Ive been thinking about building a box for the home theater. my tv is about 48" wide, and at the back, its about 40" wide, but it is only about 16" deep, so theres lots of room behind it in the corner and I was going to build a triangular box to fill the empty space.

I already have a old RF stage 1 12. I see the Fs and VAS specs used alot for HT and this subs Fs isnt too high at 27 and the suspension must be somewhat loose at 80L equivalence, not real high, but better than most subs Ive come across.

rest of the specs can be found here. http://www.rockfordfosgate.com/scripts/rightnow.cfg/php.exe/enduser/fattach_get.php?p_sid=FtNpc2Kj&p_tbl=9&p_id=273&p_created=1083013966

its just going to be powered off of our theater in a box receiver for now, which only puts out 115W, but the sub is a 3 ohm sub, the fosgates a 4 ohm sub, bummer...

if I were to build a large low tuned box for the fosgate off ~85 watts, should it be louder/lower than the stock 6.5" driver off of 115 watts?

I will probably take the sub out from behind the tv and get a better idea, but Id say from just looking and shining a light down the port its only about .3 cubes net tuned somewhere in the high 40's.... could be way off though.

I was thinking of something around 5+ tuned to around 18-20? not sure why so big, I just always see HT boxes are big...

You could build a Tline tuned to 27 or 29 hz, and it will play down to 20 hz without a problem.

And it will be very accurate to play music and watch movies, way more efficient then a ported box, so it would deffinetly be much louder then the 6.5 inch driver.

I would go with a low tuned ported enclosure

With that little power you can make the enclosure a little on the large side to improve efficiency.

what would you say is a little on the large side? 5-6? or bigger? and Ill have to do some research on a T line

I could have the math slightly off, mostly because Im not exactly sure on how you calculate a flared port (goes from about 2-3/16 to 2" within about 1/8 inch inside the box, and then goes from 2 to maybe 1-5/8 in 3 inches, then back out to 2 in 1-3/8, and then to 2-1/2 in the last 1/4 inch)

I just made it simple since I dont need to know exactly and figured it as a 2" straight port. (I know how to do the math for all that, the part I dont know is how it all affects tuning)

anyways, it is .3186 @ 62.2.

Im designing the box for the 12 right now, if I get it figured Ill post it up.

does the same 12-16 in^2 port area per cube still apply in HT? just seems weird cuz I dont ever think Ive seen a HT box with a 112 In^2 port.