[quote author=Tiggity-T link=topic=35580.msg510606#msg510606 date=1134594383]
Well, I have basically that exact setup. My fronts are the Kappa 6.5 component and my rear are the kappa 5x7 2-way, powered by the 7541a amp. I have the stock HU with LOCs going to the amp.
Honestly, i do get a bit more bass response out of the 5x7s, which I found odd since I had read these forums and everyone said the round 6.5s are better for mid bass. And that's only when I have the sound set to a rear bias of R2. Unfortunately, even with the bass boost on the amp turned all the way up, our stock HU doesn't provide much in the way of bass, at least not from normal inputs. I have the auxmod, and when I play my MP3s through it, they have way more bass than the CD or Radio. Of course its EQ'd on the MP3 player.
I don't have a sub (yet), but its the best way to get the bass, and I dont think you'll notice any real difference between the 5x7 or the 6.5 for the rear speakers if you have a sub and the sound balanced. The 5x7 kappas were extremely easy to install, pluss you get to keep the water shield from the stock speakers.
As for 2-ways 3-way, my 2 way are very clear and crisp, I see no need for the 3-way.
[/quote]
6.5's ARE better for mid bass, as far as low bass response, 5x7's are probably better, at least will sound more full without a sub, but they sacrifice clarity for this IMO. If you want bass, get a sub, if you are unwilling to get a sub and want a somewhat full sound at the expense of clarity, get 5x7s. . .