ok i have my box layed out pretty much.. just a few concerns left.. its for a 15" type r. the older one, alpine didnt list any ported box ranges to stay in volume wise, but the sealed box volume range is 1.3 - 2.5 cu ft.. the one i have designed is 3.79 after sub and vent displacement anyone think this might be to big?.. also it is tuned to 34 hz.. is this to high for a 15?? just to give me perspective does anyone know the frequencies played in late night tip??
I'd go more like 3 to 3.5cu ft, port tuned to 28Hz (6" ID port or slot vent)
they recommend sealed because the Qts is .48.. that's just below the cutoff for going sealed box.. it'll work ported, but it's more inclined to a sealed box due to suspension and damping factors of the driver.
hmm.. im using this moreso for spl than sq for this sub.. since i already have an sql setup... the way i have it designed right now alows me to have an unbent port which is (15" x 2.5") 17" long btw with the port facing out the back towards the front of the car and the sub facing the back... on one hand i dont want the sub to bottom out ( as it did when a made a 4.somethin sealed box) but on the other i want to get as much spl out of it as a can.. and having an unbent port so i have herd helps out.. and i dont think the dimensions will fit the car properly if i want to keep the rear port design while shrinking the box
If you want SPL for a 15" sub, really you're going to look at 4 cu ft net and a tuning around 35hz. Any smaller in box size will limit the sub's SPL capabilities. Glasswolfs recommendation above would be great for SQL.