There isnt a Titanium Pro 10" or 12". Only made in 15" or 18". Eclipse Titaniums are all in the 9100 series, Pros having the "Pro" suffix at the end.
As for airspace, had good luck with 1.75 cubic to 2 cubic for a 10"; 3.25 cubic for a 12"; 5.5 cubic for a 15". Havent made any boxes for the Pro's just yet.
Eclipse says to only seal the Tis and ALums, but they both do very well, espically the Ti in ported, the Ti is not the most efficent sub but **** what a beast
There is a thread on termpro about the Ti's. They aren't meant to be sealed even though Eclipse markets them as a small sealed box sub.http://audioforum.termpro.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=8;t=020714