You could get a larger sub and still split it, use the small one maybe in the back of the room and large in front, it may give you more dynamic slam, do you have the sub in the corner (where it works best?)
I would look into getting a more powerful 12 inch sub say 200 watts atleast..it may be enough that you will no longer need the lil sub, I have mine next to my listening position and love the results...maybe put yours back there to try and see if you will like it enough to not spend any money. I have a HSU Research sub and like it alot, also I have had Definitive tech and liked it also, If you love music make sure you get a sealed sub with no port, those are the tightest in bass response...if you need big boom for movies....your options are wide open!
I would look into getting a more powerful 12 inch sub say 200 watts atleast..it may be enough that you will no longer need the lil sub, I have mine next to my listening position and love the results...maybe put yours back there to try and see if you will like it enough to not spend any money. I have a HSU Research sub and like it alot, also I have had Definitive tech and liked it also, If you love music make sure you get a sealed sub with no port, those are the tightest in bass response...if you need big boom for movies....your options are wide open!