The car is a 2002 chrysler intrepid, and I have 37.5" X 14" X whatever depth I need. 3 Type R 10's, and I'm not sure about which way to fire them. The trunk is really isolated from the cabin. Even the old 6X9 holes are in the cabin not the trunk. So I'm not sure which way to fire them. Also not sure whether to go ported or sealed. They are in 3 seperate sealed enclosures as thats all I had at the time and the sound like they're missing something, they kinda fall off at some notes. Any input would be helpful. P.S. I've never built a ported enclosure before, so lengths and widths will be appreciated.

Cheers.

Alpine suggests the following:

Gross Volume: 1.3ft^3
Sq Area of port: 11in^2 (11"x1")
Port Length: 22in
Vent Displacement: .287ft^3
Driver Displacement: .050ft^3
Net Volume: 1ft^3
Dimensions: 12.5"H x 14.5"D x 17.25"W

I say build a box thats around 4-5ft^3 tune to the kind of music you listen to and go from there.

37.5"W x 14"H x 20"D (external)
36"W x 12.5"H x 18.5"D (internal) (4.818ft^3 Gross)

How do I tune?. Seriously I havent got a clue. I've never built a ported box before.

Your most pressing issue is how to get the subs to directly engage the cabin. Otherwise it will always sound like you are listening to the subs of the car parked next to you.

Great so what do you recommend

You'll have to use your imagination on that one. Is there any way at all you can get a sub to fire directly into the cabin?

Actually thats the way they're firing right now, but sound a bit "muddy". I'm going to build the new enclosure and am probably going to throw the new mrp-m2000 at them and see how things go from there.

turn them around, face the rear

try building the box directly in too the back seat. you could do this by fabricating a new back seat out af MDF and cut 3 holes in it for the subs then use a grill to pro tect your subs. you would need to build the actual box of of the MDF for the seat in to the trunk. then have it upholstered, you could probably use the old upholstery and have it port in to the trunk. this would give you a sweet looking set up with the subs firering into the interior of the car. don't ask me about the port tuning and dimentions of it the dimentions you will probably have to figure out your self. if you do use this design send me some pics. or post them.

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NOTHING BUT BASS

Well what I think I've decided is to do is follow Alpines recommendations. I will build three identical boxes then group them all together, which hopefully will act as extra support on the side walls of the box.
Each one will be 12.5"wideX14"tallX17.75"deep.
port will be 11"wideX1"tallX22"long.
which according to alpine should be tuned to 33hz.
Does this sound about right?