I would encourage you to mix the subs... room placement is more important than the type of sub... I currently have 4 subs playing in ~ 12,000 cu foot room, one in front right corner, two 20 feet back 1/3 and 2/3 across room bracketing the main seating sofa, and one on 2nd floor walkway across room. These drive the room modes ideally from these positions... might read the Harmon Kardon papers on multi subs, or the work by E. geddes on multi subs... pretty much confirmed what i noticed in the mid '90's when I started using more than one.quick question. is it "ok" to mix subwoofers? i had an HSU STF-2 <snip> in my room prior to building the shiva. for the last 6 months or so, the HSU has just sat in the corner of the basement. i considered moving it up to our living room, but i have the first sub i ever purchased up there from 11 years ago (jbl sub-10). i considered locating it in the movie room, but am wondering if this would be ideal.
OR
would i be better off getting another shiva (gen I or II) to match the current sub? not sure what to do at the moment...
John L.