Box Design Help Please

[soundbwoy]

Hi SMD family,

I could do with help with a box design for 2 dc level 4 15" m1's on a sundown 3500d at 1 ohm. The max dimensions are:

H: 19" x W: 39" x D: 18.25". If possible could the box be ported and tuned to 32hz. If any more info is required just ask

Thank you

[Joe X]

Yes, what's the vehicle these are going into.

[soundbwoy]

Sorry I forgot to mention, it's going into an audi a3 8p1 2.0fsi.

[Joe X]

On those dimensions you don't really have the space for two DCL4 15s ported, I could find you nearly 5 cubes NET using partially external aero ports at about the tuning you want BUT you would need about 6-6.5 cubes so really low, sealed you could do or a single 15" ported.

[soundbwoy]

I know it's really tight, unfortunately I have no space for aeros, I already have the equipment, but I've recently changed cars, and want to get my stuff in the new car, and out of my way!! Lol. What would happen if they were put in too small of a box, but more power? Would it effect the subs in a negative way?

If possible could I have a design just to try out please?

[Joe X]

A box with that would make use of the slant of the backseats would likely gain you space, if you give a top and bottom depth, it would help quite a bit also going half an inch taller would help. Try to find all the space you can.

[Joe X]

So the following would barely meet the spec for ported if you can fit it, it's slanted to gain the space right behind the backseat:

It's 6.3 cubes NET @32Hz 57 square inches of port.. on the limit no doubt but it would still work.

[soundbwoy]

Hi Joe

Thank you for the design, I've had another measure up, I'm pretty much at the most for the height with 19" and width with 39", the top depth is also at most with 18.25", but at the bottom i can squeeze 23". Is there any way we could work with this at all? Also would slot ports take up less room compared to aeros?

Thanks in advance

Soundbwoy

[Joe X]

Ok so here is a spec based on your corrections, aeros are the most space efficient ports you can use, a slot port would need more space, also the top and bottom sheets have a slanted (front) side and that's the reason two depths are listed for those parts, the aeros will need a 90 deg elbow to meet the length for the shown tuning frequency, both the pipe and the fittings are easily available at home depot, lowes, etc.

Enclosure Specifications:

Fb = 32.8 Hz
Vb = 6.2 ft^3

External Height = 19.125 in
External Width = 39 in
External Depth = 23 in 76.1 deg.
External Depth2 = 18.25 in 76.1 deg.

Cut Sheet List:

* All Dimensions in Inches.
* Wood Thickness is 3/4 for all Parts.

External Enclosure Parts:

Front = 18 3/16 x 39 (top/botton cuts: 13.9 deg.)

Top = 18 1/4 , 18 7/16 x 39

Bottom = 23 , 22 13/16 x 39

Back = 17 5/8 x 39

Left & Right Sides =
Top = 16 15/16
Bottom = 21 5/16
Back = 17 5/8
Front = 18 3/16

Port Quantity and Dimensions:

Number of Ports = 2
Pipe Port Diameter = 6
Pipe Port Length = 17 3/4

Assembly guide (generic dimensions):

Important notes:

- All boxes built outside the car need to fit in their way in not just have the right dimensions.

- The ports needs 6" of free airspace in front of them for proper operation.

- Setting your amp subsonic filter to 28Hz is suggested.

- Bracing is a single 1 1/2" wooden dowel rod top to bottom at the center of the baffle.

[soundbwoy]

Thank you for all your help on this Joe. I can't wait to start building