The LCR is a larger speaker physically and has an extra driver, but it is first and foremost a center channel - which is presumably part of the reason it is a sealed design rather than a ported design (centers too often end up in places with limited clearances, which is likely to get along poorly with speaker ports). Because it is sealed, it doesn't go as deep as the ported Bookshelf does (75Hz rather than 54Hz for the -3dB point). If I was looking for a speaker to use in a two-channel music system without a subwoofer, I'd look at the Bookshelf rather than the LCR. Toss a sub in the mix, of course, and things might change (although I still went with a pair of Bookshelves for my mains - the lower cost and smaller size helped justify the Bookshelves in my case).