Quick background: I just replaced most of my 2004 996TT Cab audio components (Kenwood H/U, Focal Evo 3-way speakers in door and dash). While I appreciate having Bluetooth and a back-up camera, not loving the sound as much as my wallet is telling I should be. I know it's a cab and the sound won't be winning any awards, but I'm still hoping to improve it. Which brings up the much lamented subwoofer conundrum and my question...

After doing quite a bit of searching and forum diving, I didn't see anyone who tried to reuse/repurpose the factory Bose enclosure in the passenger foot area. The stock speaker is 4x6 that points down. Is there anything that would prevent me from using the same enclosure by covering up the existing speaker and port holes, and cutting an opening for an 8inch woofer that would point out towards the passengers feet (see pic; paper represents speaker size)? The enclosure is shaped a bit like a parallelogram. Taking some basic W / L / H measurements, the enclosed volume is roughly 0.29 cubic ft. Most of the shallow-mount 8in subwoofers I've researched on Crutchfield require a minimum of 0.2 cubic ft. (sealed), so while not ideal, I should be within specs.


What am I missing? Thank you very much for your thoughts!!!
Stock (ported) enclosure

Hypothetical 8" speaker facing outward (sealed)

 

Polyfill it seal it correctly and dont expect too much.

 

I am VERY happy with the Bill Jehle cab box. It was like $400 and is sturdy AF. It's a tank! (In a good way) takes up only slightly more foot room than stock. I've had it for over 4 years. Comes in raw fiberglass - had it recovered with a stock looking black carpet matches my interior perfectly.

https://billjehle.com/PORSCHE/HTML/console-front.html

 

Thanks for the link. Any idea how large the enclosure is (sqft)? I didn't see it listed on the website. It looks pretty close to size of the stock unit.

 

Nah. I thought about filling it with sand to measure the volume but said "eff it" and just installed it. It whams. Regardless, its gonna be a million times better than repurposing the stock box would be.

Search the forums for reviews on it. That's how I found it.

Like I said above, it's slightly larger than stock but not by a ton. Foot room is compromised there anyway! It's either this, or the behind the seat ones by CAI (I think).

I can shoot pics of my install tomorrow if you want. You can also call/text me. Send me a PM if you want.

 

I was worried about legroom so I went with replacing the rear sub instead - this doesn't compromise any passenger comfort but still gets the job done nicely...

 

I dont think that works in a cab... lol

 

Oooops!

 

No worries, I was just curious.... I have the yellow/mustard interior, which has been kind of hard to find extra carpet for which I'll need for the custom box. I was either trying to do it on the cheap(ish), get a little out of it sound-wise and reuse the stock enclosure or install a proper 10" or 12" where the spare tire is (which there is also a curious lack of forum posts about. That is a completely different route which poses different problems...)

I'm half tempted to buy another enclosure off of ebay for $150 to see how well it can be sealed and tuned. If I learn it's worth it, then go ahead with with Plan A. If it sounds like crap or can't get enough sound from it, then I'm only out $150.

Thanks again for info though.

 

pancing... would you recommend using both dynomat and polyfill?

 

I spent a bunch of time on this as well. On the "other" forum area few re-uses including an 8" shallow in the existing enclosure with no external changes. Almost all of the aftermarket boxes take up space and are very apparent. I prefer the fact you can't tell where the stock sub is. I retained the stock speaker and added 2 removeable 8" powered subs with quick-disconnect connectors which sit in the rear floor. The wiring runs under the console and ends in 2 connectors at the rear of the console.
I added these when I redid my stereo last year. Started out as just a HU but I ended changing everything except the speaker wiring. It is now an iPad mini2, Pioneer DEH-80PRS, JBL MS-8 surround processor, Kenwood 5ch amp, (4) JBL 329s, 2 Kicker ksc650s and 2 JBL BassPro 8" subs. Subs are black on black rear floor mats so they blend in, are removable and everything else fits where stock did. The MS-8 handles most of the tuning in terms of what speakers are where. The stock sub plus the 2 JBLs brings a lot of sound for what will reasonably fit in this car.

 

Here is a link to another forum (don't know if if you can do that) that shows a guy modding the stock cab sub enclosure for an 8" shallow speaker.

https://rennlist.com/forums/997-foru...r-upgrade.html

 

If you don't use the driver's backseat you could try something like this out. I love it.

 

yup pretty much what I did built a nice box with a 12" woofer, drive it with JL 750.1 works great no issues (did the passenger rear seat area for mine) then just replaced the remaining 6 speakers with aftermarket JL 600.4, bam done

 

I built a custom box which sits on top of my (folded down) rear seats. Box is held in place by straps and the wind deflector which goes over it. Rock solid and easily reversible. Put a huge 10" Pioneer woofer in it, which fires down on the folded seats. I refuse to pay 400$+ for a stupid subwoofer box.