Stupidly I bought an 18 Fi BL and didn't realize I couldn't fit the recommended box inside my trunk...its anywhere between 4-4.5 cubic ft..Is there anyway I can build a new box similar in size that will increase the current SPL levels and help not suffocate the sub-woofer so much?

You need to post the max dimmension of the area that you are willing to sacrifice for you enclosure. Don't forget about additional equipment either, they will also need space. Grab a measureing tape, and post your L H and W

You need to post the max dimmension of the area that you are willing to sacrifice for you enclosure. Don't forget about additional equipment either, they will also need space. Grab a measureing tape, and post your L H and W

31,18,22

Edited June 9, 201114 yr by KyleEbbert

Now you will have different ways to go about this, different choices, such as, sealed or ported, what type of wood, how thick of wood, any bracing, slot port or aero port, which way to face your sub and or port, etc etc. I would just wait until a box builder replies ok, because I'm no expert, but just to give you an general idea.

Sealed is not an option with that sub. You barely have enough room IF you use an external port. If an external port is not an option, I don't think you will have enough airspace for this sub as Fi recommends 5-10 cubes and you will have just a tad over 5 after double baffle, sub and bracing displacement.

BL's are for ported applications. Your probably going to need to use aero ports because they take up much less displacement than a regular slot port does. those dimensions alone with .75 wood will give you about 5.8 cuft. But thats not even with subs and aero displacements. You could always send it back and pay for a recone, and recone it to 15". That way you will have space.

Edited June 9, 201114 yr by Hzd Skizzy

Or sell it / trade and get a 15.

I bet a 15 in 4cu ported will sound much better than what you have now

Or sell it / trade and get a 15.

Ding, ding, ding. Winner.

Stefan's on his Charlie Sheen