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381 Posts
Discussion Starter #1
Hi all, over the past weekend a friend and I put together a sub box for a 10" kicker sub that some have done in the past, but little to no details in the threads I have found remain. Basically I wanted to transform the ski-pass into an area for the sub to face out of into the cabin. I have a rear strut bar that we had to work around, so if anyone is interested in having both like myself, this guide will be useful. If no strut bar is wanted, the depth of the box can be increased.

Certain parameters can be changed for your install, this is simply how it was accomplished for me.

All the tools you'll need:
Table saw with adjustable angle (not required, but nice to have)
Jig Saw
Palm Sander
Circular saw with adjustable angle
Appropriate Torx bit for screws

Time Required: 10 Hours
Number of people preferred/required: 2/1

Here are all the things we used to make it happen:

Total Price at the time of my purchase: $330.72 USD

Here are the dimensions:


Total interior volume: 0.88 ft³ - This volume is the minimum for the specified speaker for optimal performance.



1.) Start by removing the back seats, the bottom will pop out of the tabs and should just pull right out. My tabs were broken, so this was especially easy to do.
2.) Remove the back side of the seat by removing the four 14mm screws holding it in place.
3.) Pop the seat belt retention hooks to release the seat belts. (This can be done by gently prying with a flat head screw driver)
4.) Once the back seats are removed, you should gain access to the ski-pass enclosure.

*Note: My ski-pass enclosure was broken, I believe the trunk side cap thing is the only thing missing. The rest was bolted appropriately.

5.) Remove the 10mm bolts holding in the ski-pass cover
6.) The ski-pass should fall right out and can be discarded or saved in case of a stock conversion.
7.) Remove plastic molding from the trunk that will serve as the outline for the back plate of the enclosure, this can be discarded or saved in case of a stock conversion as well.

Begin Back Plate construction:

8.) Taking the back plastic and place on top of MDF, then trace and cut the outline. (Note: about half an inch or so will stick off the sides, completely fine)
9.) We noted that the last ~5" of the outline from the back plastic got in the way more than trying to make it work, so we decided to completely leave that part out as shown below.

Note: That ~5" will be replaced with a small block created later on.

10.) In test fitting the back plate in the trunk, you will notice that it needs to be beveled, at about 30°, this can be accomplished with a table saw, or circular saw


Begin box construction:

Note: Before securing all panels with wood glue, test for fitment! (mainly the long pieces that will rest on the sides of the wheel wells)
Note: We did not account for the displacement of the carpeted covers that flank the sides of the trunk since they were removed for ease of installation

11.) As the above photos show, begin cutting the dimensions needed for each of the sides.
12.) Once all sides have been cut, apply a liberal amount of wood glue to the panels and place flush with edges.
13.) Using Torx wood screws, place approx 8 screws across the 2' 7.25" long sides, and 4 screws (2 included from the previous 8) across the small sides. This is the same for attaching the back side.

Note: Using the screws in the parts list showed some splitting of the MDF, which a small amount is acceptable. Major cracks can lead to a loss of performance.

14.) Once all sides have been secured. Go on the inside of the enclosure and run a liberal amount of wood glue across the creases. This ensures maximum sealing for best acoustic performance.
15.) Once all sides have been sealed with wood glue, begin attachment of back plate to enclosure.

Note: We sanded the edges with a palm sander, while not required, it is recommended for nice installation.

Begin speaker installation:

Note: Test fit the speaker unit if yours is different from the one listed in this tutorial


Note: Make sure to be on the inside of the enclosure! You do not want to make contact with the sides of the enclosure.

16.) Using the cardboard molding provided with your speaker, center and outline the circle on the back plate to be cutout.
17.) Using a drill, make a 1/2" hole 1" on the inside of the outline
18.) Using the jig saw, place the blade in the hole and cut about 1/8" on the inside of the outline for the speaker and cut out the hole.
19.) Test fit the speaker like shown below, but DO NOT ATTACH:


20.) Drill a small hole on the speaker facing side of the enclosure for the speaker wire to pass through.
21.) Using wood glue or silicone, pass speaker wire and seal the hole, make sure to not connect or fully install the speaker, this is done later! Also make sure to leave enough wire for easy installation.
22.) There is going to be a small piece of wood to hold the entire enclosure in place from the bottom as previously mentioned.
23.) When test fitting the entire assembly, you will need to gauge the height of the piece, I don't recall the exact height, but it should be about 2-3"


Note: The enclosure will come about 1/2" from a rear strut bar if the dimensions have been followed up until this point.

Note: The size of this block will determine the height of the speaker on the inside of the vehicle. Be sure to go back and adjust the height until satisfactory.
We did not do this step properly and as you will see below, the top of the ski-pass needed some slight persuasion with a hammer to ensure a proper seal.
Test Fitting is your best friend!


24.) This piece will be about 12" wide to cover the ski-pass
25.) This piece will also need to be beveled at approx 30° on both sides to contour the trunk for proper fitment.

Begin Enclosure Carpeting:

26.) Once the final dimensions have been determined, with each piece being test fit, start cutting the carpet to the appropriate lengths.

Note: Do not be wasteful. The product link in this tutorial is just enough for this project.

27.) Using the 3M adhesive, apply to MDF and carefully place carpet ensuring no air gaps for proper appearance.
28.) Once all the carpet has been placed. Begin final assembly.


Final Assembly:

29.) Start with the small spacing block you created and using two of the self drilling screws, drill from the cabin through the sides of the ski-pass to secure the spacing block as shown below.


Note: The spacing block and back plate will not have a perfect fit, as shown above, unless you try to make it so.
The speaker should not be installed to the back plate, the above picture is just for fitment purposes.


30.) With the help from a friend, have them push on the enclosure from the trunk.
31.) Lift up the insulation matting and using 4 self drilling roofing screws, with 2 on each side, secure the enclosure to the vehicle. Any more than 4 total screws is not required unless desired.

Note: Make sure to not screw on the elevated portions of the rear firewall! You want to drill on the metal closest to the enclosure.

32.) Once the enclosure is properly secured to the vehicle, begin wiring and securing the speaker unit.

Note: My speaker was wired in parallel. I am not going over any wiring in this tutorial, that is for you to research since each setup is unique!

33.) I do not recall the screws used for this step, but I know they were not the Torx ones or the roofing ones. Use your best judgment and be careful to break the plastic on the speaker assembly

34.) Once the speaker has been secured, the remaining steps are to reinstall the seats and finish the amplifier wiring. This includes the capacitor, which I mounted on top of the enclosure as shown below.
35.) That's it! You should be done. If there is anything I missed, post below to ask any questions. Thanks for reading this far!

Note: Like mentioned above, I will not be going over amplifier wiring or placement, as each system is unique. However I will post photos of how I solved the problem.

This is a panorama, the bar is NOT bent haha

It looks like I've hit the limit on uploads, but this is the end, so hopefully this helped at least one person.

EXTERNAL LINK TO PHOTOS AND ZIPPED GUIDE: Car speaker enclosure - Google Drive
(it will include pdfs of the products for reference!)

955 Posts
Nice! I was going to make one for the wagon to sit instead of the fake floor above the spare tire, but gave up in the end with a lack of time and motivation. Then i got too old and couldnt be arsed listening with the sub on all the time . . . :rolleyes::LOL:

381 Posts
Discussion Starter #3
Nice! I was going to make one for the wagon to sit instead of the fake floor above the spare tire, but gave up in the end with a lack of time and motivation. Then i got too old and couldnt be arsed listening with the sub on all the time . . . :rolleyes::LOL:
Haha, I have to have the gain knob turned down to about 10 or 15% for casual listening. I guess if I ever have friends who want to push it, they can.

But I gotta say, this setup hits harder than a few of my friends' cars, great performance out of a 10" 2Ω driver.

My next project is redoing that area around the spare tire. Since I don't have one, the carpet just sags and it makes it difficult to put things in the trunk.

955 Posts
Yeah mine had a switch to turn off the amp when the wife was in the car, she hates the bass :rolleyes:

381 Posts
Discussion Starter #5
Yeah mine had a switch to turn off the amp when the wife was in the car, she hates the bass :rolleyes:
My friend's wife is the same way, I doubt the both of the will ever be in my car from now on, the entire back seat is basically a massage chair at this point haha :ROFLMAO:
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