View Full Version : Truck Box Mounting Depth Question

11-10-2008, 01:31 PM
Ok guys this may seem like a dumb question but how do you guys figure what your mounting depth will be when you are building a truck box?

I mean, If the sub has a 6.5" mounting depth, how do you know if you have enough depth for the sub to fit based on your top depth and bottom depth of the box?

Am thinking about running some FI Q's in my regular cab truck as they dont need alot of airspace. The sub has a 6.5" mounting depth. I was going to make the box 24" tall and not sure what I would need as a TD and BD to make the sub fit.

Any help?

11-10-2008, 01:49 PM
geometry FTW

ok edit: it sorta depends on the woofer. The mounting depth is directly back from the middle and most subs aren't that deep around the entire back...so you either have to sit down and do some math or just ad an inch or two to your length. Or just make the box rectangular and be done with it :)

11-10-2008, 01:51 PM
Do you happen to know your maximum top and bottom dimensions?

I usually go the easiest way I have, draft it up in cad and measure it there. You could always draw it to scale on a sheet of paper and do that. Also much of it depends on how low in the box the sub can go, you get more mounting depth with the sub nearly on the bottom of the box versus the more cosmetic look with the sub in the middle of the face.

11-10-2008, 02:07 PM
This appears like it would work. Not sure if your going with 10's or 12's. Just checked the FI site and looks like your thinking 10's since the 12's have a mounting depth of 7" Either way it will still work roughly the way this drawing shows. Just add a little more and ya should be good.


This only leaves 1/8" between the motor and the backwall, and 1-3/16" from the center of the motor (pole vent) to the back wall. Not sure how much length ya wanna go with but the cross sectional area of that box would be 112.27 in^2

11-10-2008, 02:10 PM
That box looks pretty good, just make sure the pole vent clearance is enough.

11-10-2008, 02:16 PM
yea I think I would personally give it another 1/2" to an 1" on the bottom to give it some more room, but also if he goes with a 10" and drops it a bit lower it should be good. Probably leave plenty of room to throw the amp up in the middle of the box too.

11-10-2008, 02:34 PM
Dang, I always forget to add some type of info lol.

The Q's are 10" like you though.

Jdc753- my max dims are pretty much just as you listed. I believe 9.25" or so on the bottom and 4" on top. I was going to put the sub as low as possible to the bottom of the box.

That diagram helps alot. I am a visual person. Thanks!

Just for a ref, I am going with two boxes (one behind each seat) dims are 24"h x 12"w x 4"TD x 9.25 BD. Those dims will be adjusted to the airspace I would need.

In between each box am going to mount my amps.

11-10-2008, 02:37 PM
sounds like a good plan for sure.

Heck ya could even go ported with that volume. 0.7 before displacement per box. I don't know too much about porting but a 3" aero in the box or out the side near the top might work pretty good too.

11-10-2008, 02:44 PM
I would like to try it sometime, but I dont know to much about porting.

11-10-2008, 02:47 PM
geometry FTW

i **** at math. i dont know **** about geometry. I think algerbra is as far as I got. :crazy:

I wouldn't even know what formula to start with to figure this out.

12-01-2008, 09:54 PM
Dito ^^^ will this sub work if I have 7.5" of mounting depth, about 60" length, and 23" high..... http://www.handkaudio.com/product.aspx?ID=121 or this one http://www.handkaudio.com/product.aspx?ID=121 Or do you think a shallow mount sub would be a better setup for me ( I only want 1 sub )