Question about Car speaker design.

I spend 4 hours a day in my car minimum. I don't buy new, since I wear the things out at the 45-60,000 mile per year rate. I find low mile older cars cheap and quickly rack up the miles. The latest "cream puff" for me is a 94 Cutlass Ciera, right from Grandma.

I have a nice Alpine in the dash with pretty green lights. A set of 3.5" Pyles and sep. tweeters bi-amped with a rather pricey crossover have made the front very listenable.
The 6X9's in the rear are not acceptable. Even after trying many different options. I find they provide "boom"...but to call what comes from them "bass" would be wrong.

I have 5 different sets of drivers lying around. The 4" Fostex I have been playing with and the 3,4 and 5" Stillwaters.
Since the Auto market seems to be dominated by the "neon-glow-blow-your-body-gaskets-SPL "competition" mentality, I have not found anything in two weeks of searching that can fit the bill.

There are a ton of sites with info on the 4" fostex for example. But none of these designs will fit in a car.
I am looking for something that I can fit into the rear deck of the Olds. Even PVC designs would be OK, cause I don't mind hacking the rear deck up...but it needs to fit in the less than 24" tall space that GM has allowed me to work with.

Anyone built thier own system for the rear deck of a car?

Any enclosure ideas?

Helpful sites?
Try there is a helpful forum section there. Also being in the business we call those Olds cutlass cierra's "The Nun" :) Happy motoring. ~Tim
Sounds like subwoofer time. I'd say 10 inch drivers in a box with the 6X9's removed should do the trick. Check out and submit your questions to their subwoofer forum section. Mention that you want sound quality instead of just SPL and they will answer regarding box size, crossover points, power needed etc.
Gumby, if you want to use the 4" Fostex, you can use that design that I posted awhile back, that uses the 4" PVC pipe as a T-Line. You can mount the "heads"( 90 degree "L" bends) right on your rear deck, with the speaker facing forwards, and use short sections of 4" pipe under the rear deck with bends connecting them to equal the 5 foot length you need, and bring the outlet of the port back up through the rear deck lid again. You could do this on both sides, and most of the pipe will be hidden under the deck. This T-Line is good down to the low 40's with the FE-103. SPL is limited, but sound is good. Also, price is cheap. No woodworking, and easy assembly. A small handful of pink insulation behind the driver is all the stuffing you need. Probably sound pretty good in a car, with the small area. Midrange peak can be tamed with a little "doping" of the paper cones. But, too much will cut the highs. Do one coat at a time, and listen each time. Cheap and easy,and should fit in your space requirements. Sounds like a plan. Why, because you're Gumby dammit! And a bendable plastic figure needs to have a bendable plastic speaker enclosure.
Thanks for the info folks.
I will let you know how things work out.
I DO like the idea of flexi-speakers :>)
The "Nun"???????????? :>)

Please explain.
wrong wrong wrong!!
you need to speak to kirk neal from ampman audio.
you need rainbow reference or A/D or JM Labs speakers
with a monitor one amp
if you like your alpine that much ...keep it
personally, i would change the head unit to a Eclipse/nakamichi/denon
Gumby, what is it you are trying to accomplish with the rear speakers? Do ya want good bass or good bass with rear fill?

I got outa the car audio biz afew years back and have forgotten more than I remember but I do recall that there were very few drivers made that could produce any kind of realistic bass when loading was by means of the trunk.

Decent bass is much easier to obtain using an enclosure of some kind, be it sealed, vented, isobarik or what have you. By using the trunk as the enclosure your basically running the driver in freeair.

There are drivers specifically made for this application, but most of those are poorly designed.

I have heard a few systems considered high end in the auto world. I heard tight bass on the bottom end... but a huge hole between the midbass drivers and the subs. I have to fill that hole or I wont be happy. I need midbass.
I would even try "boxing" a good set of 6X9's under the deck.
I am waiting for the info on the right size for a sealed box for the 5.5" and 4" Stillwater drivers I have. This might solve the whole problem. I don't know.
I tried some stuff with the Fostex drivers I have been playing with. Not enough beef to overcome road noise.

The 3.5" in the dash have a 60 WPC amp crossed over @ 120, with great results. (Boatload of headroom) :)
If I could just get 200 and down dealt with, I would be a happy man.

I will say this however. My screwdrivers and soldering iron have been getting a fair amount of use and I am having more fun with this car project than I have had in years.
So much room for tweaking :)