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ThatA4T
10-13-2009, 11:13 PM
ive seen the diy on how to do the custom fiberglass sub box on the left side of the trunk but has anyone ever made one for the right side as well? how do these boxes sound? it seems like they wont have enough volume to create loud bump... i may be wrong so any incite would be greatly appreciated

biketsai
10-13-2009, 11:18 PM
The right side doesnt seem to have as much room from the preexisting hole. Supposedly those setups are just not as solid and wont "bump" as hard, although I wouldnt mind having one there.

ThatA4T
10-13-2009, 11:20 PM
damn i really wanna do 2 10's or 12's in my car while still keeping most of my trunk space for all the snowboarding gear... any recommendations?

BreakMyWallet
10-13-2009, 11:27 PM
its all about how big you make it though. you can definitely get some bump out of it.itll be more efficient if you take out the panel and start the FG on the actual metal. youll get a little more room. then make some custom side panels to cover off the rest of the trunk (towards the cabin).

i would make em for people. but i got enough work to do on my own ride. LOL

ThatA4T
10-13-2009, 11:31 PM
haha well my dad has a 1000 square foot cabinet shop at my house with every wood tool imaginable and he can do anything with wood. i havent done fiberglass work before but it seems easy enough... and im incredible picky so i will keep trying till i get it perfect! this is a future project but i was hoping to find someone with some experience in this field

GR-RALLYE
10-13-2009, 11:46 PM
haha well my dad has a 1000 square foot cabinet shop at my house with every wood tool imaginable and he can do anything with wood. i havent done fiberglass work before but it seems easy enough... and im incredible picky so i will keep trying till i get it perfect! this is a future project but i was hoping to find someone with some experience in this field

it all depends on what type of sub you have and what kind of box it will be (vented ported sealed), I'd figure that out first then measure some dimensions and see if you can fit a enclosure there

ThatA4T
10-13-2009, 11:49 PM
well my original plan was to do either 2 mtx 8500's or 2 alpine typr x's either 10's or 12's i like the sound of both... 10's seem more reasonable. i also want to do ported but sealed would work too if anyone has any good ideas. i want it to sound clean and loud.

josmo
10-13-2009, 11:55 PM
i dont see a need for that serious of a sub unless your going to dynomat the entire car and get ride of every rattle. I have to type r 10's and they punch pretty hard with little wattage. I save the money for mods

ThatA4T
10-13-2009, 11:59 PM
i plan on doing a ton of dynomat. ill do the whole trunk when i do this custom setup as well as the roof when i do my headliner and all the doors when replacing the speakers. i dont plan on doing everything at once but in the end i want a very loud clean system.

audizz a4
10-14-2009, 01:10 AM
Sorry to jack thread but i have another thought, Along the 10 inch on the sbwoofer enclosure the trunk because I too snowboard alot and use my trunk, foldeble seats alot!
I don't use my full size spare so it outs of the car and it saves weigt. Has anyone built a sub enclosed with a quality sound Inisde of the wheel cmpartment? I would Kirk to fit a quaality 10 pr a clear. 12 in the. And for protections maybe create a gaurd around it.

ThatA4T
10-14-2009, 01:15 AM
in my case i really dont want to loose the spare haha it seems like i have seen something like that somewhere. i dont see why it wouldnt work

goody6691
10-14-2009, 06:04 AM
Sorry to jack thread but i have another thought, Along the 10 inch on the sbwoofer enclosure the trunk because I too snowboard alot and use my trunk, foldeble seats alot!
I don't use my full size spare so it outs of the car and it saves weigt. Has anyone built a sub enclosed with a quality sound Inisde of the wheel cmpartment? I would Kirk to fit a quaality 10 pr a clear. 12 in the. And for protections maybe create a gaurd around it.



i did this exact thing. fiberglassed the spare well, 2 memphis 10's in the well and a 5 channel amp further up in the trunk floor. the entire trunk has a false floor that raised the floor height by around 2 in's. i got to spare 1x1 trim wood and made frames around the subs and amp and stapled it to the oe trunk mat. now it can lay it over my gear and i can still carry stuff without fear or damaging my stuff. sounds pretty good too.

ThatA4T
10-14-2009, 10:06 AM
do u have pictures?

hiwords1
10-14-2009, 10:12 AM
JL made a stealth box that you mount under the rear deck. that would be the best bet if you wanted to save as much trunk space as possible.

ThatA4T
10-14-2009, 10:16 AM
ive seen that box but i have a two problems with it!
1) cant find it anywhere haha they dont make it anymore
2) it gets rid of the rear deck speakers

if anyone has one of these theyd be willing to sell please let me know i would want one but i would need to urgrade all of my other speakers first since it gets rid of the 2 on the shelf

TighTT
10-14-2009, 11:53 AM
ive seen that box but i have a two problems with it!
1) cant find it anywhere haha they dont make it anymore
2) it gets rid of the rear deck speakers

if anyone has one of these theyd be willing to sell please let me know i would want one but i would need to urgrade all of my other speakers first since it gets rid of the 2 on the shelf

I run a stealth box and have 2 JL's installed on the deck in the OEM spot. There is even an opening in the stealthbox for the POS OEM amp to fit in.

ThatA4T
10-14-2009, 11:56 AM
damn i want one of these where did u get it and what size subs does it use? i want at least 10's maybe ill have to make my own stealth box

somebody5788
10-14-2009, 12:23 PM
I've been considering doing a similar stealth box. I want to do that as well as something similar to what I saw in a Boxter S w/ a bose system. It had the little acoustic opening between the headrests. I think that would be really neat in between the rear headrests lol w/ a little raised rear deck.

Oceanside
10-14-2009, 01:17 PM
Has anyone done and open air in rear deck design yet? maybe 8's or one 10?

Quattro 4 Life
10-14-2009, 02:29 PM
I had something similar to this. When i bought my car the previous owner had a custom installation box installed along the right side of the trunk. The entire car was outfitted with soundstream products including a 5 way amp for the speakers and sub. The only thing that wasn't soundstream was the sub driver itself. The box stood out from the right side about 6in from the flat part in the middle of the trunk on the right. It held the amp and driver and was a closed box with that foam cloth stuff packed inside. It worked out alright but you cant fit golf clubs in there with a design like that.

I ended up selling it and getting JL. some local S4 guy ended up with it. I wish i didn't lose the pictures i had of it, it was very well done. They also drilled into the floor deck to mount it. they didn't hit the gas tank some how??[confused] still not sure how that happened

Calabria
10-14-2009, 11:35 PM
I just have a Huge ported box in the back, carpet on the box matches the OEM carpet pretty closely...want to sell it.

onemoremile
10-15-2009, 04:35 AM
Let me know when you guys have questions on this stuff. I'll try to answer them all but remind me if I miss one here or there.

Box size is not directly correlated to bump. The size is determined by the TS (Thiele Small) parameters. These parameters describe numerically how the sub works electrically, and physically. The Vas and Q (electrical, mechanical, total) are important here. Although harder to test, the transfer function of the vehicle and it's resonant frequencies do a great deal to affect how it sounds. It is actually easy to measure but most don't know enough about it to use it to their benefit.
Sealed box subs use the captive air as a spring and don't need a burly suspension. Ported subs are the opposite and need the suspension to control the sub especially when the cone goes crazy below the frequency that the port is tuned to.

That Bose system with the port between the rear headrests was probably a bandpass system. The sub sits in a sealed volume and fires into a ported space. All of the sound comes out through the port. They can have all sorts of issues with resonances, frequency response, and keeping a flat curve. When properly designed and constructed, the ported, bandpass, and transmission line designs can be amazing.

Fiberglass, kevlar, and carbon fiber enclosures can sound better or worse than wooden ones depending on their construction design and quality. What makes a box sound great are rigidity and resonances. Curves are inherently much more rigid than flat areas. Wooden enclosures can be improved dramatically by bracing to the center of each flat area. Composite enclosures are curved and harder to resonate but they have to be thick enough for some real strength. This is at least 1/4" for fiberglass and can be as low as half that in carbon with some internal bracing. I can make carbon enclosures that weigh less than 10 pounds and sound better than the same size one in wood at 80 pounds. Another trick is to coat the inside with a product like Cascade V-Block to lower the resonant frequency of the enclosure even more.

Power depends on efficiency. That 86dB/w sub will need several time more power to sound the same as a 98dB/w sub. That rating is how loud a driver plays when powered by one watt and measured at one meter. Always buy the most efficient speakers that you can afford that will still fit the space allotted. The power that isn't used to make sound (the act of cleanly compressing and rarifying air) is wasted as heat. Heat changes the specs of a sub and heats the air in the enclosure which can alter it's tuning.

Outside of the audio system, the car's acoustic efficiency can be upgraded considerably. Spray on, brush on, and roll on matted products work very well. The only drawbacks are expense, time, and weight. My Outback had all of the interior panels covered in Dynamat. Roof, doors, floors, sides, hatch, tire well, etc.. It ran a 75x4 amp under the passenger seat powering a component set up front and a 10" sub in the left rear corner. It looked entirely stock and would surprise friends with a history of serious systems of their own. The box was about 10 pounds, close to 2 cubic feet, was form fit into the cavities in the side of the car, and wasn't in the way of anything.


Some advice:

Keep things simple. If you can find a 12" sub with serious xmax, great cone control, and good efficiency then you can fit the sound of two or three 12" subs into the space of one. Everything is simpler and cleaner and you are left with real space. Less expensive too.

Shoot holes in your plan. The evolution of a great plan comes through beating up the last great plan. Find the flaws, address them, and so on until it is refined fully. You'll save a lot of time and money this way.

Research. Knowing is half the battle. When I did my basement I brought down a known sealed sub and ran it through slow frequency sweeps. I knew what the sub did in an anechoic environment so comparing what the mic picked up at different places in the room told me how much the room was messing with the sound. The room and system were both changed to match each other and the results are outstanding. Flat within 1dB from 13-40k Hz. F3 in the low teens, max dB tested was 158 with a peak of 164. In a 30' long room with only two subs. It would have been closer to 135 dB without the changes and would have had serious room boom and dead (nodal) zones.

ThatA4T
10-15-2009, 12:11 PM
wow u really know ur shit haha thanks!

onemoremile
10-15-2009, 01:04 PM
I have done a few hundred installs. We even took a couple grand worth of equipment and put it into a Grand Prix with just basic install techniques but left it a bit shoddy like Best Buy might do, things like bolting the speakers in without properly sealing them. We then took an identical car and treated just the car and improved on the way the factory components were mounted. The stock(er) car sounded much better other than the low frequency extension which was because of the sub in the aftermarket car. We did it to prove how much the environment matters. We also sold a lot of sound deadening...

Altech75
10-15-2009, 01:59 PM
Dang, onemoremile I am impressed. I just mean dang.

I've heard a single 8" W7 JL subwoofer in a large box in the back of a friends accord. Blows everything and anything you can buy from Walmart out of the water (if he had a better designed box and a second one it would even blow my brothers two grand system away, impressive is putting it lightly).

JL's W7 series is probably the best subwoofer on the planet. So I'd definitely go with one of those. Contrary to belief it's not the size of the cone that matters when producing low frequencies but the travel of the cone. Yeah a larger cone pushes more air which is a good thing, but it can also lead to more distortion. Sound Distortion = Disgusting in my book, but I'm prolly biased since I'm a musician.

I'd go with two 8W7's or a 10 and an 8. It depends on what your limitations are and how much you bass you want (and how much money you want to spend). Properly designed boxes are also extremely important but not as important as the treatment you give your car.

I'd take out all of the speakers in the doors and add sound dampening behind them and add some sound dampening to other keys areas as well. Our cars already have some sound deadening material in them but they're tar based and not exactly the best. Does help explain why our cars are so heavy though.

SecondSkin Audio makes some quality stuff, it's expensive but if you've ever heard the horror stories behind the lesser stuff, you'll find it worth it. Link: SecondSkin (http://www.secondskinaudio.com/index.php)

Let us know what you decide. I'm also wondering if onemoremile will give us some pointers in preparing our cars for bigger and better sound. A sound system is rather high on my mod list.