Car graphic equalizers allow the listener to adjust the frequency of music. Frequency is the times per second that a signal switches to positive from negative and back to negative. The lower frequency is, the lower the speed of the signal will be and the clarity of music will be lower. Good frequency lets the listener have a more real feel of the music and its clarity in the car.
The car graphic face deck is a series of graph bars that show the speed and intensity of the frequency and signals. The graphic display helps a person without much audio or music experience to understand how the signals are differing and how changing one will affect the frequency and the listening quality.
The typical car stereo deck comes with a parametric equalizer system. That consists of two knobs can be turned to adjust frequencies with much greater control. The downfall is that without the display, a parametric equalizer is much harder to adjust than a car graphic face deck. It requires a more sensitive ear and an experienced person to measure the levels and be able to conceptualize how turning the sensitive knobs will directly affect the music.
For a person who loves music and appreciates quality but doesn’t have technical knowledge, a graphic equalizer is a much simpler way to improve sound through frequency adjustment. It’s also more efficient because once a graphic equalizer is installed, it can be preset for certain types of music. There will be a number of sample presets in the unit, so you can just pick one when you switch the genre of music you are listening to. Or it can be set with custom intensity and frequency for your preference. Then your custom setting is added to the preset ones and you can easily pick it when you know how you want to tweak the sound.