much gain for the most part e.g., 1, 1.5 dB, or 2 dB is more than enough. Thus, many audio software plug-ins for mastering usually default to 3 dB or 6 dB for the display range. But for sound design and sound engineering, the sky is the limit.Frequency
This lets you select the center frequency for the boost or cut you want to make.Bell or shelf?
A high or low-shelf filter boosts or attenuates frequencies above or below a certain cutoff frequency, while a bell filter boosts or attenuates frequencies around the cutoff frequency and then tapers off towards the higher and lower frequencies of the curve meaning sounds that are closer to the edge of the curve are less affected.In general, a shelving filter is good for making broad changes to the overall tonal balance of an instrument, a mix, or a podcast, while a bell filter is better for both making more precise subtractive adjustments to a specific range of frequencies and making tonal changes if you use a broad quality factor e.g., 4 or 3 ⅔ octaves.
