Moving into a larger enclosure

I just got all the parts for an Acoustic Energy AE 109, Crossovers, dual 4.5 "woofers" and tweeters. Port tuning is 45hz. I do not have TS parameter on all the drivers. The original enclosure is around 0.85 cubic feet, Port tuning is 45hz. Planning to move them to a 1.5 cubic feet enclosure. Should I retain the 45hz tuning or can I go lower?
 
A larger box volume can be exploited in many ways. Often it leans toward a reduced bass level, and sometimes toward a lower cutoff. With a ported box you have one more degree of control, but if you try to get more out of a box that's too large you can put a kink in the response which may not sound as good. On the other hand you could use a different kind of resonant enclosure, like a transmission line.

A benefit I can see would be a larger frontage on the outside of the box.