Need help on Friday or Saturday making fiberglass enclosure-$$$ for experienced help

[pianoprodigy]

I built this sub enclosure for my daily driver. The second sub (IDMAX12V3D4)will be here on Thursday. They will be getting about 750W RMS each from a RF10001BD amp. I need to seal the bottom of the enclosure to the top. As you can see, it's all just open right now. The fiberglass doesn't have to be pretty, just functional. I'd be willing to pay for your experienced help as I've never worked with fiberglass before. I'd like to work on it either Friday or Saturday during the day in St. Pete.

http://www.alantripp.com/slk1sub1.jpg
http://www.alantripp.com/slk1sub2.jpg
http://www.alantripp.com/slk1sub3.jpg
http://www.alantripp.com/slk1sub4.jpg
http://www.alantripp.com/slk1sub5.jpg
http://www.alantripp.com/slk1sub6.jpg
http://www.alantripp.com/slk1sub7.jpg
http://www.alantripp.com/slk1sub8.jpg

[Notladstyle]

theres not much too it for something so simple, just lay three layers of aluminum wrap and lay the resin hot(as in lots of hardener so it dries in ~20 mins) onto some old tshirts cut into 10"x10" blocks.

Once you get the bottom layer, pull it out(it will take the aluminum with it) and recoat several times.

Coat the bottom of the wood with fiberglass and let it dry.

Once you have a satisfactory layered bottom, lay the top on and use more shirt to make the seam to the wood top.

I would be willing to perform the construction for you but since I get the feeling you want to do it yourself It wouldnt be worth it to pay someone.

[pianoprodigy]

I don't so much want to do it myself as just kinda help out and watch to learn.

[Notladstyle]

I don't so much want to do it myself as just kinda help out and watch to learn.

$120 parts(55)/labor45/travel(20)(its about 90 miles from me) and ill complete the project in front of you.If you have the resin, some wood to brace, aluminum foil, and mat subtract the parts *edit* miscalculated resin cost

[TBSpyder]

You've got tools and a garage?

[pianoprodigy]

You've got tools and a garage?

What tools do we need? Yes, I have a garage.

How long are we talking here? Start to finish.

[TBSpyder]

What tools do we need? Yes, I have a garage.

How long are we talking here? Start to finish.

Tools-wise, you're going to need some wood working tools...atleast a jigsaw, 1.25" screws and screw gun. Atleast a manual staple gun (and staples), preferably an air nailer and air stapler, and some sharp scissors.

Supplies-wise, you'll need ofcourse fiberglass resin, mekp hardner, woven fiberglass matting, atleast a square yard of fleece or someother absorbent fabric, several disposable mixing cups, several pairs of rubber gloves, several disposable paint brushes, some wood atleast 3/4" thick, aluminum foil, and a six pack.

Also, on a side note, I'd wrap the carpet around and under the current false floor you have shown in the pics...it'd look alot cleaner.


Start to finsih, I'd say it would take about 3-4 hours.

[93ex]

Honestly, I'd see what kind of space you could get boxing it off first and having a 'glass bottom only. Waay less 'glass work and less hassle.

[Notladstyle]

Honestly, I'd see what kind of space you could get boxing it off first and having a 'glass bottom only. Waay less 'glass work and less hassle.

glassing the bottom as opposed to just coating the whole trunk isnt much more work. Since its all gonna be hidden under the face it doesnt have to be extremely even layerd. Just work it hot and brace it good.

[93ex]

glassing the bottom as opposed to just coating the whole trunk isnt much more work. Since its all gonna be hidden under the face it doesnt have to be extremely even layerd. Just work it hot and brace it good.

Time and materials say otherwise. @ a 2% mekp mixture you get about 20 minutes of working time and 10 of drying time. at that rate,with my method, I've done it to my own car in about 2 hours. Less Surface area to glass, less hassle with bracing and thickness, less glass, less brushes, less resin, less hardener, and I'm willing to wager youve got the scrap mdf around.

[Notladstyle]

Time and materials say otherwise. @ a 2% mekp mixture you get about 20 minutes of working time and 10 of drying time. at that rate,with my method, I've done it to my own car in about 2 hours. Less Surface area to glass, less hassle with bracing and thickness, less glass, less brushes, less resin, less hardener, and I'm willing to wager youve got the scrap mdf around.

Makes sense, if it was a single 10 or even possibly a single 12 that would be cool but hes trying to fit two subs in there. Its already looking like its gonna be tight, the extra time now will make ears happy later.

[93ex]

Makes sense, if it was a single 10 or even possibly a single 12 that would be cool but hes trying to fit two subs in there. Its already looking like its gonna be tight, the extra time now will make ears happy later.

I did it with 2 12w0's in my civic. Sounded fine, side from the rediculous overpowering of the 12w0's.

[Notladstyle]

W0s require .5 cuft each to perform properly - IDMax subs are IB subs that require a minimum of 1.1 cuft each 1.7 nominal.

[TJElite]

Since the IDMAX will work in an infinite baffle, the real goal is just to block the rear wave, not necessarily 'seal' the box. Also, the metal trunk pan, with its curves and shapes, is really pretty rigid. Dynamat, which you have, will stop any nasty noises.

What am I getting at? Foam. The stuff in the can from home depot. Skip the glass. I'd either build a wooden frame, to screw the false floor / baffle to, and foam it in place, or just foam the baffle/floor in place. Sure, it may not be absolutely ideal, but it will work just fine. The foam is cheap, easy to work with, and tough.

Just make sure you cover anything you don't want to get the foam on, because it tends to get everywhere, an doesn't come off real well.

Toby

[Notladstyle]

Lease vehicle - would that foam be removable? if it is then its prolly agood idea.

[pianoprodigy]

Lease vehicle - would that foam be removable? if it is then its prolly agood idea.

The enclosure (as badly sealed as it is) is too large right now so while the foam would probably seal (but would make a mess), it doesn't solve the problem of too much airspace. By some rough measurements, it's at least 4 cu ft. I want to end up much closer to 3 cu ft if not even a touch smaller.

I installed the other sub and the new amp last night. The panel needs to be braced more if I keep this setup. I'm still racking my brain trying to come up with a way to just make an MDF box that will be sturdy with enough airspace.

[TJElite]

The enclosure (as badly sealed as it is) is too large right now so while the foam would probably seal (but would make a mess), it doesn't solve the problem of too much airspace. By some rough measurements, it's at least 4 cu ft. I want to end up much closer to 3 cu ft if not even a touch smaller.

I installed the other sub and the new amp last night. The panel needs to be braced more if I keep this setup. I'm still racking my brain trying to come up with a way to just make an MDF box that will be sturdy with enough airspace.

First off, why do you say its too big? The IDMAX can run in anything from about 1.3 each to infinite baffle. The bigger the box, the lower the bass, the more efficient the system. I would definitely not be concerned by 1 extra cube in this situation. Exact box size, for sealed enclosures, probably doesn't even make the top 5 or 10 important factors.

Second, if you just have to get rid of a cube or so, use foam. You can either buy a couple blocks of it at the craft store (so its easy to measure) or just put some big blobs in with a can.

And lastly...I didn't see that the car was a lease, but its still not a big deal. Won't be any bigger problem than the dynamat you already have in there. In fact, I'd rather remove foam from a metal panel than dynamat.

Toby

[pianoprodigy]

First off, why do you say its too big? The IDMAX can run in anything from about 1.3 each to infinite baffle. The bigger the box, the lower the bass, the more efficient the system. I would definitely not be concerned by 1 extra cube in this situation. Exact box size, for sealed enclosures, probably doesn't even make the top 5 or 10 important factors.

Second, if you just have to get rid of a cube or so, use foam. You can either buy a couple blocks of it at the craft store (so its easy to measure) or just put some big blobs in with a can.

And lastly...I didn't see that the car was a lease, but its still not a big deal. Won't be any bigger problem than the dynamat you already have in there. In fact, I'd rather remove foam from a metal panel than dynamat.

Toby

Toby, it's not really a lease. I lease the car from my dad. All the dynamat will be covered up with the exception of the portions on the deck lid which were done very carefully so that they would look clean.

While a larger box may make the system more efficient and play lower, you also will lose response. I listen to mostly rock music, so I'm concerned with response.

I did think of the foam idea, although, I would think you would want a harder material since you don't want the waves to slow down (as in polyfill) as that makes the box perform as if it is larger and not smaller. I was thinking of either building another small mdf box to go under the magnets of the subs or getting a couple of phone books and duct taping them up, lol.

I'm going to see if I can talk to someone at Image Dynamics now to get their input.

[Notladstyle]

Toby, it's not really a lease. I lease the car from my dad. All the dynamat will be covered up with the exception of the portions on the deck lid which were done very carefully so that they would look clean.

While a larger box may make the system more efficient and play lower, you also will lose response. I listen to mostly rock music, so I'm concerned with response.

I did think of the foam idea, although, I would think you would want a harder material since you don't want the waves to slow down (as in polyfill) as that makes the box perform as if it is larger and not smaller. I was thinking of either building another small mdf box to go under the magnets of the subs or getting a couple of phone books and duct taping them up, lol.

I'm going to see if I can talk to someone at Image Dynamics now to get their input.

Waves only slow down when its stuffed. And even then most dont subscribe to that theory.

Subwoofers dont lose response until you exceed the VAS.

[TJElite]

Toby, it's not really a lease. I lease the car from my dad. All the dynamat will be covered up with the exception of the portions on the deck lid which were done very carefully so that they would look clean.

While a larger box may make the system more efficient and play lower, you also will lose response. I listen to mostly rock music, so I'm concerned with response.



Actually, the larger the box, the lower the QTS, and therefore the MORE control the motor has over the cone. The short definition of QTS is the tendency of the speaker to resonate (think ripples on a pond). Smaller numbers mean less tendency. QTS is made up of mechanical Q (QMS) and electrical Q (QES). QES comes from the motor structure, and QMS comes from the cone, surround, spider, etc, as well as the air in the box. In a large box, or infinite baffle, QMS comes almost exclusively from the cone structure. In a smaller box, the airspace acts more like a spring, and starts to contribute to the QMS, and therefore, the QTS. Some of the power generated in the motor is now used to fight the air spring.

Imagine pushing a rock (low QTS) vs pushing an underfilled water balloon (high QTS). With the rock, you push it, it moves. You stop pushing it, it stops moving. The water balloon, however, starts by absorbing some of the energy of the push, then finally gets moving. When you stop pushing, it sloshes back and forth a little first.

Until you get to about 3 times VAS, the woofer is still under some influence of the box, after that, QMS is considered to be exclusively from the cone structure.

I have 3 12's in an IB setup in my lexus, and it is extremely accurate. You might find that you don't like the sound of a bigger box as much as a smaller box, but it won't be because of lack of control or response. Actually, what most people like about the sound of smaller boxes is the lack of control, that creates more 'fullness' in the upper sub regions. This 'fullness' is acutally just harmonic distortion, which acts to boost some of these frequencies.

In any event, 4 cu. ft. won't be a problem for a pair of IDMAX's...their VAS is almost 6 cu ft each. But if it is, foam is fine for taking the volume down. Stuffing a box classically means polyfill, which actually has a thermodynamic effect, due to its low density and long strands. Its like oil in a shock...some of the spring of the air is turned into heat from interaction with the polyfil. Closed cell foam will do this as well, but to a much, much, smaller extent.

Seal up what you got, and try it. If you don't like it, chuck stuff in there to take up space. You could even silicone chunks of 2x4 inside, if you'd like. Better yet, take up the space with bracing...you can't have too much of that.

Toby

[TBSpyder]

Lease vehicle - would that foam be removable? if it is then its prolly agood idea.


I'd say foam would be about as removeable as that dynamat. Ever tried it? It's fun. :monkdnce:

[P057]

I'd say foam would be about as removeable as that dynamat. Ever tried it? It's fun. :monkdnce:

dont they have a chemical agent to break it down easier?

err.. maybe that wouldnt be such a good idea ever


"dad, i think i got a bunch of semen-looking goop all over the trunk"

[TJElite]

dont they have a chemical agent to break it down easier?

err.. maybe that wouldnt be such a good idea ever


"dad, i think i got a bunch of semen-looking goop all over the trunk"

Methylene Chloride actually does a fairly good job of breaking down the foam to a removable snot. Nasty, nasty chemical, though.

Best bet is to rip it off, as much as possible, sand off what's left, and put carpet, or something, back over it.

Toby