When you're choosing your speakers for 5.1 HT use using bookshelves as your rear surrounds, shouldn't all the drivers in the system be the same size? This is assuming they're all from the same line of speakers. Let me give you 2 examples of what I'm thinking about (I am doing this with other brands as well).... Matching: Swan Diva 2.1 6.5" (bookshelf) Swan Diva 5.1 6.5" (tower) Swan Diva C3 6.5" x2 (center) Not matching: Swan Diva 2.1 6.5" (bookshelf) Swan Diva 4.1 5.25" (tower) Swan Diva C3 6.5" x2 (center) It would seem that the first set would be more timberly matched than the second set. I know that since they're all the same line of speakers they should sound very similar anyway, but isn't the fist set a better match for eachother? or am I worrying about this too much?