Enclosure Build For Alpine Type R 12" | 2005 Grand Prix

[Luda]

Im going to building an enclosure for my 12" type R to go in my 05 Grand Prix this upcoming week and ive got a couple questions.

The Enclosure is going to be roughly 5.5CUft with about 150SQin of port, tuned to 32hz. i have been out of the audio game for about 2 years, and this design is from about 2 years ago before the motor fell out of my maxima [last car i did subs in] so any input on how to improve it would be very much welcomed.

Now i have always installed my ported enclosures against the back seats, sub/port facing the rear of the vehicle.

But my grand prix has 40/60 split folding rear seats, i through a pair of shitty duals in that a buddy of mine had laying around to see if folding the seats down did anything to the sound. and it makes a noticable differnce in perceived volume [which i figured since the subs are moving the the air in the cab versus being sealed off in the trunk] after confirming this i got to thinking. i have been leaving the small [40%] part of the seats folded down when driving around, this got me thinking, what if i made the port the size of the seat so when its folded down all the air from the port is being blown directly into the cab. this got my gears drinding away and i came up with a couple more ideas. so let me know what you think.

Idea 1: Keep the above specs and do a traditional install.

Idea 2: Keep the above specs, but build the box with the sub facing the rear of the vehicle, and the port facing the back seats, so when i fold the 40% side down its blowing directly into the cab.

Idea 3: Same as idea 2, but enlarge the port to match to size of the 40% side of the back seat.

idea 4: use above specs, and have the sub behind the 60% side of the seat and the port behind the 40%

idea 5: same as idea 4, but again enlarging the port to the same size as the 40% side of the back seat.

with the sub facing one way and the port the other i am worried there might be some cancelation since your hearing the front and back wave at differnt times, but ive never seen any install like that so i dont know if its a valid concern or not.

any other criticism is very much welcome, as i said ive been out of the game so im a bit rusty on all this stuff.

oh and trunk space isnt a big concern, the trunk is pretty massive in my car.

****Edit****

the port will be a square port, fyi

Edited June 12, 2009 by Luda

[Guest]

5.5cuft for a single 12 is extremely huge. even for 2 12's its big

[Luda]

5.5cuft for a single 12 is extremely huge. even for 2 12's its big

it is fairly big but its giving me roughly 3db at the tuning freq[according to winISD], and ive got the space to do it

[Sp33dyG]

that enclosure is fucking huge for 1 12" but on the design i would seal it off from the trunk and have both seats folded down meaning

both subs and port firing into the car sealed off from the trunk

[Luda]

that enclosure is fucking huge for 1 12" but on the design i would seal it off from the trunk and have both seats folded down meaning

both subs and port firing into the car sealed off from the trunk

i am curious as to how to completly seal the trunk off from the cab, obviously making the face of the box the entire width/height of the opening, but would i need to go as far as throw weather stripping along the edge, or otherwise seal the edges?

and do you think its TO big?

[Nightshade]

It's time for a new box. That type r can get loud but not in the swimming pool that you have it in. New box with 1.8 cubes after displacement. Tune it with 2 4" aeroports to however long you want them for a certain frequency. If you tell me what freq I'll tell you how long to make them. That will increase your output quite a bit and save your sub from full x max. That will hurt your sub over a long period of time being in that large of an enclosure since the impedence rise is so low and it really has no cone controll.

[Luda]

It's time for a new box. That type r can get loud but not in the swimming pool that you have it in. New box with 1.8 cubes after displacement. Tune it with 2 4" aeroports to however long you want them for a certain frequency. If you tell me what freq I'll tell you how long to make them. That will increase your output quite a bit and save your sub from full x max. That will hurt your sub over a long period of time being in that large of an enclosure since the impedence rise is so low and it really has no cone controll.

i prefer square ports, theres just something that irks me about circular ports.

so that enclosure is to big then? i know the spec sheet says 1.7 but that seems kinda small, although my previous builds were 15's so i guess that could be why it seems small to me.

and the subwoofer isnt installed in anything at the moment, well i have it in a .75cuft sealed enclosure tapping into my 5.1 surround sound in my computer room but its not installed in the car.

Edited June 12, 2009 by Luda

[kfx450r]

..Sounds a little big..but just throwing it out there. I had a old style Type R 12" in a 7 cu ft ported box lol. It got pretty damn loud especially considering it was only on 100 watts..Nothing like my 15 now tho.

[Luda]

box is about 1/2 complete, stopped work after fucking up the port mounting [somehow got the front 7" wide and the back 6", said screw it and called it a night].

the box is roughly 3.2cuft after displacement, tuned to 35hz.

its going to be facing the back seats, sub and port, port being on the left side [40% split] since i ride with that side folded down. i am researching how to properly seal off the trunk, im thinking some sort of fiberglass shell, but i need more research.

[Guest]

your not gonna be able to run as much power to it in that big of an enclosure. just poppin in.