So I'm thinking about changing the back speakers. The new receiver has really improved the sound, but the midrange speakers in the back just sound awful. I heard that the speakers in the back need special adapter plates, has anyone replaced them ... I've got a chance to get a really good deal on Infinity Reference Series 412i 4 inch, 2 way speakers, but I'm wondering whether that's a good/bad speaker for the ti ... any advice would be greatly appreciated ...

Oh yeah, has anyone heard of the powered subwoofer Infinity has, I guess it's comparable to the Bazooka tubes ... 10" sub w/basslink ... I'm thinking about getting that, it looks like it could fit really well in the ti's trunk.