It's important to know that each note we play is not just one frequency, but countless other higher frequencies as well. If you are cutting instead of boosting, it looks just like the image above but upside-down, with a bell-shaped scoop. The higher the peak, the higher the signal level (amplitude) as you move away from the peak of the the bell (center frequency), you can see that other frequencies around it are also boosted, but to less and less of a degree as you move away from the center. Here is an illustration of one band of EQ boost, and how the range of frequencies affected by it increases and decreases as you adjust the bandwidth ('Q'): When you turn an EQ knob to a certain Hz number, or adjust the slider labeled with a certain Hz, that number is called the 'center' frequency because it's the center of a bell-shaped range of frequencies that get affected by that knob or slider- you aren't just turning up or down that one frequency, but also a lot of frequencies on either side of it. Low and High are two separate bands 80 Hz and 3000 Hz are usually in separate bands and if a single knob or set of controls adjusts a chosen frequency range, that is a band. A 'band' of EQ is a specific range of frequencies that has its own controls. Lower frequency = lower pitch, and frequency is measured in Hertz (Hz). Sound moves in waves, and the faster (more frequently) they repeat their up-down wave shape, the higher the pitch of the sound we hear. I'll try to clear some of that up here.įirst, we talk about 'highs' and 'lows', and those are broad terms that refer to the frequencies of our sound. The terminology is especially confusing- I see a lot of people misusing the term 'parametric EQ', for example. Even though most of us have used EQ controls for years, on a home stereo, car stereo, instrument, or amp, there's still a lot of mystery and misunderstanding out there about what a given EQ device or control actually does to your sound, and what the difference is between different EQ types.

3 band parametric eq