First build, Need advice

[Aeisuhr]

Ok, starting off this is the first time iv attempted to build my own ported box, its going in a 99 mustang full backseat box(almost a wall) but dont really want to build the wall as its a bit past my ability level, i just want a box that takes up the whole seat.

First im going to get all the info i can out of the way XD

My available space to easily work with is 38Wx28Hx18D because im a fairly tall person and so is the people that would ride with me 18 is as deep as i can go.

Alright that out of the way i already have a 220 amp alt, 2 audiopipe apcl 15001D amps strapped. watched a dyno vid and assume these are about 1200. so guessing about 2400 together at 2ohms. a XS Power D975 battery in back and a yellowtop optima in front. and 4 alpine type R 12 4ohm dvc.

As of right now they are in two prefab boxes basicly stacked on top of each other and 2 things are wrong 1 it sounds horrible no low bass and its not loud! I literally have 2 in a slightly bigger prefab box in my daily driver car that sounds louder than these! Same subs but with a rockville m4 almost same output as the two mentioned above. but the boxes the 4 new ones are in are attrend bbox its right at 1cf after sub displacement. and assuming thats where both my spl and low end are dieing. (tell me if its that or something else)

How much would i gain by building a custom ported box, attrend says their bbox is tuned to 39 not sure if thats accurate but the fact that these 4 are quieter then the 2 in my saturn trunk im very dissapointed. Both setups are ran on 0gague ofc. i honestly dont know if its the box, car, amps, or the fact that the saturns alpines are the style before but both have same rms ratings.

These were not set up with a oscope or distortion tester i ran a 40hz track at where my headunit distorts and used a dmm to get to the voltage that the dyno for this amp says it started to clip and turned it back a bit, i know its not exact but it should be close enough to give me better results than i have.

Any help would be appriciated. Just start throwing stuff at me ill check back often Thanks in advance!

[Guest]

no low bass and sounds like shit because you have the prefab boxes on your backseat. i think it has something to do with the backwave.

[Aeisuhr]

off the seats or poor box design?

[RainStryke]

You do not have enough space to run four 12" Alpine Type R's.

Your subs have a minimum recommended 1.38FT³ net space per sub, that's over 5.5FT³ of net space needed and you only have 4.6FT³ and that's gross space, not net. Seems like you should be running no more than 3 of those 12's with the space you have. I would actually suggest a properly built box and only 2 of those 12's with the space you have, because 3 would still be cutting it close.

If you don't have the tools or means to build a box, I'd suggest looking into something like this:

http://www.ebay.com/itm/Alpine-SWR12-Hand-Crafted-Birch-Ported-Dual-Subwoofer-Enclosure-/282036739039?hash=item41aab31bdf:g:IAAAAOSw1KxXNcCD

That guy builds those boxes, so he can make adjustments to it to fit the measurements you have.

[n8ball2013]

Please read a lot. Your idea is not very sound.

[Aeisuhr]

Please read a lot. Your idea is not very sound.

not entirely sure what you meant by this

[Aeisuhr]

You do not have enough space to run four 12" Alpine Type R's.

Your subs have a minimum recommended 1.38FT³ net space per sub, that's over 5.5FT³ of net space needed and you only have 4.6FT³ and that's gross space, not net. Seems like you should be running no more than 3 of those 12's with the space you have. I would actually suggest a properly built box and only 2 of those 12's with the space you have, because 3 would still be cutting it close.

If you don't have the tools or means to build a box, I'd suggest looking into something like this:

http://www.ebay.com/itm/Alpine-SWR12-Hand-Crafted-Birch-Ported-Dual-Subwoofer-Enclosure-/282036739039?hash=item41aab31bdf:g:IAAAAOSw1KxXNcCD

That guy builds those boxes, so he can make adjustments to it to fit the measurements you have.

with the messurements i gave how are you getting 4.6 i got 9.3Ft and assumed taking displacement and bracing i shuold have plenty

[ShadeTreeMechanic]

Two subs in the right box will be louder than four in the wrong box. Use the search function to see what the other mustang owners are doing to get loud.

[Aeisuhr]

Two subs in the right box will be louder than four in the wrong box. Use the search function to see what the other mustang owners are doing to get loud.

I'll do that, just thought with a possible 9cf to work with since i already had 4 and 2 amps to push them, seeing if that space would work to get all 4 to sound good, with the suggestions of everyone on here.

[Wasteland_Audio]

are you going to be setting this box directly onto the seat cushion? if so i would take the bottom and back of the rear seat completely out and then re-measure. i bet you would have enough room if you did that.