Bookshelf speakers on actual bookshelves?

I have to put my Mani 2's on actual built in bookshelves (sp?) which are also tied to a set of drawers. The wood built in has many hollow spaces and is large enough to wrap around a corner. I am fearful that the Mani2's bass response will either vibrate or deteriorate. Does anyone have experience with what to put under the mani 2-or similar bookshelf-to minimize the problem and maximize the sound? (This speaker is a two way with a port in the back. Electronics will be of high quality.) Thanks in advance.