I have a f150 std cab and im about to do a blow threw ..

i only have room top to bottom for 12's but if i ever wanted to go bigger i have a idea how i could make it work.

I just have not seen many people or any one ever build a box like this.

Now t-lines work off of 1/4 wave and a 6th order is like a ported box with ports on both sides of the sub..

what would happin if i built a box and made it were there was port on the front and back of the sub like a 6th order but the ports were all 1/4 wave like a t-line just front and back....

the box would be huge because of the simple fact that each port would be around 9 feet long lol but hey i got a long bed truck so it dont matter.

Im not saying i will do this but i just wanted to know if any one has built something like this and if yes how did it sound.

The chambers of a 6-th order bandbass are tuned differently. You would have to tune the transmission lines differently too or else you get some serios cancellation.

Personally, I wouldn't waste the space with transmission lines.

I see what your idea, so that you could fit 15's or even 18's and they would be mounted in the bed area, behind the wall. I think if built right you could get some good SQ, but I'm not so sure you would get the larger output you are looking for. I would just say go with more powerful 12's lol. or you could do something like a 4th order, mount the sealed portion of the box and the woofers in the bed, then port it into the cab. that would be much more practical then crossing a t-line with a 6th order. I saw the setup done in the trunk of an older cutlass, it was ported through the rear deck, slammed quite nicely for a 2000 watt system and two 15's.