Prolly just some camo fabric. I always go to Jo-Annes Fabrics and get some felt since its pretty close to the actualy carpet they use and very easy and manageable to get rid of all the seam lines. Ill see if i have any pics of my old one. First i had an orion hcca 12.2 in a band pass with a power acoustik 2200w amp and then i had two alpine type x's in a ported box ran off the same amp, both boxes were mdf and fit in my trunk but not custom to my car. I did build a couple of fiberglass boxes to mount the subs behind the tail lights, not the loudest, but definitely the cleanest sound and got rid of that anoying trunk rattle.
Once my turbo project is done then ill be putting in a singe Fi BTL N3(3000w rms) or two of them(6000w rms) ran off corresponding hifonics amp. And if i ever can get a hold of rear seats with a foold down middle arm rest i can make a ported box with the port being right behind the armrest and the same size as the hole.
Bbron: can i ask why your opting for 4 subs instead of 2 that can produce them same amount of base?
that sounds awsome! im kind of doing somthing similar. I have 2 of my subs mounted on the back seat in a sealed box and 2 in a ported box in the trunk facing towards the opening into the car. i may move my amp and add a third sub on the back seat. I love fi and was going to get a few of those, but this deal fell in my lap, which is y i have the alpines
I'm rocking a pioneer CD deck with a USB hook up for my iPhone
Polk Audio 180w 6" speakers in the front door
Pioneer Audio 6x8 Speakers in the back (yes 6x8 no not 6x9)
A few years ago I was running:
Pioneer CD deck
Kicker Audio 6.5 speakers in the front
6" Polk Audio 180w Speakers in the rear (now relocated to front)
2 12" JL Audio 12vW0 subs
Kicker 300w Amp
all wired with Tsunami Sub to Amp wiring kit
enclosed in a MTX 2 port sealed box
system with a custom built wall
old rear deck set up ( same speakers just moved to the front)
the old pioneer deck (was stolen)
next up I'm planning on revamping the system again, possibly all new speakers reverting back to 6" speakers and possibly a new sub and amp set up, this time only 1 single sub, 2 was too much.
i like the clean look of the jls! im currently re doing mine again... after i just got it in! i need more bass! it was loud enough to have rain jump off my windshield, but i could still inhale haha so... re designing 2 boxes and wiring and larger ports, hopefuly guna hit 150db!
Come spring I may try to do the Scoobymods.com 10" sub install in my coupe. If you've never seen it, you mount a 10" behind the armrest/doorcard in a coupe. There's a large enough opening in the body to mount it behind the panel with some pressboard. After it's mounted you trim the back of the doorcard so it acts as a grill to protect the speaker. It seems that scoobymods is down so I can't get a link to the install.