Case of the dissapearing Bass

This might sound odd but....

My bass is gone, when i say gone i mean really really gone. I moved my speakers around the room to try to take some of the drone out of the bass. ( moved the speakers further off the wall etc)After having a play around I managed to tidy up the drone a little too well. Now i have no bass.

I have a pair of B&W 802d's, The woofers are popping away like mad im really giving the speakers a workout and Ive totally killed the nice bass slam I had before now to the stage where its non exitent unless I get behind the speakers.

I would have thought the maybe they're out of phase but i havent changed the leads or anything so i dont see how that can be the case.

Im at a bit of a loss. I dont know what to do to get my bass back. Ive even pushed the speakers back closer to the wall than I had them before to no avail.

Any thoughts?