Most mixing boards I've seen have a 12db per octave HP slope and a 18db LP slope, so that's what I usually use for guitars. For a kick drums, I high pass as steep as possible.
i use the waves q10 for hi low pass, but how do you set up and eq like this to the usual 12 , 18 db slopes??
I assume it is 18db cuz thats the minimun - maximun gain in the eq right?
one way would be to add your HP to 100hz, add a bell to 50 hz at -16db, but bypassed. Then you adjust the HP Q until the line on the graph hits the little dot of the bell
(or you could just adjust your Q value until you like how it sounds )