View Full Version : box cubic ft question

04-04-2010, 03:44 AM
building a box for 2 15in DC XL's. 33hz tuning.

is 5.5cubes per sub after woofer displacement overkill?

04-04-2010, 04:06 AM
I guess I should ask this also:

Should I double baffle the whole box or just the sub side?

using grade A 3/4 inch mdf.

04-04-2010, 04:19 AM
If you build a divider inside the box to seperate the two subs. That can act as your brace. If you do not do this. Then double layer front and 2 side baffles so you have good connection from wood to wood. And no 5.5 cubes is not overkill. The bigger the box. The lower it gets and the less power you need to move the subs full tilt. Even if you tuned that box to 45. It would still get down low due to the size of the box. It's all on how you build it bro.

04-04-2010, 04:32 AM
Not overkill. Nice.

04-04-2010, 04:41 AM
how much power each

04-04-2010, 04:44 AM
The most he will need is around 1500 to 2kw *per sub

04-04-2010, 04:55 AM
1500rms each for now. maybe 1750rms each down the road. I was planning on doing a window brace between the subs and keeping the box single chamber.

So perhaps I should tune a little higher with the cubes I plan on having? maybe 38hz ish?

Space I have to work with : Could probable go a bit bigger, but need room for extra batts, Amps and airflow.

H 26"
D 39"

Subs firing up and port firing towards hatch. I have more Height, but leaving space for the air to flow from the rear hatch to the front of the car. Love that my rear hatch is well rounded :D

Amp: audiopipe AP30001D. Price on that amp is so low I just couldn't pass it up.

EDIT: should list my car too - Scion XD 08

04-04-2010, 10:54 AM
There's no reason to go that big unless you won't be able to push the sub properly in a normal sized enclosure(4ft^3 or so). Realize that mechanical power handling will decrease a bit with such a large box. And since I'm not too familiar with what it takes to move an XL, I can't tell you if the ap3000d is enough or not.

04-04-2010, 02:48 PM
im going with 4 cubes each woofer after displacement. also going double baffle only on the woofer side. using a windowed brace between the woofers for support.

will post a screen of the box sketchup after I get back from peddling this amp.

04-04-2010, 03:17 PM
decent design?


04-04-2010, 07:28 PM
Thought you said you were only doing a double baffle?

04-04-2010, 07:49 PM
This was my original layout (modified for 4 cubes per). Since I already have the MDF, I figure I might as well stick with it. It's hard to make up my mind. I think that this might sound good when all is said and done.

What do you think might be better? I'm open to suggestions.

04-04-2010, 07:52 PM
No problem with doubling everything if you have the mdf and don't mind the extra time cutting/building. I don't think it's necessary, but it's not going to hurt anything, obviously. What side will the subs be mounted on?

04-05-2010, 02:18 AM
subs mounted top side firing up and port firing towards hatch. Should be enough space around the box for the air to flow towards the front cabin fairly unobstructed. dynamatted the whole car with triple layer in rattle prone areas.