ok, I made one of these box's about a year ago, and sold it to a forum member with a sub. It was my first try at making a fiberglass box, and it turned out pretty decent. So this time around, I know what to expect, and it should be nicer than my first attempt. well here are a few pics of the sub that will be going into the sealed box. It is an Image Dynamics 8" subwoofer ( ID8v.3D4 ) Aint' it cute!


Here is some of the progress of the box so far, I just started it today, and it was to cold out side to fiberglass. I used an 8" cement forming tube from the home depot, and I cut a ring of .5" MDF to fit PERFECTLY into it. I then shoved the tube up under the dash, and trimmed away at the top portion so it would be form fitting to the underdash.



Here are some pics of my last box I built. If you notice in the pic, the box sticks out from below the dash, just a little bit, this one im building now wont do that.

I will keep you guys updated with the whole build of this box, because I know some of you want the extra bass, but don't want to sacrifice any leg room, this thread should give you a few ideas.

[This message has been edited by Golden86 (edited 04-23-2005).]

And these will cost us how much? I would like to get in line for one, or two if you make something to fit behind the seats.

Nice. I need more "bump" than the stock sub can give. In am open to the new.

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Real cool. I'm definately interested as well cause I don't think I want subs behind the seats. Or on the floor of the passenger side.

Here are a few updated pics of how its going. Fiber glassed the first layer, and I sealed off the back side aswell. It doesn't look all that great right now, but once all the glassing is done, and when I sand it, it will look great.

Thats it for now, I hope I can get more done after work tommorrow.

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[This message has been edited by Golden86 (edited 04-24-2005).]

I could really use something like that in my car!

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Bottle Fed 4.9 V8 5 Speed
87 4 cyl 5 speed coupe
I drive way too fast to worry about cholesterol.

That looks awsome.
How much $$$ would it take for you to make me one?

quote Originally posted by FieroMaster88: I could really use something like that in my car!

ok, heres a deal, you swap in your 4.9 into my car, and I will build you one of these box's, deal...

quote Originally posted by Golden86: ok, heres a deal, you swap in your 4.9 into my car, and I will build you one of these box's, deal...

Yeah, Ok.... You could just make me one. I think that would be a better deal, at least for me. It looks pretty good too. I have the stock subwoofer setup in my car, but I'm running an aftermarket amp on it. It sounds ok, but I need more.

quote Originally posted by zMacK: That looks awsome. How much $$$ would it take for you to make me one?

It would have to be a lot, because it is a pain in the butt to make one of these, and you also have to modify under the dash just a little, like moving a few wires, and the blue dingy thingy. I really like working with fiberglass, and how you can shape things with it, but it is SO messy, and itchy too. Just shoot me an offer, if I like what I see, I might consider making another one.

I'd take that offer, of course, I make no guarentees that the engine will start once it's in the car.

Would you even sell me one, if I gave you money? Seriously?

quote Originally posted by Racingman24: Would you even sell me one, if I gave you money? Seriously?

you could probably guess what my answer would be...

quote Originally posted by Golden86: you could probably guess what my answer would be...

You, Sir, have a PM.

Can you give a rough estimate of the enclosure's interior volume? Barring that, the length and inside diameter (so I can make my own guesstimation) will suffice.

Thanks

I actually filled up the last enclosure with water to find out that it was .3 cubib feet, this one may be slightly smaller.

OK, thanks

Nice project. Many people underestimate how nice a good 8" sub can fill the Fiero cabin with low freqs. Not much power required also (assuming a good amp). I built a similar box but I like your idea better as long as I can get more or less the same volume without sticking out. Yeah, fiberglass is very messy but building a similar box is very easy for anyone. I built my 2nd one out of MDF to avoid the mess.

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Palm Beach Fieros
http://pbfieros.tripod.com

Looks good, keep up the good work

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1985 2m4
Saskatoon, Sask Canada
Visit the Saskatoon Fiero Club Website at
http://www.freewebs.com/saskatoonfieros/
Come chat with us at our Forum
http://saskfiero.suddenlaunch.com/

whats your price im interested in one

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Chris 85 Fiero SE 2.5L of fury
second one in the garage undergoing surgery
See the progress

http://www.cardomain.com/member_pages/view_page.pl?page_id=347941&page

Looks like you could have a neat little business if you did this in batches! There are a couple 8 in subs out there that will work with .3 cubic feet, heck some will work with as little as .1 although I haven't heard one. That is not a lot of air.

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John DuRette
Custom 85 "The Eagle has landed" - All four wheels now on the ground; 87 Coupe in the driveway. "Kinda makes you nostalgic for a Members Only jacket"

yes, this enclosure is VERY small for any sub. I chose the ID8 for that reason, all that it requires is .2 cubic feet of sealed space. This sub is also optimized for sealed applications vs. vented or ported boxs.

[This message has been edited by Golden86 (edited 04-25-2005).]

You have that much space with the sub installed installed in the box? It doesn't look like you even are going to be close to .3 with the huge excursion area. If it does... I think I want to get one or use you post to do my own.

east way to measure is packing peanuts... fill up enclosure (with sub installed) and then pour them into a square box... in this case make a box the correct size or just mark out on one cubic foot box lines in thirds or fifths.

quote Originally posted by Scott-Wa: You have that much space with the sub installed installed in the box? It doesn't look like you even are going to be close to .3 with the huge excursion area. If it does... I think I want to get one or use you post to do my own. east way to measure is packing peanuts... fill up enclosure (with sub installed) and then pour them into a square box... in this case make a box the correct size or just mark out on one cubic foot box lines in thirds or fifths.

Just to let you know, I measured the old box I built, the black one in the pics above. the box measured .3 cubic feet empty, and the sub took up only .02 cubic feet. So that gave me a working volume of .27 cubic feet. Its not a ton of space, but it is better than nothing.

sounds good - I know rockford is't the greatest but i've got my eye on a punch stage 2 that only needs .25 cubic feed sealed

A lot of people will disagree with me, but the new line of rockford is not that bad, I work as an installer at best buy, and I can say its not that bad for the price I get it at, but you can find better if you are paying retail for it. I have, right now in my winter beater, a rockford P2 in a sealed enclosure with 300rms going to it, and I can't complain.

quote Originally posted by Golden86: because I know some of you want the extra bass, but don't want to sacrifice any leg room, this thread should give you a few ideas.

Oh yes, the oh-so scarce and precious leg room of the Pontiac Fiero passenger side.

well, the second layer went on, aswell as two layers on the inside. All I have to do now it wait for it to cure, put a layer of bondo over it, and sand it till its smooth, then paint.

How do you mount it under the dash?

Have you checked fit to see if it sticks out lately?

quote Originally posted by ryan.hess: How do you mount it under the dash? Have you checked fit to see if it sticks out lately?

The last one I built, I used a metal bracket to mount it to the factory location, the 10mm bolt under the dash. It held just fine, and I think I will do the same this time. I check the fit after every layer, it is getting tight, but it still fits like a glove.

Cool tread....... I have very little legroom on my passengers side, due to two 8" subs. Im interested.
-Roy

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Real Sports cars only have 2 seats....

Matching numbers GT
#17889 of 26,402 made in 1988, 1of 241 yellow GT's

this is my favourite setup so far, great work

quote Originally posted by Golden86: A lot of people will disagree with me, but the new line of rockford is not that bad, I work as an installer at best buy, and I can say its not that bad for the price I get it at, but you can find better if you are paying retail for it. I have, right now in my winter beater, a rockford P2 in a sealed enclosure with 300rms going to it, and I can't complain.

I have an 8" Punch1 with 300 watts. It gives plenty of bass. I might prefer a cleaner sound then what it is giving me now, but at listening volumes (less then bleeding eardrums) it sounds mighty good. Not bad for a $50 sub in a $5.00 enclosure.

That's right, $5.00. If you're not terribly concerned about passenger foot room, your local Checkers, Schucks, or Kragen have small cube enclosures for a five spot. I just upgreaded my wiring in the box and it sounds great. I'd still like to have a set up like this or the box that Fastback86 Scott built for his, but this works great in the meantime.

Nice work Mike! We'll have to compare boxes when i get there, of course mine takes up alot of passenger space, but i guess thats what i get for going with a 10" Alpine Type R and putting it in the footwell. I might end up selling that box anyhow, who knows. Its not terribly un-comfortable but finding a grill thingy to cover it was a pain in the butt. Im thinking ill have to make/get something custom for it so i can sacrifice less leg room. Mine is flush with the foot rest on the right side of the footwell. I should have some pictures soon. I am actually still dissapointed with the low bass produced by my setup. I never really sealed up the hole where my speaker wire goes through, and doing that may help in all ranges. It has one heck of a sweet-spot though .

I think I need some height measurements of your box....... I can't seem to squeeze more than .17cu ft out of that space..... Did you have to remove anything?

And to the sub designers out there - is there any benefit to going to a ported design? Or stuffing it with insulation?

quote Originally posted by fieromadman: We'll have to compare boxes when i get there, of course mine takes up alot of passenger space, .

Oh man, I tell ya, my immature dirty mind went into overdrive when I read that line.

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Great idea man, I never thought of using those forming tubes before

two more things... The Resonant Engineering RE-8 is another great 8 inch sub that can be in less than .25 cf of box

...and a ported enclosure will give more output, but typically takes up a LOT more space (I made a ported box for the RE8 mentioned above and it came to .7 cf gross!). Filling the enclosure with stuffing (polyfill) will help prevent any standing waves, and can help give a "better" sound.

Well... according to

http://www.linearteam.dk/default.aspx?pageid=newdriver

My $20 ratshack subwoofer works optimally with a 0.19cu ft sealed box

quote Originally posted by Golden86: A lot of people will disagree with me, but the new line of rockford is not that bad,

Not wanting to veer too far off topic, but what's up with Rockfish? Back in the day, they were awesome. Everyone raved about them. What happened?

I'm very interested in getting something like this for my Formula, and I'd most likley go with an RF speaker and amp.

quote ryan.hess said: I think I need some height measurements of your box....... I can't seem to squeeze more than .17cu ft out of that space..... Did you have to remove anything? And to the sub designers out there - is there any benefit to going to a ported design? Or stuffing it with insulation?

A ported enclosure will increase input sensitivity (more sound output per Watt), at the expense of transient response (musical accuracy). It might improve frequency reponse, too. But as mentioned above, a ported enclosure will be much larger than a sealed enclosure for any given speaker. You also have to calculate the diameter and length of the port to tune the box to the desired frequency range.

Stuffing reduces the speed of the sound pressure waves inside the box. This increases the "virtual size" of the box (which improves sound quality). With the right amount/type of stuffing, you could make a stuffed box perform as well as a larger empty box (up to 40% larger, in some cases). When you stuff a sealed box, you generally fill it almost full, leaving only enough room for the speaker.

Some people use expensive materials designed specifically as stuffing for speaker enclosures. If you have the cash to spend, try it out. Otherwise, pillow stuffing will work just fine.

You can use a small amount of stuffing in a ported box to absorb some of the standing waves. But you don't want to obstruct the air path from the speaker cone to the port. Lining the inside of a ported box with eggcrate foam is probably a better idea than stuffing.

[This message has been edited by Blacktree (edited 04-26-2005).]

quote Originally posted by Blacktree: This increases the "virtual size" of the box (which improves sound quality). With the right amount/type of stuffing, you could make a stuffed box perform as well as a larger empty box (up to 40% larger, in some cases). ....... Some people use expensive materials designed specifically as stuffing for speaker enclosures. If you have the cash to spend, try it out. Otherwise, pillow stuffing will work just fine.

That's probably a better idea than fiberglass insulation... So even though that calculator said .2cu ft would work the best for my speaker, would it benefit to stuff it? Or even make it bigger than .2 ft^3 and stuffing it? How does box volume relate to anything else?