I was searching the topics around here looking for glassing the interior of a sub box, and didn't find too much. My question is. My sub calls for 1 inch MDF but my installer says he will use 3/4 and glass the inside to "keep the weight down". Do I have anything to worry about as far as flexing and structual integrity? I want to do a sealed enclosure about 1.6cu.ft. Are there any other suggestins for a sealed box? I want to do it right the first time as my funds are a lil limited. Hey thanx guys!!

3/4" will be plenty strong, and glassing that is a good idea to eliminate air leaks. No worries!

Just wondering what sub says it requires 1 inch mdf?

thanks duran. They are PG titanium elite 12's. It was a concern because in my sub lit. it says MUST use 1in or (2) 3\4 because of the "intense internal combustion and weight of the driver." Thought that was a rather funny way to state a speaker! I thought cumbustion happened under the hood, not in the trunk. It's gonna blow!!! LOL

Edited October 14, 200816 yr by RaTtLz

combustion... your confused

"A single layer of 3/4 mdf is not recommended due to the intense internal combustion chamber and weight of the driver." That is a direct quote from the litrature. I would understand "compression" chamber, but not the stated cumbustion. What would be your interpritation bigjon?

indeed...make sure the spark plugs on the subwoofer are still in good condition.

And also you MUST use high flow fuel injectors...Seam foaming the enclosure helps smooth out the response also.

Double baffle and lots of bracing and 3/4 inch mdf will work. My xxx 18 has lived in a double baffled box, 3/4mdf and has seen around of 3kw on burps. No problems with the box

haha internal combustion. Somebody from PG was having a clown day.

As for MDF, 3/4 with glass is fine. I think fiberglass is stronger than wood anyways.

Those are some pretty serious, rare, and expensive subs. Where did you find them? and what box is this that they're going in?

Why not use 1"? Or better yet, 1.5"

If he is just going to resin the inside of the box it will be weaker and not stronger. Make sure that he also uses mat and string as flat surfaces really aren't the best for fiberglass either and it will also need reinforcement.

I'd expect it to be much cheaper to just use 1.5" instead of doing any fiberglass.

x2, but at 1.6 cubes some internal bracing with 3/4" would take you above and beyond strong and you'd avoid having to double up on all sides.

Resin only seals , adds no strength. Glassing a flat piece of mdf is pointless. You would gain so much more structural rigidity by simpling bracing it properly.

haha internal combustion. Somebody from PG was having a clown day.

As for MDF, 3/4 with glass is fine. I think fiberglass is stronger than wood anyways.

Those are some pretty serious, rare, and expensive subs. Where did you find them? and what box is this that they're going in?

It was a rare find on woofersetc.com. I got 2 of them for 625.97 shipped!! I've read horror stories from there but I couldnt pass up the deal. It took 4 days shipping from cali to minn. and everything arrived perfect serial numbers and all.

Have you modeled them up in some software with the box you intend on using? IIRC, those were some kinda pesky subs with regards to their frequency response and what boxes they like. But the one install I'm thinking of had one 18" and an 18" passive radiator and it was a number of years ago.

I have tried WinISD with the nubers I have but there were some incomplete fields so I think that threw the model off some. Here is what I have:

Fs: 25.2 Hz

Re: 1.47 Ohms

Qms: 5.1

Qes: .616

Qts: .55

Vas: 47.7 Liters

Mms: 268 Grams

Cms: 149 uM/Newton

Vas: 10.07 Tesla-M

SPL: 90.2 dB

Sd: 477.2 sq cm

Since I was going for sealed musical PG recommends Vb: 1.6 (includes sp. displacement) with an F3 of 33 Hz. With the #'s I put in Winisd says 2.02. If there is a better modeler let me know. I am constantly learning as this is my first "real" project where I am paying more attention to what all of the T/S parameters are and what they mean. Thanks for any advice!

I hope to nab a PG Ti Elite for my collection at some point.

I use winISD as well. It looks ok. Sealed isn't as much of a hassle as ported.

glad to see there is another PG fan here. here are a few pics from my install of (4) PG Ti12d Elites I used 1 1/8" MDF all around with a double baffle. So the top is 2.25" MDF

Sweet ! Do you have it up and runnin yet? Unfortunately, I am waiting for a douche from ebay to send me my refund (been a month). I was plannin on getting 2 more subs and another 3000d. How do they sound? Do you have any Spl #s? Sorry for the questins just excited is all.

yea its up and running i love the way it sounds i just need to work on my front stage still as far as numbers go i hit a 147.9db@38Hz on the dash sealed up I know there is a little more left because the two sundown amps shut down due to low voltage. Hope to go to another comp soon with my new 300Amp alternator see what i do now

yea its up and running i love the way it sounds i just need to work on my front stage still as far as numbers go i hit a 147.9db@38Hz on the dash sealed up I know there is a little more left because the two sundown amps shut down due to low voltage. Hope to go to another comp soon with my new 300Amp alternator see what i do now

What's the specs on your box?

its 11.15 cu ft tuned @ 28Hz

are you TRYING to get banned?

"A single layer of 3/4 mdf is not recommended due to the intense internal combustion chamber and weight of the driver." That is a direct quote from the litrature. I would understand "compression" chamber, but not the stated cumbustion. What would be your interpritation bigjon?

im in my "mech" school right now....we are learning about the combustion section and various other sections of jet engines..and i can tell u that a sub is in no way related to a combustion chamber....its just marketing

and btw, a box made of .75in mdf thats braced well will be stronger than a box made with 2 layers of .75in mdf thats not braced

are you TRYING to get banned?

haha no chit