Keep in mind that I have not used Martin's worksheets to actually produce anything (just to check some things I already have...so take this with a grain of salt)
When I run the TL you have with the Dayton RS270 ($63.50 at PE) and .2lbs/cuft stuffing I get:
about 10db down at 23-24hz
4db down at 30 hz
Flat from 40hz to 80hz
There is a suckout above this but since you aim to use it as a sub...no problem right
When I run the TL you have with the Peerless 850146 ($69.96 at PE) and slightly more stuffing (circa .25lb/cuft) I get ver similar results. flat between 80 and 40 with a slightly earlier but shallower roll off.
about 10db down at 22hz
4db down at 30hz
1db down at 40hz
When I run the TL you have with the Seas 25F-EW ($65.80 at Madisound) and similar stuffing I see
about 10db down at 24hz
5db down at 30hz
about 3db down at 40hz
I stuffed all of these lightly because you suggested use as a sub (I.e suckouts above 80hz wouldn be a problem) and you expressed a need for efficiency. All of these drivers seem to "work" in your TL, with the seas probably the least successful.
Tests performed at
http://206.13.113.199/ncdiyaudio/mark/Testing/Woofer3/10 inch woofer test.htm
tend to suggest good performance for the Dayton.
The peerless has a much larger xmax spec than the Seas (9mm to 4mm) with the dayton in the middle at 6.6. How accurate these numbers are is probably debatable.
Sean
to start with the 2 that come to mind are: the peerless 850146, and the vifa m26wr-09-08 they both have qts around .32 so they would be ideal with nice smooth responses, allowing for simple x/overs and possibly two way with the right tweeters of the 2 l would say the peerless is the cheaper