Anyone have Bookshelf speakers mounted over top of their subs??


Like the title says, I was wondering if many have done this to get a true stereo sound with dual subs, and bookshelf speakers?  My current set up is SVS ultra bookshelves, and 1 SVS sb2000 for now, adding another sub soon. I would like to build speaker stands to where the subs slide under the bookshelf speakers, and I haven't seen it done anywhere, just wondering if it is an idea worth pursuit?
musicjones
In terms of eliminating room effects, theory would say that asymmetric placement of two (or more) subs would have a better chance of being successful.  In practice, your patience, set-up skills, and EQ-ability would also be very important.
@auxinput,  I have already purchased batts of Roxul,  and some 1x3 select pine for the framing. Going to give that a go. 
Also, please excuse my ignorance here, but what does EQ stand for in this context . My thoughts are Equalizer, and Equipment, but I don't think I'm right. I have a lot to learn.
@musicjones - great!  Oh, another suggestion.  When you put together your panels, do NOT put a flat board on the backside (like a 1/4" plywood).  Any sort of flat board on the back will resonate and it will sound like a bad echo.  A 1x3 frame around the outside is just fine.
I was going to put a very thin cloth layer on the back side just to make a barrier between the insulation and my sheet rock walls . I do not know the correct term for it but I'm pretty sure the fabric store will have something along those lines