my mark 4 sounds thin, help!!!

[TremoFan]

i just got my first mark IV this week, and i am totally in love with the cleans, but my lead channel just doesn't have the bottem end like i want. i've owned a dual rec solo head, a tremoverb 2x12 combo and still own a f-30 1x12. what can i do to get that bottem end like a dually? i have it sitting on a mesa 2x12 close back load with vintage 30's. my live cabinet is a lobo line 4x12 loaded with vintage 30's, it too is a closed back. also my mark is loaded with electro-harmonix tubes. i know this is the ultimate amp, but i cannot find a heavy setting that suits my music. HELP!!!!

one other note i really haven't been able to crank the volume on this thing yet. i haven't gotten up past 2 yet (this freakin thing is loud)

thanks guys