newbie level question/volume differences

i tried to do my research on setting up presets and one thing eludes me and i guess im asking if there is a parameter i've missed or someplace im not looking. so im scroll thru rig master and load a profile, bam really loud, i check the amp level 0db, volume at 0 ( main outsat -12db using line out to sound board, i do find this gives me alot more headroom, the xlr outs are hot) next patch 2/3 rds the volume and all the volume settings are the same. there are no boosts,eqs, anyting eslse in the chain and if there is i turn them off

where is the cab volume parameter? i get tone shift and character but can't find anything else.