View Full Version : First time fiberglass project

02-09-2009, 10:36 AM
Hey guys, I am wanting to build put subs in the trunk of a 2003 cavalier coupe.

I want the enclousers to be in the corners, one on each side, by the tail lights. (boxes should be built to be easily removed for easy access to change bulbs)
I need to use as much space possible to achieve the 2.25 sqft w 25sq port area tuned to 36hz per sub. all glassed into the sidepanel area of trunk. My question is calculating the sqft of this box, since wont be a sqrd box.

I also am building an amp rack under the rear deck, or if permitted, I could mount the amps on the new boxes to keep the flip down seat passage from being obstructed. I will be closing off the rear deck speakers with foam baffle and spraying the underside with spray-on deadening. All will be applied to the inner panel area before final box fastening. Once this is all complete the final skin of the box will be RVINYL wrap, CarbonfiberII style. with new gray carpet in the trunk.

To me this sound simple, but I never done glass before so I am open for suggestions.

2 = T5-12 Soundstream
2 = SST6.9 Soundstream
2 = SST4.6 Soundstream
1 = XTA360.4 Soundstream
1 = XTA360.2 Soundstream
1 = A3000DB Power Aucustik

02-09-2009, 11:54 AM
the only way to find out how much airspace you have is to build it first and then fill a 1cf box with packaging peanuts. each time you dump a full box it will be 1cf. due to the odd shapes, curves and lines of corner boxes there really is no other way to do it. my suggestion would be to build it bigger than you think you need as you can always add pieces of 2x4 or similar material to take away airspace.

tuning a corner box like that is going to be just as difficult. check out www.fiberglassforums.com and you should be able to find all the info you need by searching the forums.

02-09-2009, 12:03 PM
I'd do a quarter circle for your boxes, easy to calculate volume, removable, simple build.

02-09-2009, 01:35 PM
Well, I thought about starting with the port. Configuring it for a specific shape and then if needed having it extend into the box for desired fq response. Sort of like a slot port, And I think I will make the box bigger than needed because I still have to account for the displacement of the sub. So on that note, I will gut the trunk and line the whole thing with plasitc, and wax coat it?, then start glassing the interior forms and building it out from there. It says the displacment is .12 cu ft. and the woffer wieghts 32lbs, so I need to make it a lil thick.

02-09-2009, 02:07 PM
put down a good layer of blue or green painters tape over the area to be glassed. cover that with a layer of tinfoil. put 2-3 coats of wax on that (any kind will do, i use whatever paste car wax is cheapest). then lay down your first layer of mat and resin. lay at least 3-4 layers in the car so that it will hold it's shape when removed to cure.

as far as strength, you should make your box thick enough so that you can stand on it with NO flexing at all on any side.

again, go to the site i posted and you will get all the knowledge you need.

02-11-2009, 08:05 PM
what to buy, tell me what to buy, not sure