The Sonic Studio website has a user manual which has information about the EQ.
I'm thrilled to own Amarra. I've created a default setting which works for most of my music, but there are times when I like adjusting for fun or to perfect the sound.
But sometines certain music requires more adjustment than normal, especially 80's pop which I find lacks bass. In that case I set the gain to 8.7, freq. to 100Hz and the Q to 1.0, which results in boosting the low frequency and presents a fuller, more complete sound. Without it, the pop music from that era sounds thin and tinny.
Increasing or decreasing the gain will result in the most dramatic effect, just be carefull because you can boost the bass gain too much. I don't ever set the gain higher than 9.0 on any frequency below 100Hz.
I hope this helps, I suggest listening to each of the pre-sets and finding the one you like best. From there you can add your own "touch" to get it the way you like.