I've been fiddling with the EQ on the Empeg, and although I think I understand what the various settings are supposed to do, more often than not can I get the sound out of it I want.

Does anyone know of a program where you can put in many different EQ point; define Fq and Q and hey presto, see what the resulting curve would look like?

This would give a quick route on the Empeg to try out a couple of different curves to achieve a "target curve" (after having done an in-car measurement)