The Lotus Cars Community banner

1 - 12 of 12 Posts

·
Registered
Joined
·
1,208 Posts
Discussion Starter #1
Long story short, I'm going to be replacing the front clam because someone backed into it. I'm probably going to have some other things done (on my own dime) while the car is at the body shop (such as having a few scratches touched up, having the console repainted due to shoe scratches, etc.) and I was thinking about doing something with the back panel to incorporate a sub and then having it painted as well.

I've done fiberglass work before (worked for a Jet ski rental company in HS - repaired a lot of them) so I understand that there is a big difference between a patch up and a smooth finish job.

My thoughts were to take the back panel off, add some fiberglass to incorporate a sub (and possibly an amp), and then have them paint the whole thing while it is there. I've already got a JL 10 lying around, along with a pretty nice amp to power it. I would be willing to purchase an 8 if needed as I would like to form this to either go behind the passenger or driver's seat, but I will go in the middle if needed. I also thought about incorporating a mount for the V1 and leaving as much of the shelf as possible. I haven't taken any measurements yet, I just thought of this on my way to work.

1. Is it even possible to bond fiberglass to plastic? Is it hard?
2. Is it even remotely possible to get a sub to work behind either seat?
3. Would a sub sound like hell if I incorporated the Lotus plastic panel?

I don't need booming bass, I just want to go with something that has a little low end punch. We currently have the Kenwood enclosed sub (the 6inch built in amp one) shoehorned behind the passenger seat. It does OK, but I'd like a bit more.

If it helps, I've got Polk db651s in the rear with JL 5.25 XR's in the front. I think my wife blew one of the JL's, going to have to put my ear over there to know for sure...

Thoughts?
 

·
Registered
Joined
·
2,731 Posts
...three thoughts...

...first, there's not a lot of space between the back panel and the firewall, in fact so little that you'd have to exploit all of it to get anything close to a usable enclosure volume while maintaining the stock back panel profile...

...second, i've been told that the stock rear speaker locations just barely clear 50mm of mounting depth and they're already the furthest protruding portion of the back panel, so i suspect you'd have a nearly impossible task in finding a subwoofer shallow enough to mount within the stock back panel profile...

...third, you'd be losing all your insulation between the cabin and engine bay, which not only means that your equipment would get hot, but also that a stock back panel replacement enclosure mounted flush up against the firewall would become a very loud resonant chamber for engine noise to transmit acoustically through your driver...

...personally, i think chuck risen's package shelf enclosure (linked above) is just brilliant - it screws into the stock cargo net holes, requires negligible modification to your interior trim, doesn't consume any occupant space whatsoever, and looks cleaner than anything else i've seen to date...
 

·
Registered
Joined
·
86 Posts
Sorry, don't mean to be an ass, but do you buy an Elise to have a great sound system? Seems contrary to the purpose of a Lotus Elise.
 

·
Registered
Joined
·
1,208 Posts
Discussion Starter #5
Sorry, don't mean to be an ass, but do you buy an Elise to have a great sound system? Seems contrary to the purpose of a Lotus Elise.
I agree. But the car is going in for painting anyways, I've got a spare JL and amp in the closet, and I like to do squirrely stuff like that.

I'm not a good enough driver to care about the extra 10-20 pounds and if I was, I'd simply remove the panel at the track.

In any case, we DD the car, so some nice sound is a bonus.
 

·
Registered
Joined
·
2,731 Posts
Sorry, don't mean to be an ass, but do you buy an Elise to have a great sound system? Seems contrary to the purpose of a Lotus Elise.
...superb handling accompanied by engaging music makes for a glorious daily driving experience...

...considering lotus' full line, i posit that the basic elise is clearly intended as the platform's touring model - and honestly, ten to twenty pounds won't significantly compromise performance if it isn't being raced competitively, while the stock stereo can be unlistenably anemic at times...
 

·
Registered
Joined
·
2,923 Posts
FWIW, JL Audio has a new subwoofer out that only requires a mounting depth of 2.5 in. But I think in order for this to work properly, you would need to fiberglass some sort of enclosure to create a sealed cavity on the back side of the panel. You might need an offset ring to compensate for any clearance issues.



In regards to losing the all the foam insulation between the panel and the firewall, that is how base Elises (no touring) are spec'ed, and how I ordered my car. While it is louder, it is not as catastrophic as ...m... has described it in his third point. There's simply not enough material or sufficient sealing to set up a resonant cavity. (No offense, m.)

JL Audio also has released a new amp in 4x150 and 1x750 W configurations that is less than 2" thin. It's footprint in the other dimensions is about less than a sheet of paper (8.5x11).

 

·
Premium Member
Joined
·
92 Posts
I installed a 10" Morel sub and had a custom carbon fiber enclosure built for it. It's mounted nicely between the seats on the little shelf and is secured using the 2 original mounting holes/screws for the little storage net. It looks like it was OEM and sounds great! I thought about putting 2 - 6.5" subs in the same space, but they barely fit side-by-side and the enclosure was not going to be adequate for 2 subs.

I'll post pics when I get back home in a couple of days.
 

·
Registered
Joined
·
2,731 Posts
...i'd love to see pictures - please do!..

...i considered morel drivers, but they all looked pretty deep on the specification sheets...
 

·
Registered
Joined
·
2,731 Posts
In regards to losing the all the foam insulation between the panel and the firewall, that is how base Elises (no touring) are spec'ed, and how I ordered my car. While it is louder, it is not as catastrophic as ...m... has described it in his third point. There's simply not enough material or sufficient sealing to set up a resonant cavity.
...using the stock plastic panel and bare firewall as each half of the enclosure, i think you're right...i was thinking more along the lines of replacing the entire back panel outright with a sealed fiberglass enclosure of matching profile, which i suspect absent of insulation would transmit coupled firewall vibrations similarly to a drum shell - very loud and ringy...
 

·
Registered
Joined
·
1,208 Posts
Discussion Starter #11
I installed a 10" Morel sub and had a custom carbon fiber enclosure built for it. It's mounted nicely between the seats on the little shelf and is secured using the 2 original mounting holes/screws for the little storage net. It looks like it was OEM and sounds great! I thought about putting 2 - 6.5" subs in the same space, but they barely fit side-by-side and the enclosure was not going to be adequate for 2 subs.

I'll post pics when I get back home in a couple of days.
Would also love to see pictures.
 
1 - 12 of 12 Posts
Top