I'm trying to get some confirmation from audio gurus since everbody I ask points me to a different direction. Excuse me if this was covered before, please point me to the right direction.
I am looking to flush mount one 12" Alpine Type S sub woofer in a spare tire well. Here's what some folks at local audio shops been telling me.
1. Piece up wood blocks and use fiber glass resin to mold it air tight.
2. Dynomat (or similar material) the whole trunk and use plexi glass instead of wood blocks mention before.

Do these sound legit to anybody?
Any help/adivce would be appreciated.

 

Forget the plexiglass, fiberglass and MDF is the way to go.

The baffle, [surface sub is mounted to] should be 3/4" MDF, [1" MDF would be better] the rest of the cabinet can be fiberglass. 94

 

Is MDF the fiberboard stuff?
So the baffle should be MDF ( assuming the same texture/shape as trunk board), and everything under the baffle should be fiberglass?
Is fiberglass really necessary?
I understand it needs to be air tight in order to produce the best sound quality, but I still can't understand how fiberglass resin could hold for the long run.
If what you suggest is true this would save me tons of time and money. Thank you

 

MDF = medium density fiberboard.

Yes fiberglass is necessary, but it's not just resin, you need fiberglass mat also. 94

 

Build an actual box, using both fiberglass and mdf. Dont just build a free air chamber, it'll sound like $hit...

check out http://www.the12volt.com

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by digdug18 &raquo;</TD></TR><TR><TD CLASS="quote">Build an actual box, using both fiberglass and mdf. Dont just build a free air chamber, it'll sound like $hit...</TD></TR></TABLE>
This is what keep hearing and I would love to take your advice but I have no clue how to make an actual box that will sit flush in the trunk without being too heavy. I currently have the regular wood box enclousure that came with the sub. If I build a box as you mentioned would it be lighter than that? (My current box is around 40~60 lbs with the sub)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by fcm &raquo;</TD></TR><TR><TD CLASS="quote">Yes fiberglass is necessary, but it's not just resin, you need fiberglass mat also. </TD></TR></TABLE>
Thank you sir, anything else fiberglass related material that's necessary?

 

Fiberglass isn't the easiest thing to work with. I don't want to discourage you from trying it to do it yourself but depending on what your expectations are you might want to have a pro do it for you.

its important to have a solid and leak free enclosure with the correct volume for the specific driver.

Talk to the installer about drivers specs and what it needs and what you can expect.

Keep your BS meter on too.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by s13_240sx_92 &raquo;</TD></TR><TR><TD CLASS="quote">its important to have a solid and leak free enclosure with the correct volume for the specific driver</TD></TR></TABLE>
That's what I thought, and I talked to couple of guys that used to be in car audio business to find somebody who would do some fiberglass work (I worked with fiberglass on in the past, came out terrible due to poor prep) for a reasonable price, but it was out my budget at the time.

I'm planning to buy/gather all the parts for the job, do everything I can within my limits. Since I am trying to make it look OEM as possible (planning to buy and cut out thicker carpeting for trunk), all I really need is somebody to make sure the enclousure is air tight and will stay trouble-free for the long run.

How much would be a reasonable price for a car audio shop to do that?
Just want to get some numbers so I don't have to throw anything at them when they tell me "500 out the door".
Thanks

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by s13_240sx_92 &raquo;</TD></TR><TR><TD CLASS="quote">Keep your BS meter on too.</TD></TR></TABLE>

 

For $500 you should get a pretty good spare tire well sub enclosure, it should sit flush, have at least a 1" thick baffle it should be well constructed and definitely airtight, it should not be as heavy as the box you have now, it should be easily removable, it should not in any way interfere with anything in the car, [except of coarse the spare tire]. 94

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by doubleshotz &raquo;</TD></TR><TR><TD CLASS="quote">
all I really need is somebody to make sure the enclousure is air tight and will stay trouble-free for the long run.

</TD></TR></TABLE>

Getting it leak free shouldn't be too hard, you are going to be layering the fiberglass mat / resin several times over. it can be a little bit tricky getting the baffle board to the "tub". if you wanted you could pull the tub/well part of the enclosure (before attaching the MDF) from the car and fill it with water to check for leaks. This is also how you can measure the volume too.

For holding up long term, i suggest using several layers on mat / resin. trying to keep every thing uniform so there are no weak spots.

Get your self a respirator too.. fumes are no good for your melon.

You might save some weight.. I know is critical for our torqueless honda's ( i don't have the 240 anymore) but it might not be worth all the effort.

You might want to look at a good pre-fab box loaded with a subwoofer. If you just want something to add a little bump and not really into audiophile quality a bazooka tube is reasonably light weight, sound quality is ehh okay. You can't go wrong with a JL Audio wedge, but they might be too heavy for what you are looking for.

Good luck..

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by fcm &raquo;</TD></TR><TR><TD CLASS="quote">For $500 you should get a......</TD></TR></TABLE>
I meant I'd rather not spend 500 for labor if possible

s13_240sx_92,
Thanks for your input, I used to have a 8" Bazooka tube (it's not so ehh okay with me ), then moved up to a 10" Audiobahn amplified tube, now I ended up with a 12" Apline Type S with Alpine mono amp. I'd like to keep my set-up since it was a gift and sounds suprisingly good in my car, ALMOST good as my friends 8" JL (forgot the name but the one with the thick rubber surroundings) in his SRT-4.

How much would be a reasonable labor price for somebody to work on fiberglass and make it air tight (I got a ballpark of the material costs)?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by s13_240sx_92 &raquo;</TD></TR><TR><TD CLASS="quote"> critical for our torqueless honda's ( i don't have the 240 anymore) but it might not be worth all the effort.</TD></TR></TABLE>
Care to explain further?

 

so when you rip up a tire...

what exactly do you do?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by k0rupt_ed &raquo;</TD></TR><TR><TD CLASS="quote">so when you rip up a tire... what exactly do you do?</TD></TR></TABLE>
1. Call my boys with the flat-beds (Got friends working for towing service)
2. Call my boys/family in the neighborhood to bring one wheel/tire
3. Call AAA (worst comes to worst)

Since you mentioned, let me take the time to state I am aware of the consequences due to not having a spare.
Let's get back on topic

 

The da that in my sig has the 4 tens can be made by you for less then 500 buxs. I made the enclosure into the car so its not removable. It gives the car a whole different feel. And will rock the planet. The unit is air tight. It was some thing basic that would not bust the budget and look great. I am re-doing it in leather now. And switching up the amp to amps

 

That's clean! Good job man!!

Yeah that's what I'm tryna do, Just with one sub though.
Did you use the method I mentioned to make it air tight? (fiberglass mat, resin etc)
Do you mind sharing your "budget" set-up? Or PM me please.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by wrx-killer-Sti-eater &raquo;</TD></TR><TR><TD CLASS="quote">And will rock the planet.</TD></TR></TABLE>
HAHAHAHAHAHHA

 

that^^^ looks nice. heres my old setup. i just built a small mdf enclosure and sit it down in the well.
around .8 cubic feet. i had room for more air but thats all the speaker needed. just something simple.

 

JSPECSIR,
Did you make a custom trunk board with MDF?
Or just a box (encoulsure) and cover it up with OEM trunk board and carpet?
Looks good

 

i built the box so that the top of it is even with the height of the hatch floor surrounding the tire well. once the box was in the car and mounted, i traced the oem floor liner onto a piece of 1/8" hardboard. i cut a hole in the hardboard big enough to fit my hand through over where the woofer hole was in the box. i put the hardboard cover in on top of the box, reached through the hole and traced the woofer hole from the box out onto the back of the hardboard. then i removed the hardboard and cut the hole out. this way the 2 holes line up exactly over each other. then i wrapped the hardboard with carpet, put it in, installed the woofer, and screwed the woofer down through the hardboard into the box. i also used a sealent between the box top and the hardboard around the woofer opening to prevent airleaks. ive got all the stuff out in my garage taken apart if you need more pics to get a better idea. also you may be able to use 1/4 " hardboard, for my car i needed to be able to roll the hardboard piece up to fit it in as the floor area is larger than the hatch opening. like i said this was just a simple setup, i dont have alot of time to put into my cars anymore.

 

Sure, I'd love to see more detailed pictures.
I'm curious where you mount power terminals (+/-).
Also, what sealant did you use?
I went out today to check out some pricing and what exactly does MDF benifit that hardboard doesn't?
Thanks

 

their are no terminals, the wire goes from the sub through a hole that is siliconed to seal it and out to the amp. i use silicone, black if i can find it. alot of people use liquid nails but the fumes from it are flammable. mdf is really dense, it doesnt vibrate (or resonate, whatever) with the speaker, their is also high desity fiberboard (HDF) and birch is also a good choice but is expensive. and their is polyfill inside the box also. ill take pics when i get a chance, ill be busy tomorrow. im building a box for 4 12"s to go in the back of my dd civic coupe. haha what can i say, im a basshead.

 

Thanks for the info.
Whenever you have the time I would really appreciate if you would send some pics of your old set-up to doubleshotz@hotmail.com.
BTW birchwood is real cheap around here

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JSPECSIR &raquo;</TD></TR><TR><TD CLASS="quote">im building a box for 4 12"s to go in the back of my dd civic coupe. haha what can i say, im a basshead. </TD></TR></TABLE>
Good luck

 

Okay, back to the top with this..

I've read - somewhere - that if you just put a few layers on of fiberglass right on top of the sheet metal, but not directly... to make your tub..

its not going to sound as clean... it would sound a little metallic..

I read that you are supposed to put some sound deadening inbetween the metal tub, and the fiberglass that you are laying..

is that true?

if so, what kind of sound deadening material do you use?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by bpr0422 &raquo;</TD></TR><TR><TD CLASS="quote"> it would sound a little metallic..</TD></TR></TABLE>
Can you explain how a speaker/sub can sound "metallic"?

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by bpr0422 &raquo;</TD></TR><TR><TD CLASS="quote">what kind of sound deadening material do you use? </TD></TR></TABLE>
Dynomat or any other similar products.
They sell trunk kits but it aint cheap.

Like mentioned above, building a flush box would save you a whole lot.