Hmmm, I was about to mention all the f hole tricks I know but if your axe is a painted f hole model than that wont be much use!
Have you tried raising your amp off the floor and not letting the sound from the amp hit the back of the guitar? I had an es330 and I could stand right in front of the amp or it howled like a mofo. Just moving it a bit and standing to the side made a big difference. I played pretty clean back then though so didn't have much drive in the signal.
Let me know how you get on! Oh, and a photo of your axe would be nice