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?
It seems logical to me, but I am a bit of an audiophile novice and this is my first real setup. I'm glad someone has gotten good results,  I cant see much of a difference between this and if I had tower/floor speakers, other than the subs will get much lower end response than any tower/floor speakers I could afford. 
Hey Music,

True, but you are missing one important feature. Subs can be placed in acoustically ideal situations, which may NOT be under the monitors.

Sub placement, bass traps and EQ are all critically important in getting good sound out of them. Subs have to integrate to the main speakers as well as to the room.

Do this right and it’s breathtaking.

I would rather have 1 sub well integrated than 2 poorly set up.


I do not disagree,  I have a room treatment ordered, and I am going to build some bass traps myself, or GIK is a local business to me, so I can pick some up there. Right now the one sub I have is sitting midwall and my room is not ideal, so there are some nulls and some boominess. Hopefully the treatments and traps will control the not sure how they affect the nulls though.
Unless you're using room correction, this almost certainly a bad idea.  I'd always place the subs for smoothest bass and the mains for best imaging.  If you just make sure that you're crossing low enough from sub to main to eliminate subwoofer directionality, you won't be trading away anything (except appearances) with asymmetrical placement.
I have the sub set at 80hz so directionality isn't too much of my concern, it's more of filling in the nulls, and having better overall sound. I may try facing the 2nd sub directly at the 1st sub on the opposite wall. My room is 11x19 (sub on the 19 foot wall) but there is a stairwell, and a 5 foot entryway to the kitchen,  so sound waves are escaping like a death row inmate. Plus i have wooden sub floors. Not a great scenario, but it's what I'm working with.