Factory recommendations:

Acceptable:

0.4 - 0.95 cu ft net volume sealed

0.3 - 1.2 cu ft net volume vented, Fb = 22 - 36 Hz

Optimal Car:

0.65 cu ft net volume sealed

0.45 cu ft net volume vented, Fb = 27 Hz

I notice that the optimal vented box is smaller than the optimal sealed. I was thinking going sealed b/c of space issues but if going ported will really be smaller should I do this. Im also thinking aero ports and need some information on how to calculate what size I would need to tune to 27 hz. Does anyone own an rl-i if so what kind of box is it in?

Smaller until you add the port volume. You are going to need a hell of a long port that will require a funky configuration to do it. The sub will perform well in either type though. An Rlp 12" ported fits in a smaller box than the 10 once you add the port...

Smaller until you add the port volume. You are going to need a hell of a long port that will require a funky configuration to do it. The sub will perform well in either type though. An Rlp 12" ported fits in a smaller box than the 10 once you add the port...

yea thats why I was thinking about using an aero port but I have no experience with these

While you can go with a smaller diameter, it really won't solve the problem I described. For instance, my Rli8 in .64cuft (which would have a shorter port for the same tuning frequency than in a .45cuft box) is nearly 3.5cuft on the outside of the box to house the port. Porting a small enclosure is not a beginner maneuver in the world of audio.

Im def. not a noob to car audio but dont have the space to fit that box Looks like Im going sealed. Any recommendations on how big. Ill probably build two one to the manufactures optimal spec and one a lil bigger to try and get some more low end out of the sub

I think I replied in your other thread. Anyway, I say build one to optimal, then add stuffing as needed.