Introduction: Acrylic Subwoofer Enclosure for Under a Car Seat.

By
About: electrician in pittsburgh.


Hello hello. First off this is my first instruct-able and as such i welcome and questions and comments that come my way and will entertain them as best i can.

My scooby is kinda small ... so space management is a must and was my main concern for this build. This box can built by any novice (like me) with minimal effort and time for around $100 in material (excluding the sub/amp). Enjoy

Things you will need:

1) 1/4" thick {the thicker the better} acrylic or plexi glass
2) quilt batting
3) acrylic glue {i hear acetone from a saloon works also but not sure}
4) silicone
5) fine pointy paint brush
6) 1"- 1.25"self drilling #8 or #10 screws to attach the sub-woofer.
7) duct tape and sand paper
8) jig saw or dremmel
9) sub-woofer and amplifier
10) drill, basic hand tools, and a socket set
11)  table saw or circular saw will make your life much easier
12)i think that's everything... lets get started!

Step 1: Can You Feel.... the Bass?

first do some math and measuring as every car will be different. i have a 2007 Subaru Impreza 2.5i and i came up with an enclosure size of 5and 7/8" total  enclosure height {6.75" tall with sub }  12.5" wide and 14.75" long. 

After you measure find the surface area of the cube with LxWxH for each side (a cube has 6 sides) and go out and procure your acrylic... or lexan... or whatever.

***side note*** i chose acrylic b/c its cheaper than lexan and way better than wood for its size... at least that's what i think i learned from all those forums.

*** fun fact ***  the enclosure is also not supposed to be a symmetrical shape due to re-verb and sound distortion .... something along those lines.... but i have had little if any problems like that with my build.

*** also under my seat i have re routed some cables for the air bag sensor and bent some metal out of the way and gained some extra room***

*** remember to leave height for butt clearance if you ever plan on having a passenger***

Step 2: Its Box Makin Time!


measure out your material and get a game plan so that you can efficiently use the acrylic with little waist... in my mind its not cheap.

***Clean 90 degree cuts are essential for later steps so take your time b/c spending 10 extra min. here will save you hours later***

cut out your squares and rectangles and doo dads and what nots.. do not throw away the little peices of scrap as you can use them to suport your joints when you glue it all up. (note all the long pieces in the back left of the picture)

i had some leftover jacks from my last sub enclosure so i used it... simply whole saw or drill a few small wholes around the perimeter and use the jig saw.
***as seen in the picture.***


now is the time for you to mark up the sub-woofer hole and using the same method drill and cut it out.

*** typically for a 10" sub you need about a 9.75" hole but every sub is different and each manufacturer should have that info somewhere in the instruction book***

Step 3: Making It All Stick.

using sand paper rough up all your pieces where you want to make the bond... i got a little carried away and roughed it all up. at least now it's consistent. haha


my old man had this UV proof lexan bonding magical chemical from his past life as a sign maker... so i used that... im not really sure what it was or where you get the stuff but he also said that acetone from a hair styling place would work for acrylic.

piece together all your pieces one by one ... use this video if you need a crash course. i used the paint brush to apply the weld.

http://www.youtube.com/watch?v=hT6Ow_cBTps

first weld everything up... then go back and add your support strips along the corners for extra strength.       *** this is where i used those long strips ****


***ADDED BONUS! ***i believe these little strips in the corners are the reason i don't have sound distortion.


tape it all up for strength and allow it to cure for a day or two.

after it cured i ran a bead of silicone around all the edges for good measure

Step 4: Tell Me Why Do We Build Castles in the Sky?

the end is in sight. 

use about 3/4 of the quilt batting and fluff it into your box do not pack it in like a folded towel.

the reasoning for the batting is this:

http://www.avsforum.com/avs-vb/showthread.php?t=1062977

in my mind it is beneficial to use this method b/c the box is already almost undersized for the sub. and i am very happy i did. i tried it with and without stuffing  and preferred it with the poly fill but by all means try it for yourself and do what you think  is best.


Step 5: I'm Your BbBasscreator

Install Mr. Sub-woofer with the self drilling screws very carefully b/c it is very easy to crack the acrylic when doing this.

*** note: if you do manhandle it and you get a crack or two you can always try and seal it up with that magical welding solvent or acetone*** 

(still not entirely convinced about the acetone being effective)

Step 6: I'm Pickin Up Good VVviiBbrations

ok so now you have a complete install like me... but then you realize you just a lot of hard work into an enclosure with a really cheap crappy sub in it....

i could not let this be the end of my project. its sound most certainly did not make me happy. so off to the store i went to get a new sub for my new enclosure and new amp.

i fit the sub into the box and realized it was 1/4 too tall now... so i just whole sawed through the bottom of the box the same size as the magnet and everything turned out just fine... in fact it sounded better now that the box was ported. haha

bolt the seat back on and make sure everything had clearance... i have no clearance now... its a perfect fit.

i put the sub under the passenger seat and the amp under the driver.



*** also if you may like to check out  www.hypem.com/cheesehead for some good vibrations***


well that's all folks. hope you enjoy your as much as i do mine.