Spare Tire Subwoofer!

[B 4 You]

Post 1
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Alright, bear with me, i have lots of pictures coming. wait for them to load. i will number the posts in order at the top of each one.
i have my post set so that the oldest ones show first, with new ones descending. if yours is different, then change it or deal with it. :P

to start, this is my first every subwoofer job, first time using fiberglass, first time messing with cable this large, etc.
i know it isn't perfect, but i think it came out nice and i really like it. :]

now onto my story...

Well, I wanted to create a subwoofer for my car. I like having trunk space though, so I had a dilemma. I thought about sticking the box where my spare tire would go, but I like having my spare tire in case I need it. After some thought and instantly forgetting about an under the seat subwoofer, I had the idea of putting the speaker inside the spare tire. A quick and I came up with this box someone else had made:
http://www.i-club.com/forums/showthread.php?t=198934



I did some research, and discovered that it had successfully been done before. I quickly looked for a shallow mount subwoofer and a thin amp.

The subwoofer: Boss Audio NX10FD



The amp: Power Acoustik STAX4000/1D



The Plan:



After planning it out, I took a big piece of cardboard, and cut a hole in it where the spare tire would go. It’s the same shape and size as that piece of particle board that goes over the spare tire. I duct taped the cardboard to the tire.



I ran the duct tape the entire way around, making sure no cardboard was showing.



I went to autozone, bought some Bondo fiberglass mat and resin, and went to work.
The lighter color is tin foil that I put on to make sure it was completely sealed. After about 3 layers, the glass was rock solid. This is the first layer.



A little spray paint for cosmetics, and I measured for an MDF lid.



Prying the fiberglass from the spare tire was almost impossible and took forever, but this is
what it looked like after pulling it off. The black is a little spray paint.

[B 4 You]

Post 2
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Went to home depot, and bought 2 big pieces of MDF wood. The square is 22” x 22”. I made a
Perimeter around the edges to raise the lid ¾”, to create more air space. The long pieces
coming off the lid will be resting on the edges of the trunk, to reduce stress on the fiberglass
bowl and to make it more stable when driving. I used gorilla glue’s wood glue.





I measured a hole for the speaker, and used a dremel to cut a nice hole in the MDF.





I was going to make a spacer so that I could lower the speaker into the lid more (with a lowered sub, the oscillation of the cone won’t go above the lid and I will be able to make a flat surface, as well as use it for trunk space).



versus:



To my luck, and surprise, Amazon had exactly what I was going to make!

[B 4 You]

Post 3
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Glued it onto the lid







Plenty of clearance above the speaker.



Stuck the box on top of the fiberglass to see how it lined up.





The masking tape around the edges shows the fiberglass that wasn’t necessary, and that was going to be trimmed.



After trimming with a jigsaw



Much cleaner fit



Time for glue! I thought about using more fiberglass resin, but gorilla glue seemed more practical, especially since it expands. The fiberglass was very bumpy and uneven.

[B 4 You]

Post 4
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Notice the edges on the lid have been raised another ¾”, because the amp was taller than the lid, and I didn’t want anything crushing it.





After the glue dried, I used a jigsaw to cut off the remaining fiberglass on the right side, as it was an eyesore. The amp will sit on the fiberglass platform to the left.



3 layers thick of ¾” MDF, making a total loss of vertical trunk space a mere 2 ¼”.



Time for carpet! I bought it off Amazon. The carpet was more flexible than I thought, it fit around each corner very nicely. I used a staple gun to secure it all into place.





All done! :]



The amp was bolted down from underneath the fiberglass. It was convenient to have holes in the amp large enough to fit a nut into.

[B 4 You]

Post 5
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I cut 4 small holes with a drill bit into the side of one of the lid lifters and ran the wire through there, into the sub. After the wiring was done, I put some glue around the wire holes to make sure it was air tight.





It sits very nice and snug into the spare tire well.



I punched the wire through the steering column grommet. (thanks Lookin4SVX)

http://www.subaru-svx.net/forum/showthread.php?t=54516

The link takes you to Lookin4SVX’s setup. You can see his wire much better than mine.



The 4AWG wire fit perfectly under the plastic door sill. The wire is under there in this picture, but you can’t see it.





From left to right: blue 4AWG ground wire; 18AWG REM cable; grey 4AWG power cable; speaker cable, remote cable.



Ground the amp by putting the battery terminal under the jack. the terminal is under the jack and around the long bolt that screws into the trunk, securely fastening it down.



Ground wire under the jack (hard to see).

[B 4 You]

Post 6
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I put the line-output converter inside the area by the rear taillight.



I ran all the wire to the left of the trunk and under the backseat.



The amp came with a remote gain knob, which fit perfectly snug into the ashtray. The wire going back to the amp goes through that tiny glass hole above the ashtray, and under the passenger door sill.





Everything still closes as it should.



I hooked the REM cable into pin 4 of the cell phone connector in the trunk. I also wanted a way to turn off the amp if I had the car running, just in case I wasn’t in the mood for the bass. I bought a mirror defogger/parking lamp switch from Gamesy and put it where the coin holder used to be. The left switch turns the amp on and off, and the right turns the iPod on and off.
(cell phone connector: http://www.subaru-svx.net/forum/show...88&postcount=9)





The iPod cord goes under the parking brake and plugs into the back of the cassette player where the OEM CD player would plug into. Can’t remember which pins we used, but there were only 5 of 13 used (left audio, right audio, switch positive, switch negative, ground). It was the same as the stereo for the early 90’s legacy’s. no SVX stereo schematics could be found.

[B 4 You]

Post 7
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Still have plenty of trunk space



The box sits just above the trunk ledge







80 amp fuse.



The power wire goes from the battery straight to the steering shaft grommet.

[B 4 You]

Post 8
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I still have a trunk!



I wired my amp to my subwoofer like this to achieve 2Ohms with its dual 4Ohm voice coils.





-Supplies used:
STAX 4000/1D Mono Amp
- http://www.poweracoustik.com/pa2006/..._amp_stax.html
Boss Audio NX10FD ONYX Subwoofer with dual 4Ohm voice coils
- http://www.bossaudio.com/main/1161
Power Wire: 4AWG Kolossus Fleks Kable by KnuKonceptz.com
- http://www.knukonceptz.com/productDe...?prodID=KFX4BK
Speaker Wire: 8AWG KLMX Kable by KnuKonceptz.com
- http://www.knukonceptz.com/productDe...prodID=KLMX8BL
Fuse Holder: DB Link – 4AWG Inline AGU Fuse Holder
- http://amzn.com/B000P0UBPE
Fuses: DB Link AGU80 80 Amp Gold AGU Fuses
- http://www.amazon.com/gp/product/B000P0W5A8
Carpet: Speaker Cabinet Carpet Covering Charcoal Yard 54" Wide (bought 2)
- http://www.amazon.com/gp/product/B0002ZPNK0
Battery Terminals: Monster 200 Crimpable Ring Terminals (4-gauge, 5/16" stud)
- http://www.amazon.com/gp/product/B000CIK9SS
Scosche LOC-80 Car Audio Adjustable Line-out Converter:
- http://amzn.com/B00009UHRE
RCA Cable: Klarity RCA cable by KnuKonceptz.com
- http://www.knukonceptz.com/productDe...odID=KLA-2M-BK
REM cable: Metra 40' Speaker Wire 18AWG
- http://amzn.com/B004H1MI2G
Spacer Ring: R/T - 10" PRO Woofer Spacer Ring 3/4" MDF
- http://www.amazon.com/gp/product/B004TAZ908
Gorilla Glue: (8 ounce)
- http://amzn.com/B0000223UV
Gorilla Glue Wood Glue: (8 ounce)
- http://amzn.com/B001E4E3KY
MDF wood from The Home Depot. (in-store)
Bondo fiberglass mat and resin and hardener from Advanced Auto Parts. (in-store)

-Websites used:
http://forum.edesignaudio.com/showth...wrx-72462.html
- alternate spare tire design.
http://www.i-club.com/forums/showthread.php?t=198934
- the bulk of my information.
http://www.ajquick.com/cars/tutorials/fiberglass.php
- if you’re new to fiberglassing (like I was).
And all the helpful people on www.subaru-svx.net :]
- thanks Gamesy for the switch.
-thanks svxcess for the wire recommendation.
-thanks Lookin4SVX for helping with punching the wire through.
-thanks to anyone else who chimed in :]

Dimensions:



i haven't measured, but other similar setups have achieved between .35 - .50 cubic feet of air space for these enclosures. i'm guessing i have around .40, which is what is recommended as a sealed enclosure for my particular subwoofer.

Hope you enjoyed :]

[kinz]

Nice write up. I like the planning you had and a functional clean finished product.
I had the same goal of adding bass without comprising trunk space. I just went a different route in completion.

[B 4 You]

thanks what did you end up doing for yours?

[Chuckls]

Where are the pictures of wiring the stock stereo and stuff? I'd LOVE to be able to use my iPod with it..

[icingdeath88]

Your way is much more legit than my way lol. There's a reason I have no pics of my sub anywhere, it's not the prettiest setup ever. The amps are just bolted in the spare tire well, and the sub is in a box that is bigger than it needs to be, but that is just the right size to wedge in between the top of the trunk and the bottom.

Very nicely done, sir. Would you leave the carpet over it all the time or no?

[kinz]

Super simple and easy. Amp and bass tube behind driver seat. Leaves no foot room for a passenger.

[B 4 You]

Where are the pictures of wiring the stock stereo and stuff? I'd LOVE to be able to use my iPod with it..

i didn't take any pictures of it, and i really don't want to unhook my whole stereo again.. does your car have a CD player in it? if it does, you'll have to sacrifice it. i literally spent about $5 on the entire iPod connection. all you need is a 13 pin DIN connector, a switch, and some wire. i'll ask my friend who helped me if he still has the schematics from it. like i said, it was very easy. one wire for left, one for right, one for positive, one for negative, and one for ground. it plugs in where the CD player goes, and when you turn the switch on, the cassette is fooled into thinking your ipod is the CD player. it has great quality, my stereo sounds better than new ones. (some new ones ) ten times better than a cassette tape adapter.

Your way is much more legit than my way lol. There's a reason I have no pics of my sub anywhere, it's not the prettiest setup ever. The amps are just bolted in the spare tire well, and the sub is in a box that is bigger than it needs to be, but that is just the right size to wedge in between the top of the trunk and the bottom.

Very nicely done, sir. Would you leave the carpet over it all the time or no?

why, thank you. i have the carpet smushed up behind the back seat for now, mostly because i keep showing it off to people. i'm going to experiment by putting it down. if it gets too hot, i'll just go buy some more of that speaker carpet. it matches our interior almost perfectly.

Super simple and easy. Amp and bass tube behind driver seat. Leaves no foot room for a passenger.

i love simple things. but i take people for rides occasionally, and it would bother the heck out of me to know something was on the floor. but that's just me.

[LastSVXintheChi]

yeah i have 2 amps screwed to the back of the back seats and a BIG tube with a 10inch sub inside in the trunk...no trunk space for anything but my tool box and a backpack!

yours is a much better setup