First off let me apologize for some of the rambling. I'm looking for some of the experts to give me some advice on a box that I've been dreaming up in my head.

Ive been running some of my own calculations and trying to figure out if it is going to be possible to put 2 12's under the seat with no seat lift. The subs I've picked out need.8 Cu Ft of space per sub. Mounting Depth is 2.5 inches. Sub itself takes up .05 Cu Ft of space. Personally I'm not to worried about that if i get the box built with .70 Cu Ft ill just stuff it and bring it up to .77 I personally don't think a person can tell the difference between .03 but that's a personal opinion.

Now my basic box size i came up with dimensions from some other designs I've seen out there. I figured out a box that is 52x15x5 Obviously height could be a little more like 6 1/2 sloping down to 4 3/4 but since i only need basically 3 inches mounting depth i figured 5 would be perfect and would only require a small slant front to back. This would also allow for the box to be placed up on legs to allow more room for the sub in the downfire position.

Now assuming the box is made out of 5/8 MDF some fast calculations to give me a basic internal airspace 50.75x12.75x3.75 would give internal airspace of 1.4 or .7 per sub. I can live with that as i said with stuffing. Then unfortunately you run into the good ole cutout for the seat and compensation for the hump. If my calculations are correct the cutout takes away .03 Cu Ft and the hump would remove roughly .05 so .08 takes me down to .62 sub takes out .05 which would drop me to .57 stuffing it would take me back up to roughly .7 leave me .1 off. I'm thinking with my calculations I've left enough room to make the box larger in a few places to gain that extra airspace.

Am i way off with these figures? I'm just looking for a good way to get 2 12's under the seat with no need to raise the seat. It seems to me with a custom box it could be done no problem.

I should also say i don't know much about airspace other then its the internal dimensions of the box. I do know in some enclosures the shape of the box makes a difference. In a sealed box i honestly don't know. Will i have issues with the odd shape of the box where the seat cutout is located or is this not an issue in a sealed enclosure. Also i know i left out the 5/8 divider between the enclosures i figured that would be minuscule enough to not make a big difference in just some outside calculations before i give the box its actual design.

 

Ok.... Umm what drivers are you running. And Im not sure what you are looking for. Do you just want me to go back through and edit everything?

 

JL 13TW5's Im basically just looking to see if my calculations are correct and if this is actually possible. I may go with the RE SL12's also but for now the JL's are my goal. Money for the drivers isn't an issue so im not worried about that part of it.

Input from someone like you would be great i haven't been active in the stereo world for 12 years now and saying im rusty is an understatement.

Basically my goal is this - Run the 2 JL 13TW5's in a box with airspace for the drivers(.8) and not have to use a kit to raise my seat. Id also prefer to have 1.5 inches of space between the driver and the floor of the truck to allow the driver to throw all it wants without hitting the floor.

 

1.5" isnt necessary. 1.25" at worst.

Run a search on here for Arcuhtek's box dimensions. That will help a lot, I think. And with those drivers 3/4"MDF is a minimum.

 

BM > everything you are considering. .5 cubes = pwnage.

 

Thanks i pulled his dimensions those will help me quite a bit. Also thanks for the MDF tip cause i wouldnt have thought twice and just built it out of 5/8's

 

I looked at the SI BM's and they were a definite choice. I talked to a few friends that are still into stereos quite a bit and they all told me the JL is still hands down the best shallow mount out. Then i was told either the SI or the RE came after that. I figure i would go with the JL's if that isnt going to work ill try one of the other 2.

It very well could end up being the SI especially because of the airspace.

 

I'm a firm believer of "dont knock it until you've tried it." In my personal experience, JL isnt in the same league as SI, not even close. ESPECIALLY when you factor in performance vs. price. (ironic that i currently have 2 JL subs in my truck :o).

Now with that said, the BMs aren't even out yet. But i have played around with a SI Mag v4, and it is no doubt the best subwoofer I've heard.

 

Exile, JL, SI.

 

Ill contest to Si being better than JL. I recently had 2 jl 10 w3v2 subs in the truck. Those blew a while back after like 3 years of use and then I couldnt figure out what to do. I then purchased the new si mags. Built my own box with plexi window and I think that the sound from the si mag is gobbs better than the w3v2 was. Also i only paid 50 bucks more per driver.

I know people are reluctant to purchase subs they havent heard before but I will vouch for a Stereo Integrity over jl any day.

 

what does he meen by stuffing the box

 

What stuffing means is filling a box with a product called polyfill (can be picked up at walmart for like 2 bucks). People say this makes the subs think there in a bigger box. In reality it deals with the density of the material and how they slow down the sound waves coming from a sub box. This then makes the box seem larger because of the slower soundwaves.