purplesyrup

Thanks, its been a fun, yet challenging build, can't wait to share it with everyone.

None. If your enclosure is flexxing that bad, you built it incorrectly. And I'm trying to decide if you use the term fiberglassing correctly or loosely...what do your three layers consist of? Too often people are pouring resin over and thinking this is somehow strengthening the enclosure. Skittles is pretty much all.over this one. Everyone is really going around the actual question I asked. I'm purposly not telling you why i'm doing the things im doing. Opinions or guidance on box building is not needed here. I just wanted to know the answer to the question. My enclosure is not flexing, there is not even a sub mounted in it or a bottom on it. The reason i'm doing what i'm doing is to make this enclosure as strong as possible. My fiberglass layers consist of woven fiberglass cloth. I cut the cloth into 4 inch strips and resined around the inside enclosure horizontally slightly overlapping each other. then once set up and tacky added 4" strips vertically slightly overlapping, then another layer added horizontally,.again slightly overlapping. There was no "just pour it in there involved. And I layed the glass in the strongest pattern I found through research. I was just trying to figure out what you guys would do to mdf to make it perform better in a high pressure situation, I want this enclosure to perform as the sub is mounted in a concrete box, its pretty much there.

I agree steel bands would not work on a box. I'm not working on a simple project. I was just trying to find some sort of answer to my original question. From random internet research i've found that I will be ok with the 3 thick layers I've applied.

In a way yes

Through research found that people that fiberglass from scratch use 6 layers for a rigid fiberglass only enclosure, do you guys think I should keep going or stop at 3?

Overbuilt is the goal, the outside of the enclosure has 1.75" wide x 1/8" steel bands, 3 of them, which will stop outward flex, i'm using the fiberglass to prevent inward flex.

Doubling up on wood is not an option, I've already completed 3 thick layers of glass on the internal walls, my question is, how many more should I go. I skipped rope because I need the interior walls to be smooth. The baffle is complete, 1.5 inches sandwiched with 1/4 inch of glass. Sub is a dd9512I

How many layers of glass would you use to reinforce 3/4 inch mdf to make it strong enough to eliminate any flex or vibration?

Is she bangin? Maybe she gave you some thump because she wants thumped, Regardless sounds like you got got a deal

With a 31 hz tune its very likely the sub will have a hard time hitting those tones in common music, play some test tones, I bet the output falls off pretty quick after you pass 45hz.

Sounds in relation to the vent mach thread I posted, how many square inches of port do you have, and what subs are you running. if your vent mach is to low, the sound waves can still be leaving the box while the sub has already started playing another sound

Sweet nice work, what's your opinion on how it turned out, I was waiting for a seat at a restuarant and didn't watch the whole vid or I would have known that. I did a TL on a 4" certain Vega component speaker, ran it in the house off 100 Watts and not kidding, shook the house on 40 hz tones, mounted it in a 6 foot long 4" pvc pipe.

Its that a transmission line enclosure?

Sounds like your having some cancellation issues. Does it do it with the door opened and closed? I built an odd configuration on some 10s once and they would do the same thing, certain frequencies would disappear, then when you popped the trunk open everything was fine, then shut it and the sound waves disappeared on certain notes.

Can you post some pics if the install, how many square inches of port do you have.

Some of the worst scores ive seen come from walls with to many subs in sealed boxes. I knew a dude that put 8 12"s in a wall in sealed seperate chamber boxes, he couldn't break 148-149 db. Thats not right.

ports are jacked

It will be purely a learning experience as you go, all walls are very different from eachother, recently I have found gorilla glue does wonders, expensive, but if you need something to hold its the way to go, havn't seen many people use it, heres the cons, amazing bonding power, it swells as it dries, filling in any imperfections, now I will also mention I have never constructed a wall from inside the car, but if I was, thats what I would use. In the past i've used it to fix where liquid nails failed, and it fixed the problem completely. Example, internal braces broke away from the screws, cause the hole baffle to start seperating from the box, gorilla glued it up, and re screwed, problem fixed. All I can say is go one board at a time, be sure everything is lined up perfectly, let cure, then continue to the next, take your time, do it right. any minor air leak or flimsy board can make your SPL suffer. I had a 4db loss from what seemed to be a minor air leak. you can make some temorairy braces to hold things in place, use a nail gun to hold things together and in place with the braces. they can be removed easily, and the very small holes can be filled in. hope any of these suggestiions help. And good luck on the build

seen those before, they would surely be affected by a moving car, for sure with the windows down. Its still pretty badass though

One way is to weld bolts to the floor pointing up, cut little slits for carpet so they can poke through, carfully measure how you spaced them, drill holes in the bottom of the box matching the bolts welded to the floor, take sub out, seal holes and bolt box down from inside the box, then put the sub back in. the box is officailly one with the car. Another note, some insurance companies don't cover anything not "bolted" to the car, this solves that problem. from this point, use allen head screws to mount the sub, or something else that the crackhead going around stealing stereos wouldn't have and bada-bing. Throw an extra curve by using 2 or 3 different heads on the screws, so even the most prepaired thief will be out of luck. Welded bolts will also not allow any sliding .

No prob,

I'm not really sure, anything else I find out I will contribute to this thread. i'm just glad I finally figured out some accurate and useful info on the subject because it is a vital part of how the sub will perform and sound.

Ok something useful, here's a vent mach calculator. http://portsgalore.stefanhinote.com/?do=ventmach Its amazing how difficult it is to search this subject on the net. I had to search and word this topic about 20 different ways to get enough info to fully understand., I tried to piece it all together the best I could to pass on the info in that topic above. This is a pretty importent aspect of box building that I often never see anyone mention or worry about.

Fizzy, I will try to find a diagram, I found one somewhere, also winisd calculates vent mach when designing a vented enclosure.