You have not provided enough information to get a good response to your question. You haven't told us what kind of tone you are after, what settings you use now, what kind of bass you play, what kind of music you play, what cabs you use. Filling out your profile is very useful.
With all of that said I'll take a crack at it. You said that volume is an issue and that immidiately tells me that too much bass is being introduced into the EQ. If I were you I would take out the pedals, start with the EQ flat on your head, and possibly cut (not boost) frequencies no more than 3db. STAY FAR AWAY FROM THE SMILE EQ! This is a tone sucking mistake that too many bass players fall into. As a matter of fact if you are playing rock or metal you may want to go for more of a frown EQ (cut only). Mids are your friend and it's what defines your tone.
The truth of the matter is there are too many variables to offer a conclusive answer to your question. Even if you get it right with one rig and room it will be different if you change rooms, rigs, bass, or music style.
One last thing. If you are set on using the Sansamp with your head and boosting lows do it on one or the other, NOT BOTH.
Good luck and welcome to TB!