Box Design Help? EDIT: Done. Pic Added.

[2007TBSS]

Sup guys. Wondered if I could get a little help with a sub enclosure. I got 2 RE SEX12's that will be powered by 300RMS per sub via XTANT amps. My goal is to leave some space for luggage and such in the back of the Trailblazer, so I was considering using the width and length available and keeping the height to a minimum and firing the subs up. Then adding a cover piece of 3/4" and doing some custom aluminum covers for the speakers to keep them from being damaged.(I'm a machinist) I am assuming sealed would be best since I'm not running an insane amount of power to the subs. I'm not looking to compete or have insane amounts of body flex, just a good clean sound for all kinds of music. It would be nice to get a compromise of some low drops and nice tight sounds as well, if that is possible.

I'm pretty good with my hands and have access to tools so I would be willing to try about any kind of design within reason.

Thanks for your help!

Here's the specs for the subs.

Recommended Enclosure Specifications

Recommended Enclosure Type Ported / Vented

Sealed

Minimum Sealed Box Volume 0.75 cubic feet

Maximum Sealed Box Volume 1.0 cubic feet

Minimum Ported Box Volume 1.5 cubic feet

Maximum Ported Box Volume 2.0 cubic feet

Top-Mount Depth 7"

Cutout Diameter 11-1/4"

Shallow Mount Installation No

Space available is about 46" wide by 31" deep. Height unknown.

Amps pic just for fun.

EDIT:

All Done. Get installed Thursday.

Edited December 7, 2011 by 2007TBSS

[2007TBSS]

Is there a website or something I can go to and have one designed? I kinda have no idea where to start on this.

[412 CVX]

actually if you're not running too much power, that might be more reason to go ported because output might not be very noticeable, especially in such a big vehicle.

your idea with the metal grilles would work just fine if you choose to go that route. designing a sealed box isn't really that hard, really just a matter of playing with the dimensions until you get the right volume. the12volt.com has a nice little volume calculator for rectangular boxes that accounts for the wood thickness.

for ported it's a little more complicated, but still pretty easy if you use torres calculator. you'll have to do a search for it on the forum because i'm too lazy to link it right now (sorry )

[2007TBSS]

actually if you're not running too much power, that might be more reason to go ported because output might not be very noticeable, especially in such a big vehicle.

your idea with the metal grilles would work just fine if you choose to go that route. designing a sealed box isn't really that hard, really just a matter of playing with the dimensions until you get the right volume. the12volt.com has a nice little volume calculator for rectangular boxes that accounts for the wood thickness.

for ported it's a little more complicated, but still pretty easy if you use torres calculator. you'll have to do a search for it on the forum because i'm too lazy to link it right now (sorry )

I saw the Torres calc but frankly, I'm not sure what half the stuff means. I guess I was wondering if there was a tipping point of the box being *too* shallow and if that would effect sound?

[412 CVX]

i suppose it's always possible, but there's no definite answer or rule of thumb, as long as the sub isn't touching the bottom of the box. if you make a sturdy enough baffle to support the subs (and the possible luggage) i doubt you'll have a problem.

i could help you out with torres calculator, it's pretty easy to use. basically you just have to keep track of a few numbers.

post a picture of the calculator and label (with numbers) all the parts you don't understand or are confused about and i'd be happy to explain them.

[2007TBSS]

i suppose it's always possible, but there's no definite answer or rule of thumb, as long as the sub isn't touching the bottom of the box. if you make a sturdy enough baffle to support the subs (and the possible luggage) i doubt you'll have a problem.

i could help you out with torres calculator, it's pretty easy to use. basically you just have to keep track of a few numbers.

post a picture of the calculator and label (with numbers) all the parts you don't understand or are confused about and i'd be happy to explain them.

Basically, the problem I have is I know the L X W but need to know the height. Also, I have never worked with slotted ports, so I would need all the port dimensions and I'm not sure what to tune at so I don't even know what to type in there.

So:

1) Need to know tune frequency

2) Slotted or round ports? Aero ports?

3) If I type in L and W, will it give me H?

4) If I find L, W, and H and tell it I want ported and frequency, will it tell me all box and port dimensions?

Edit:

OK, now how do I add ports? Is there a formula for port dimensions including frequency tune and box size? The sub specs recommend < 2^3ft per sub ported so I left the length full wide and adjusted width to get just under 4^3ft but I assume that will change by the time I add port displacement?? Sorry for the extreme noob-ness. Thanks for your patience.

Edited November 28, 2011 by 2007TBSS

[carshateme]

i suppose it's always possible, but there's no definite answer or rule of thumb, as long as the sub isn't touching the bottom of the box. if you make a sturdy enough baffle to support the subs (and the possible luggage) i doubt you'll have a problem.

i could help you out with torres calculator, it's pretty easy to use. basically you just have to keep track of a few numbers.

post a picture of the calculator and label (with numbers) all the parts you don't understand or are confused about and i'd be happy to explain them.

Basically, the problem I have is I know the L X W but need to know the height. Also, I have never worked with slotted ports, so I would need all the port dimensions and I'm not sure what to tune at so I don't even know what to type in there.

So:

1) Need to know tune frequency

2) Slotted or round ports? Aero ports?

3) If I type in L and W, will it give me H?

4) If I find L, W, and H and tell it I want ported and frequency, will it tell me all box and port dimensions?

Edit:

OK, now how do I add ports? Is there a formula for port dimensions including frequency tune and box size? The sub specs recommend 2^3ft per subs ported so I left the length full wide and adjusted width to get just under 4^3ft but I assume that will change by the time I add port displacement?? Sorry for the extreme noob-ness. Thanks for your patience.

I can make a 3D model of a square box for you if you'd like.

[2007TBSS]

That would be awesome. I need to get the tune and port dimensions worked out first since I would assume it will change my outside dimensions to accommodate port displacement.

Thanks!

[carshateme]

I can do that for you, but I have work, so I'll have it posted later tonight.

[412 CVX]

with this program, you play around with the dimensions of the port and it tells you volume, tuning frequency, and port area in the bottom right, instead of the other way around.

I'm a little confused with your dimensions and i think height and depth need to be switched. also if you're going ported, you're going to want the volume to be a little bigger to accommodate for the port displacement. it's somewhat of a guessing game to find the right volume, but once you find it, it's not terribly difficult from there.

a few things to try after that:

1. click the box that says "sub upward". this tells the calculator that the subwoofer is facing up. (i'll explain why this is important later)

2. if you want the ports to be facing upwards (port holes on the top of the box) then click the "port upward" box.

3. for a slot port, play around with the height width and length until you get the tuning you want. i'd say ~33hz would be appropriate for your situation.

-this is the somewhat tricky part. in the lower right corner you'll see a box that says "port area per foot". In the end you want to keep that number somewhere in the range of 12-16. also, you want to make sure the net volume ends up being what the manufacturer recommends or at least close. in your case the manufacturer recommends around 2 cubic feet per woofer, since you have two woofers, just double that number.

so once all the displacements have been accounted for (woofer displacement, bracing displacement, and port displacement) your box should be ~4 cubic feet, tuned to ~33hz, with 12-16 square inches of port per cubic foot.

you will also need to enter in a value for "# of common port walls"

1 - Port with 0 common walls:

2 - Slot port with 1 common wall:

3 - Slot port with 2 common walls:

4 - Slot port with 3 common walls:

check back when you've done this.

Edited November 28, 2011 by 412 CVX