I put a Bose RSX spare tire subwoofer in my car and wanted to share. The end result is a small hidden subwoofer that helps with bass but doesn't rattle the car to hell. It fits in the spare tire and raises up the rear mat less than an inch, so it's hard to tell its there.

Note: I have not test fitted the spare yet for its intended purpose, but will next time I have the car up in the air. It looks like it should fit fine but still need to check. It fits perfectly in the spare tire well though.

Here are some pictures. (Don't mind the wiring, I need to clean it up)




Here is what I used:
RSX Bose Spare Tire subwoofer
Honda Fit 4x100 spare tire (T125/70D15)
Generic relay (4 post)
Power wire w/ inline fuse (15A), Ground wire (12GA should be fine)
22uF capacitor
RCA signal wire

The bottom tip of the subwoofer that goes into the center of the spare tire needs to be cut about 1", which will expose the sub chamber. I filled that with silicone sealant and let it dry. To fit properly into the tire center, the circumference of the sub's bottom tip will also need to be ground down - I ground it down until it could be pushed in without much effort.

I won't go into detail on the wiring, but the RSX sub will need a relay to power on/off, otherwise it will be on all the time. I used the amp power-on wire from my head unit to trigger the relay. The power / signal wires on the subwoofer harness were pretty obvious but I don't recall the colors right now.

The signal cable I used takes R/L audio from the RCA outs of my head unit and combines them. Depending on your head-unit, you may get a POP from the subwoofer on station changes or other actions. The 22uF capacitor inline with the positive signal wire will help with that, with it inline I only get a POP when it turns off.

 

Neat setup. My trunk leaks water probably from the hinges or some **** so I wouldn't risk doing this lol.

What's the silver stuff lying around? Insulation/noise damper?

 

That's dynamat that one of the previous owners slathered the car in. I don't care for it but it's hard to remove and is hidden for the most part.

Also: The Fit spare tire almost cleared my front brakes ( Fast brakes 11" w/ integra calipers), it would fit the rear just fine so I'm no worse off with it.

 

this is a great idea

good job for thinking outside the box ^_-