Anyone know stuff about graphic equalisers? How to get best sound and what each slider is for as deeper etc?

Answer 1

Yes, why?

Answer 2

Use the presets to start with, try a few and see the difference on the same piece of music.
Then try fiddling, one slider at a time; you'll soon realise that the presets usually do a better job but you can tweak them.

Answer 3

Sliders to the right are for high frequencies as you go toward the left you go lower and lower. About mid way vocals come into play, around 63Hz you can add a bit of punch to your bass.