In terms of what? The pair of 6.5's will have a little more cone area than a single 8 but likely won't be able to play as low. Unless it is due to space constraints, I would stick with a single 8 (ported if you can). There are quite a few choices out there. What kind of car is this going in and what is your goal?
"A man is a success if he gets up in the morning and gets to bed at night, and in between he does what he wants to do." - Bob Dylan
It seems like you would have to hack up your door panels more to fit 2 6.5's than you would to fit one 8". Unless I'm missing something. What car are you working on here?
"A man is a success if he gets up in the morning and gets to bed at night, and in between he does what he wants to do." - Bob Dylan
Looks much better (and I'm sure sounds) better than the stock grill. There are guys with the deeper 8W1 driver in.
IMO, you should just make some spacers and go for it because the ZR800's are really nice midbass drivers...then put some 5 1/4" or 4" up top for midrange. Would go that route over a 6 in the bottom and a 6 at the top...would be a shame to take out an OEM 8" and put in a 6"!
I went with 6.5s in my S197 mustang because I couldn't stand the thought of extending the speakers out much past the 3/8" that I did. The Mach5 Audio MLI-65s served me well.
2012 Subaru WRX - JL Audio C5-650s run active off a Lunar L450; Digital Designs 1508 powered by a Lunar L1500; Pioneer DEH-80PRS as the source unit.