Hi DarryAG,
I am Dave, I will help you with this.
On a graphic equalizer, those sliders are for adjusting the different parts of the sound, for bass, that would be the sliders to the left, and for treble, the sliders on the right, and the middle ones are for sounds like voices.
So for example to increase bass, move the two left sliders upwards.
It is best with an Equalizer to use one of the presets, find the preset that sounds best for you, then adjust each slider slowly to try to improve your sound.