Custom Sub Box Install- pics and plans
 

While I'm relatively happy with my Bose system, I feel it really lacks any semblance of bass. I had a Bazooka 10" in my Miata's trunk, which did exactly what I wanted- filled in the low's with solid, tight bass that was heard in the car, not out of it. I wanted the same for my RX8, but I wanted to take advantage of the larger trunk to create a small enclosure with a little more power.

This weekend I put together a custom subwoofer box with plans I made in Visio after measuring the space I wanted the box to occupy (basically the space between the seats and the back lip of the trunk). I wanted clean, tight bass in a small package so I went for a sealed box design at the minimum recommended volume for my subs of choice (Alpine 10" Type E "budget" subs :). It's been about 15 years since I last built a box, so I wanted to do this one right- I used 3/4" MDF, liquid nails, sound deadener spray, polyfill, speaker gaskets, OFHC 10Ga speaker wire and power wire, etc.

Anyway, if anyone is interested, I'll convert the plans from visio to GIF and post them... but for now, below are a few pics of the box, pre-construction and installed.

The components- Alpine 10" Type E's and Alpine 350watt Class D mono amp sitting on my favorite creation, my tiki bar : )

The pieces cut and laid out...

The pieces put together in a test-fitting...

The finished product carpeted with speakers and grilles installed...

The finished product from behind, with amp installed and wired into speaker terminals...

The box installed in the trunk and wired up...

and another...

and the last...

very nice!

The last two shots really show how much trunk space is left. I did have to remove my spare tire and mounting kit (I didn't really want it, but it was already installed on this car when I found it on the lot). I maximized space by matching the slope of the box's face to the slope of the back seats (65 degrees), and making the bottom just large enough to easily slip in and out if I need to remove the box for long trips, etc.

As for the sound- it's exactly what I was looking for- not ear shattering or sheet-metal rattling- just low, tight bass to supplement the Bose. I still have some tweaking to the cut-off and gain to make it agreeable to all types of music, but it's helluva improvement so far.

As I mentioned- I'll convert the detailed design docs to .gif if there's any interest.

-Sean

Yup, lookin good...

Absolutely amazing man! And you still have room to throw your crap in the back! I wish you were in FL to make me 1. I would pay high dollar for that.

Very nice job, I'm impressed! :)

Just shows you how much room there is in our 8's...

Thanks... the last sub box I made was in your neck of the woods (St. Pete), btw... but that was many, many moons ago : (

Thanks!

Yeah- I was amazed how much space was back there when I pulled the spare tire. That damn thing takes up so much room, and effectively blocks even more from being usable below it.

One aspect of the design I didn't mention was to make sure that the "emergency tire repair kit" still had room to attach to it's factory strap, so I didn't have to find another home for it.

Wow man, that's really nice. I bow before you... excellent work.
I think the rear passengers will get a good back massage when you turn that thing up :D

I had some time to convert the plans to .gif from my other PC and put them on my server:

http://www.theswamp.com/rx8/rx8boxplans.gif

Something I didn't mention earlier is that these plans will adapt easily to a 2x8" setup, 1x 10", or 1x 8" - the latter two by omitting the center divider piece.

If anyone finds it helpful, enjoy!

Here's a preview...

DONE thanks man for taking the time to do this...... yet another thing that would be great on a DIY Forum!!

Thanks for the info man! I really like this design!

Just glad to give something back to the community : )

If anybody builds from these plans, I'd love to see pics of the results.

-Sean

G8rboy - Very well done!!!! I went to the link and it looks very thorough, thank you for your time and effort on this.

Couple ques. - Did you tap into the rear speakers and as a result is there any interference or static?

Why do you need the board to separate the two woofers? Is the sound distorted if it isn't used?

Thanks in advance.

Thanks Success- yes, I tapped into the rear speakers since my amp has both line-level and speaker level inputs. It sounds fine to me- no interference at all. I am however planning to also try to find the low-level inputs in the wiring harness that plugs into the rear Bose amp and run those into the RCA low-level inputs for comparison. I'm curious to see what effect, if any, the audiopilot has with both setups.

As for the partition between the woofers- some say you don't need it, some say you do. Maybe Rotarygod or someone with more experience with subs will answer this more definitively. I figured if they both had their own private air space it would be the optimal situation. If I had been looking for "boomier" sound for rap/hip-hop, then I would have probably just done a single 10" in the middle with no partition, essentially doubling the airspace the sub could have. It's a pretty flexible design...

-Sean

that is very clean

you can hardly see it

i am very impressed! Awesome job!