As a stop-gap before gutting my new (2010) clubman, I'm installing a subwoofer in the spare tire well and running it off the rear channels. This is way less than ideal but should work well until my wife decides whether or not she wants the clubby as her daily driver - in which case I'm keeping all the good stuff for my next project.

I'll be using the tire well itself as the enclosure. Ghetto for sure but it beats fiberglass for ease and volume (ft3, not necessarily DB).

 

Pictures aren't showing up yet. I'll see if I can sort that out on lunch.

Anyway, it's a 1.5" MDF baffle. The top layer mirrors the tire well cover board. The lower layer matches the tire well as traced from the foam tool-holder insert. Two 2" ID, 7.5" long ports are installed which should make for a 37-40 Hz fb. This is higher than I'd tune most boxes but with an Alpine type R 10 with 20mm of Xmas and only 25-40 watts rms, I'm not concerned about blowing anything up below the tuning frequency. Besides, the clubman has crazy cabin gain. I had a 32hz fb set up in my cooper and it was annoying. I imagine there were 50db of gain at that frequency.

 

Test fitting the baffle

 

Deadened the hell out of the tire well. Several layers of CLD, 3 pounds of duct seal and a layer of poly batting and MLV on the bottom to hopefully reduce the

road noise being transmitted through the port.
Heavily deadened tire well

 

Removed the right rear interior piece to expose and remove the HK amp this morning. Partially disassembled the connector and removed pins 13, 21, 31, and 32 for the rear tweeters.
The rear woofers are run off pins 3, 4, 22, and 23. When the connector is disassembled, it becomes two connectors. In each of those halves are a larger red and a brown wire. Those are the wires you're looking for. Cut the harness and ran a length of wire to the passive crossovers, each of which will power one voice coil of the dual voice coil subwoofer. It will only run at half power, since the amp is expecting a 2 ohm load, but it should be plenty of power and the amp will run cooler as a result - especially with the tweeters entirely disconnected. Crossovers are simply velcroed to the body.




Initial amp-to-Crossocer wiring.

 

Well, it's finished but it's lame. The install looks great but the HK amp clearly has a high pass crossover in place. I'm getting about 1 watt under 80 hz but there probably next to nothing from 40 down :-(

 

I hooked the sub up to a separate amplifier this morning to run some tests. The tuning frequency is spot on 40 hz and it pounds pretty seriously for "just a ten". There's some port chuffing at higher power levels, around the tuning frequency, but it's only really apparent when using test tones; not so much with music.

Anyway, I switched the left front and rear channels and am running the subwoofer off what was the left front. Unfortunately, without added power, there's only a little more sub-bass available since the amplifier makes pretty sharp cuts below about 60 Hz. I did pick up a few DB there though.

I'm considering a line out converter but there's no place to grab a full-range signal so I'll probably be stripping everything before then.

*If you're ok with the HK system and just want more bass that takes up zero cargo space, I recommend this route. You should definitely run a separate amp and LOC but even still it shouldn't cost you more than about $300. I have about $150 in this since I had most of the building/finishing materials on hand already.

 

My line out converter came in today. I'm running an old lepai 2020+ amp to them, plugged into the rear 12v socket :-P

At probably 25 total watts and anything approaching half gain on the LOC, it's WAY too loud! I'll probably extend the ports to lower the tuning frequency and settle the ripple/hump at 40 hz. I'll address the port chuffing at that time as well (which I can't hear over every damn body panel resonating). It slams. Turning the gain way down... once I'm done having fun with it!

 

Testing different tuning frequencies :-)

 

I guess its a matter of what you want. I have compact spare tire, slime pump, toolkit and jumper cables in my wheel well. And I use the back area to throw all sorts of things that would destroy the area. No one has ever had good luck tuning the two 6x9 woofers in the side walls?

 

I did, in my R56. Even still, the potential here massively exceeds what's possible with two 6x9 woofers. The clubman sides are assymetrical with the club door being too tight to make a decent enclosure from anyway.

Once I finish the grills for the ports and woofer, they will be relatively indestructible. But of course, it depends on what you want. If you don't want sub bass and want to **** on people's projects because you need a spare tire, by all means get your post count up.

 

Well, duh, a huge woofer in a tuned port would of course spank 2 6x9s. But YOUR TITLE to the post was misleading. It does not take up no space, it takes up very valuable space to me and I'm sure others. I didn't poop on your thread at all, just pointed out it's a matter of priority and adked a simple question as to the effectiveness of tuning the actaul no space taken 6x9s. Sorry if you are thin skinned.

 

Anyone know the most convenient place to tap for full range signal with the HK system and if the signal will be high or low?

I want to add an amp/sub and leave all the other speakers untouched.

Can I do this from the rear or do i need to tap signal wires in the front? Will I need to line covert to low, or is there an RCA level full range?

I've looked on Integral audio, but the sub install manual does not exist. Incidentally, I'm putting in an Integral Audio box I bought used, but I don't have access to instructions. I'll be using my own amp/wiring. I've emailed IA asking. Hopefully they will respond.

 

The easiest place is off the HK amp in the right rear. A line out converter fits there nicely.

 

It takes up no space. I need no spare. Also, no, not duh, my two 6x9s were installed in purpose-built ported enclosures and outperformed two Alpine type R 12s in sealed enclosures. Go away.

 

The finished product.
I broke down and installed an amplifier - a cheap Rockford class D rated at 612 watts RMS. All told, the budget was blown and I spent nearly $400 on everything. No regrets. Now this thing is viscous and spends most of its life with the remote level control set around 20%. Ultimately, I lowered the port tuning to 32 Hz and added some eq from the amp at 45 Hz. I've throw strollers, groceries, etc on top of this sucker for over a month now. No problems, no audible port noise, no space requirements, just bass.