Not sure where to post this so feel free to move if needed
i have a buddy that wants me to build a box for a 1 fi btl 18. he ordered the spl one even tho he wants to play music on it i told him he should send it back and get the right one but he said build the box so i am. so my question is what is the recommended box size port size and port length fot this sub. space is not a problem it will be in the back of a ex cab chevy truck the back seat has been taken out. thanks for all the help
The BTL will play music, no worries. The BL or Q may have been a better option but just dealing with shipping a BTL back would convince me to keep it too.
Fi recommends a pretty broad range for that sub, from 5 cubes to 10 cubes. Tuning will depend on your desired use and/or your car's peak frequency. I'd recommend somewhere between 14 and 16 square inches of port area per cubic foot of net internal enclosure volume, the length will obviously be determined by your desired tuning.
If I was you I would send it back. The gap on the SPL version is really tight and you will get alot of coil rub and mechanical noise running it on music. I have My BTL in 7.5 ft3 tuned to 30hz with 120sqin's of port and it kills the lows. Tried alot of other combinations of box size a tuning and I like this one the best.