Well, I like alot of those lows, so I'm thinking the cab just isn't hanging lol as for lowering the gain and increasing the master.... tried it. Still will have a point of break up.
hmm...it doesn't look like you're over eq'ing but, with the LF engaged, you are running quite a bit of low end.
Two things-
* This is possibly a cabinet issue.
* Have you tried lowering the gain and increasing the master?