Rear hatch speaker box
 

Well here is your updates guys. Many have promised a 8" rear hatch box and given months of time with no results, I did it in 2 days. Thanks to Max who sent me very complex and detailed dimensions I made a ruff MDF/ fiberglass box. The pic you will see is only of the ruff box no fiberglass as I just desided to bust out the jigsaw since its 25 degrees outside. I will not be mass producing these (sorry) as I do not have the time. I may make few for friends. Once I make the final cuts on my table saw and do the fiberglassing, I will make all the measurements avaliable to those who want them. Mind you that you will need skills in fiberglassing to finish this project. The only modifications are that you bend up the vanity cover bracket up to allow the box to slide in, then bend it back dow as it will hold the box in. The other is that you need to pull in the license plate wire 1" as the box sits right on top of it. The box can only take a 8" sub with a max depth of 5". I will get internal cuft dimensions after it is done
http://memimage.cardomain.net/member...9_392_full.jpg
http://memimage.cardomain.net/member...9_389_full.jpg

why all of the headaches?
 

I have explained this to several members before, but I guess nobody was willing to try it, all you need to do is buy the fopllowing...

2 garbage trash bags,
1 can of expanding foam
1 roll of duct tape (use the expensive type)
a rasp,
a long bladed brad knife
3/4"mdf about 2' x2' in size
1 tube silicone sealer
and fiberglass.....

place trash bags back in void in front of tail lights, fill with expanding foam, tie off.

bag will expand with foam until it takes shape of void, wait until hardened, takes a day or two.

use long bread knife to trim top of now hardened expanding foam and plastic trash bag so that you can slide it out (may need to trim other areas as well) trim forward facing section flat so that you can trim MDF to fit as front cover/speaker baffle

use rasp to remove approximately 1/4" from all dimensionson now hardened foam. use rasp to rough up MDF so FRP and foam will stick to it.

use 1/4 tube of silicone sealer to glue MDF baffle to front of foam.

cover or wrap entire piece or foam neatly with duct tape DO NOT COVER MDF PORTIONS.

cut, trim fiberglass mat, apply over the outside of mold x 2 layers. let harden cut speaker hole in MDF front baffle, reach through and scrape out all of the foam (PITA part).

you have now made a fiberglass sealed enclosure that fits exactly into the void in front of the tail lights, you may now carpet the front to match the interior, or easiest is to just let the stock carpet hang down and cover it all for a totaly stealth look.

ken

I like it john, simple yet it works.

Ken your approach sounds pretty cool too. Did you make a enclosure for the back, if so do you have any pics?

background: I used to run a stereo custom car shop back in the early to late nineties, when custom stereo meant more than a cheap as best buy amp and some garbage speakers......

current, I curretnly have a 1997 12" cerwin vega stroker (NIB) that I installed in the seven, so while it is in a FRP box, it does not fit in the back like that, though I lately for weight reasons have considered pulling it and replacing it with two of the square 8" solobarics mounted in the back.

If I do I will take photos and post them.

cheers

kenn

Hey Ken -

What's MDF? And FRP?

Thanks,
Rich

im one of your friends youll be making one for....right? :D

Sorry, they are acronyms for Medium Density Fiberboard, MDF (what you make boxes with) and FRP Fiberglass Re-inforced Plastic (fiberglass)

same stuff you always use for any stereo work, and the FRP is the same as you use for doing body repairs on fiberglasss parts.

If I lived in the states still I would have started mass production of stereo products for all three gens of the RX-7, but with living in Japan, the cost of shipping, and the cost of raw materials here it would not be cost effective.

not sure waht MDF runs in the states anymore but back in the 90's it ran about 15~20$ for a 4x8 sheet of 3/4" over here it runs 40$ for the same thickness in a 3x6 sheet. and do not even mention FRP over here a gallon can of resein costs about 75$ then you have the cloth itself at about 15 bucks a meter. So it would be fairly expensive to make and ship

figure 1/3 sheet (3/6 sheet) of MDF for the front baffles and about 1.5 gallons of resein and about 2 meter of cloth per two speaker boxes. so to make two complete sets (hand made not production molded) would honestly run about 150.00 per set of two without shipping.

now if I was going to run these production style then I would need to make two reverse molds, one for each side, and they would be good for about 10 castings each before they degraded past the point of use. it would cost slightly more but would cust down on needed supplies over thelong run.

just not worth it when you consider shipping to the states would proabaly run about 70~80 per pair.....

but if someone were to do this in the states, then the material costs would be much lower, (almost half) and the shipping would be negligible.

yeah I thought about it a while back when $100T2 was trying this out, but the costs would be too prohibitive for most of the members.

kenn

I tried the plastic bag thing, and the expanding foam I used wouldn't stick to the walls. About half of it never even dried. I don't know what I did wrong.

I saw this today. http://toolmonger.com/2008/01/24/fro...wer/#more-8685 would make it a hell of alot easier to spray a even layer of foam to make a mold.