4 Fi Audio IB3 18's walled off 15Hz tune in a VAN BUILD LOG

im so tired of caulk, resin, and foam bathes

 

6 cans of foam in there so far, god i hate foam.

 

so this **** is hillarious. now yall really got somethin to make fun of me for. so one of my neighbors, who is a framer, was hangin out in the back of the van with me for a while today discussing how to glue the baffles together and how to glue them to the frame.

After a long session, I said "OK. let's break this down. Either I'm going to glue all the baffles together first, then glue the frame in, and there will be an ah-hah moment where I say damn it I should have put the frame in first then the baffles. Or, I'll do the frame and then the baffles and realize I should have dont the baffles first. So I am asking you. Frame first of baffles".

He said he aint takin the blame figure it out your damn self.

So I did the frame. BTW, IT IS FRIGGEN SOLID! I can move all 5 baffle boards by hand easy but I can NOT make the frame budge even at dead center.

So I was layin in bed, imagining putting the subs in. Want to take a guess?

I'll give ya'll a hint: tomorrow I am taking the front seats out and getting a jack in there.

 

blessing in disguise, now I can attatch each baffle 1 by one to the frame and that frame is SOLID! Glad I used PL PRO cuz I ony used 1 screw per joint just to hold till the caulk cured. It's not even fully cured and its hard as a rock, yesterday when I was putting the frame in it swiveled and shifted real easy..so its all caulk. Cutting off the excess, some of it's still soft on the outside liquid in the middle.

 

im so glad I used foam and not 2x4s, cuz it is hard as a rock, the metal/foam/wood have become 1... a tripple density. I used 11 and 1/2 tubes of PL PRO. The 2x6 frame was already so hard it was crazy, but now..this wall is grenade proof.

If I cut my port down to 10" long... the MDF wall itself is 4" thick, the 2x6 frame runs along it making it 10"... then I'd be tuned to 18.5Hz hahaha. So evben if I cut my port all the way down, bringing it from 85 cubic feet to 95, I still can't get above 18.5Hz hahaha.

 

http://www.youtube.com/watch?v=XQeRCgCJrY4

 

http://www.youtube.com/watch?v=ijzL3U17GN4

 

with all the controversy with using "IB" drivers I thought I'd take a pic of the 1st one in here. There isn't THAT much difference between a "normal" subwoofer, an SPL woofer (burp monster), a SQ subwoofer(home theater sub), and an "IB" driver (Infinite Baffle). The only difference, is an "IB" driver does not have a cone. It does not have a coil. It does not have a surround. It does not have a dust cap. The only soft parts it has is partial tinsel leads and the spyder. The only difference in the motor, hard parts, is the pole piece is pushed to one side in the gap. To acheive this, the 2 slugs have to be separated, usually by a novice on looker who doesn't realize the hard parts are still worth something if it is reconeable so he sets it down a little too hard.

Otherwise, IB subs are exactly the same as any other non IB driver.













2 different kinds of screws: star heads and square heads

 

you guys with sonotubes, how do you cut the thick stuff? I've got 20" so 1/4" walls..utility knife not as easy on this as the 8" and 12" tube

 

the rear chamber is 95 cubic feet after displacement. A 20" port 30" long tunes it to 14.1Hz

The front chamber (if the windows were up and the rear hatch was open) is about 75 cubic feet after driver/passenger displacement. A 20" port 30" long tunes it to 15.97Hz

Here is the impedance plot and excursion plot of the 2

 

you should see it in person! Scares the CRAP outta me every time I look back

sure makes those little 18's look tiny, eh?

 

I forgot to say, I made the 2 cutouts to recess the subs too small on purpose. I cut them a touch small then put the subs in and tried to force them, then spun them so they rubbed where it was extra tight. Then I took a grinding wire wheel and scraped up those areas. I had to use a hammer and chunk of 2x6 to tap/pound each sub in and I didn't even need screws to hold the subs in! That was the idea, I wanted the 2 outter boards to also help hold the weight of the subs...kind of a test for future REAudio XXX 18's. Those things are 80lbs with most of the weight 13" back like Josh, Ricci, said. I drove to Walmart the other day and forgot the sub was still in the wall and I hadn't put any screws in yet! All the stop and goes and turns and it didnt pop out and smoke me in the head! Then when I pulled the basket out and put it in the next hole to tap those screws, each hole the sub gets stuck in there. The basket gets hooked on the edge of the front baffle board and I have to pry it out. Anti-theft in addition to using different screw heads

This pic was right after I dropped screws in, but the screws werent in there when I went across town.

 

sphincter!

 

the tube was a tight fit to begin with, ther's a whole tube of PL PRO on it...if it ripps with the 4.5" thick glue job, then bolts arent gonna help any