12" 07' RE XXX | Constructing Enclosure | plexiglass panel | 2.487c^3 | PICS

[Oinkypig 10+ year member]

This will be my second build for a 2007 12" RE XXX subwoofer. This will be going in my 1995 jeep wrangler. Im just posting this to verify that all my calculations are correct. Now for some info. My enclosure will be constructed of 3/4" thick MDF. the port will be 5" wide and 11.5" in length. 5x11.5=57.5 sq in of port. Most of other dimensions included in pictures.

Here are all my calculations

33x19x13 air volume

31.5x17.5x11.5/1728=3.6686197916666666666666666666667 enclosure volume

11.75x9.75x.75/1728=0.049723307291666666666666666666667

9x15.5x.75/1728=0.060546875

0.110270182291666666666666666666 plexiglass non-displacement

3.6686197916666666666666666666667 gross volume

+

0.110270182291666666666666666666

=

3.778889973958333333333333333332 gross vulume w/ plexi non-displacement

12.5+.75+2.5+2.5=18.25 length from opening to end of port 1

33.68-18.25=15.43-----15.5 18.25+15.5=33.75 port length

5.75x11.5x33.75/1728=1.29150390625 port displacement

3.778889973958333333333333333332

-

1.29150390625

=

2.487386067708333333333333333332 net volume

-

.24 sub displacement

=

2.247386067708333333333333333332 net volume after displacement

Click to read more...

 

[Oinkypig 10+ year member]

haha yes i no

 

[dennis09x 10+ year member]

This design is sweet and is just like what i'm trying to make (08 xxx 12" with same tuning and displacement just with a diff plexi window and port size). What i want to know is if there is an acoustical advantage to having the sub firing up into the hatch or backwards into the tail lights or the port firing up into a hatch or into the tail lights. Its putting ahold onto my design

 

[ventilla]

this design is 41.57 hz

because in cf go 2.48 cf

incriminator audio say

You always use CF internal when you use QuickBox Elite!

IA Nick Wright

program design

//content.invisioncic.com/y282845/emoticons/redface.gif.62fdbfe1a101588a808c4cff71bcb942.gif and you put the total enclousure vol 3.77cf

 

[Immacomputer 10+ year member]

All that precision and your design is still VERY far off from what you want.

Your design is about 2.11 cubic feet tuned to about 41hz (or really 2.11136667ft^3 @ 41.36hz if you're obsessed with being exact //content.invisioncic.com/y282845/emoticons/rolleyes.gif.c1fef805e9d1464d377451cd5bc18bfb.gif )

Your port length is actually 36.25" and your internal volume is wrong.

You measure your port length based on the center line down the port with an end correction that is 1/2 the width of the port. In this picture with your given dimensions, the selected area times 11.5/12 is going to be the volume before sub displacement. The line down the center of the port is the effective port length that you should use, not the walls of the enclosure:

Unless I translated your vague (as far as internal wood dimensions... we don't give two shits about the plexi window dimensions) cad drawings incorrectly, you should start over.

 

[Oinkypig 10+ year member]

3.77cf IS my internal volume. and u cant put in 2.48 for the cf because quickbox elite is used to determine the port length. 2.48 is with the port displacement ALREADY subtracted from the total internal volume. You cant put in the internal volume with the port displacement factored in when you are trying to use QB elite to figure how large your port should be.