View Full Version : Box for 15" elemental

04-06-2003, 01:10 PM
i have an elemental designs 15" dual 2ohm sub (k-series). i need to make a box that will fit in my trunk and still give me some room to use it. i will be running about 450 watts to it daily. here are the measurements i have to work with:


what can i do with these #'s? i want it to be ported as well so i need someone to help me figure out all of the measurements.

any help is very appreciated

04-06-2003, 01:50 PM
please, someone help...

04-06-2003, 02:45 PM
im in the middle of building a sealed box for that same driver, dimensions are H-17" W-18" and D-19" about 2.5 cuft after displacement. dunno if this helps any since it a sealed box but if ya change ur mind and wanna go sealed there ya are

04-06-2003, 03:44 PM
i dont need new numbers, i just need to know how many cu. ft. im going to get out of it if it is that size. the measurements might be too big and i might have to change them. how do i figure out how many cu. ft. that is?

04-06-2003, 04:14 PM
using 3/4" MDF you'll have about 2.93cu ft.

-2.84cu ft after subwoofer displacement.

-e15k .085cu ft displacement

That should be big enough to go ported.
What freq do you want the box tuned at?

I'm building a 3.5cu ft ported box for an e15k right now.
Tuned @33Hz
I'll have it running tomorrow.

04-06-2003, 04:16 PM
i dont know anything about frequences or any of that. how big does my port have to be?

04-06-2003, 04:17 PM
how did u figure how many cu. ft. mine was?

04-06-2003, 04:27 PM
Originally posted by coolman91985
i dont know anything about frequences or any of that. how big does my port have to be?

Well the freq the box is tuned at directly effects the
length of the port.
Higher freq = more SPL "louder" = shorter port
Lower freq = more SQ "better sound quality" = longer port

LxWxH=total cubic inches
then divide by 1728 to get cubic feet

The thickness of the material used has to factored in as well.
You have to subtract the thickness of material to get the
internal volume of the box.

Do you plan on slot porting the box?

04-06-2003, 04:43 PM
i dont know. should i? whats the difference?

04-06-2003, 04:50 PM
Yes I would use a slot port because you will be able
to tune lower with your box size.

It will give you more port volume.

Are you more into SPL or SQ?
This will help determine a tuning freq.

04-06-2003, 05:18 PM
i like the thump, but i want to be able to hear the words clearly and have clear bass. i hope that helps...

04-06-2003, 05:40 PM
For a good mix of SQ and SPL a tuning
freq around 33Hz would be fine.

With your dimensions you could use a slot port
that is 15" x 2" opening and is 20" long.

The port area is 30sq in. fine for e15k

This size port should give you a tuning freq
right around 33-34Hz.

The longer the port the lower the freq.
Which will give you deeper bass.

The shorter the port the higher the freq.
Which will give you louder bass but not as deep.

Here's a sketch of the slot port box design.

04-06-2003, 05:45 PM
that doesnt look easy to make... is it easier than it looks?

04-06-2003, 05:47 PM
my box is only going to be 11" deep. do i have room for this?

With your dimensions you could use a slot port
that is 15" x 2" opening and is 20" long.

04-06-2003, 05:51 PM
It depends on if your good at woodworking.

You just have to take your time and double check
everything before you cut your wood.

Have you made a subwoofer box before?

Use 3/4" MDF medium density fiberboard. Works great!
Usually about $18 for a 4'x8' sheet at LOWE"S
or Home Depot.

04-06-2003, 06:07 PM
i made my last box. but it was sealed. how would u cut the wood for the slot port? do u just make seperate walls and then glue them together (or nail)?

04-06-2003, 06:13 PM
when u said it needed to be 20" long, did u mean total or from front to back (counting the curve)???

04-06-2003, 06:22 PM
20" is the total length of the port.

You'll go straight back 9.5" and over 10.5"
for a total of 20"

04-06-2003, 06:24 PM
and the port is 2" wide, right?

04-06-2003, 06:25 PM
thanks for all of ur help. i really appreciate it.

04-06-2003, 06:32 PM
Yes, the port is 2" x 15" and 20" long

I will have my e15k working tomorrow
in a 3.5 slot ported box [email protected]

Since we have the same sub I'll let you know
how it sounds and give you some feedback.

What kind of auto you putting your stuff in?

04-06-2003, 06:33 PM
1998 nissan sentra 4 door

04-06-2003, 06:34 PM
does the port have to stay 2" wide at all times? if i stop after 9.5", then that ouwld only leave 1.5" for the rest of the port. wouldnt it?

04-06-2003, 06:52 PM
Yes the port must stay 2" wide all the way.
Remember that the material takes up 3/4" on
all sides.

The internal depth is 9.5"

you need to make the section of wood that goes
straight back 7.5" long that will leave a 2" gap.

Then you'll attach another section to make the
bend in the port. It needs to be 9.0"

04-06-2003, 06:55 PM
ok, thats what i thought. thanks again...