Yeah JL calls for the box on the box being 2 cubic feet (55litres)...
... A quick model of a JL 15 calls for a 2 cube box that will make port placement easier.
I am modeling it as a bandpass with a left side box as my trunk space. As far as ports, is dual 4" a replacement for single 8"? There's no way I'll be able to bend a 6" or 8" port to curve around my gas tank.I think you will likely be going towards a 6 or 8" port.
(It depends on the manifold to deck distance, and tuning freq... which is probably ~40-70 Hz?)
I am not saying that any of what I mentioned is overly factually... it is just ideas to get someone else to opine on it.
Yeah JL calls for the box on the box being 2 cubic feet (55litres)
That is the box on the left, and in you case it is 1000 litres.
I think that you will need to model it as a bandpass, or an IB?
Just any old sub may not be optimal in this situation.
Maybe you could model it as a T-line if the snorkel is long?