My first attempt at setting the EQ didn't go well (can't remember the frequencies I used) but my second attempt is much better. For reference, my amp is an Orange TH30 which has plenty bottom end already and I'm tuned to D standard. At the moment I have these settings:
Frequency 1 = 200Hz, 0 boost, Band Width of 1.2
Frequency 2 = 750Hz, 3 boost, Band Width of 1.6
Frequency 3 = 2.51KHz, 1 boost, Band Width of 1.2
Does that sound like it might be in the right ballpark? It's certainly an improvement on what it was.