1. ## Need some help figuring internal vloume, and port area

Second image is where my 2 amps r going to sit ( 18 " x 12" x 3" ) per rack, numbers are kind of hard to see

My Box design, assume External Dimensions shown, 3/4" MDF for build.

How much airspace is in there?
Port dimensions?

Id like to use 2 ports fireing towards roof, opposite ends of the box.

Thank you ahead of time for any help. Im trying to figure if I can fit 2 DD 3512's in my truck.
Last edited by twistedmind; 06-08-2008 at 06:40 PM.

2. ## Re: Need some help figuring internal vloume, and port area

I realize right now im going to have a issue with the top subs mounting depth, what I had in mind was to replace my stock bench seat with a pair of racing bucket seats and building the actual sub mounts forward another 6 inches ( between the seats, Ala Corvette style ) and useing fiberglass to get the correct mounting depth, this is just a basic do I have enough airspace available sketch.

3. ## Re: Need some help figuring internal vloume, and port area

I'll help ya out here with this, but I want know what vehicle this enclosure is being designed to fit.

4. ## Re: Need some help figuring internal vloume, and port area

Originally Posted by Mr Cabinetry
I'll help ya out here with this, but I want know what vehicle this enclosure is being designed to fit.

2k regular cab f150 short bed

5. ## Re: Need some help figuring internal vloume, and port area

Originally Posted by twistedmind
2k regular cab f150 short bed

Enclosure total volume is 5.08 cu.ft

The two amp rack sections displace .68 cu.ft.

That leaves you with 4.39 cu.ft. before any additional displacements.

6. ## Re: Need some help figuring internal vloume, and port area

Thank you so far my man, Now if you would be so kind as to do a touch more math for me.

Useing the following measurements

Port Area (sq in) 44

Port Length (inches) 16

per sub woofer, whats that going to leave my internal volume at, once again assuming 3/4 mdf for port build.

Also, could you give me a hole size to make? example 12 inches long x 3 inches wide x ?? deep = 44 sq in of port

thats off the DD sight, those are the only specs they list other than woofer displacment, and box volume

the sight recommends 2.5 cubes per driver

the subs displace .336 each

^^^ x2

8. ## Re: Need some help figuring internal vloume, and port area

FYI since you do this for a living this box as is right now will fit behind the stock bench seat

9. ## Re: Need some help figuring internal vloume, and port area

well... if the total interior volume is just about 4.4 cubes before any displacements, thats about 2.2 cubes per sub w/o port disp. and sub disp. so i dont think your gonna get your 2.5 cubes per sub

10. ## Re: Need some help figuring internal vloume, and port area

well, thats also depending on how far out the top sub will extend with the FG.

11. ## Re: Need some help figuring internal vloume, and port area

Originally Posted by dannyz122001
well... if the total interior volume is just about 4.4 cubes before any displacements, thats about 2.2 cubes per sub w/o port disp. and sub disp. so i dont think your gonna get your 2.5 cubes per sub

im going to do some extensive fiberglassing where the subs are, its going to extend out from the main box. im just trying to figure out how far out it has to go before I hit 5 cubes after ports.

so example, my racing seats are 23" wide at the widest point x 2 so 46" of seat that leaves me 17" between the seats to expand towards the dash to make up some airspace.

12. ## Re: Need some help figuring internal vloume, and port area

Originally Posted by twistedmind
Thank you so far my man, Now if you would be so kind as to do a touch more math for me.

Useing the following measurements

Port Area (sq in) 44

Port Length (inches) 16

per sub woofer, whats that going to leave my internal volume at, once again assuming 3/4 mdf for port build.

Also, could you give me a hole size to make? example 12 inches long x 3 inches wide x ?? deep = 44 sq in of port

thats off the DD sight, those are the only specs they list other than woofer displacment, and box volume

the sight recommends 2.5 cubes per driver

the subs displace .336 each
Give me a few, I'll have answer for ya.

13. ## Re: Need some help figuring internal vloume, and port area

Port Size as follows - I. D. Size - 2.8750" x 15.3750" x 15.25" = .54 cu.ft.

That is also accounting for 3/4" MDF and the reason it's 15.25" length and not 16" is the 3/4" thickness of the top MDF is not part of the displacement.

So, to recap:

Enclosure total volume is 5.08 cu.ft

The two amp rack sections displace .68 cu.ft.

That leaves you with 4.39 cu.ft. before any additional displacements.

Subtract for slot port & walls( 3/4 ) = .54 cu.ft.

Volume now is 3.84 cu.ft.

14. ## Re: Need some help figuring internal vloume, and port area

Originally Posted by Mr Cabinetry
Port Size as follows - I. D. Size - 2.8750" x 15.3750" x 15.25" = .54 cu.ft.

That is also accounting for 3/4" MDF and the reason it's 15.25" length and not 16" is the 3/4" thickness of the top MDF is not part of the displacement.

So, to recap:

Enclosure total volume is 5.08 cu.ft

The two amp rack sections displace .68 cu.ft.

That leaves you with 4.39 cu.ft. before any additional displacements.

Subtract for slot port & walls( 3/4 ) = .54 cu.ft.

Volume now is 3.84 cu.ft.

did you just figure for one port, or 2 ports?

if 2 ports is the 2.875 x 15.375 x 15.25 for each port? Or did you combine them into one massive port?

15. ## Re: Need some help figuring internal vloume, and port area

a real quick rendering of what my fiberglassing will do minus the sharp edges

so just this little minor addition adds over 2 cubes to the enclosure.

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