My sealed box story, and ... thanks to everyone

JettaGLI
10+ year member

Senior VIP Member
Ok... SO! I am sure many of you remember the thread about my subs sounding like shit, and the questions I had regarding a sealed box.

First off, I want to say thanks to everyone who has replied to all my posts here over the last 2 weeks. It has been a tremendous help and has brought back to me all the important points I used to know about car audio. (It has been years since I was this heavily involved in car audio, somehow I got stuck on superchargers and V8s????)

Anyways, here is my story.

I bought a 2004 Jetta GLI (the Jetta sport model, 1.8 turbo as I am still stuck on forced induction) and I just didn't want to dump in money into the engine on this car. Soooooo... I turned to car audio instead.

I started out with a simple set of 12w3 v2's and a 500/1 off the stock deck with stock mids. After a year, I decided to upgrade. I got the Avic N2 ( I sell Real Estate so I needed this and it was a write off //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif ) as well as JL VR comps up front and co-ax in the rear powered by a JL 300/4.

Well, this soon spiraled into an amp rack. Once the amp rack was done, I realized that I needed a sub box just as nice to match this amp rack. So I had the car stereo store do a custom fiberglass wheel well enclosure. THe entire setup was built to have a false floor throughout the entire trunk.. all flush to look good, which it did.

However, once I got this all done, the W3v2's weren't good enough. I upgraded to W6v2's and another 500/1 (that makes 2 500/1's powering the now upgraded W6v2s).

I took it upon myself to install the new speakers and extra amp myself, after all, I uesed to mess around with this stuff every day years ago. I did the upgrade with no problems. However, there were underlying problems caused by the shop that installed my fiberglass box. What are those problems..... for those of you that read and helped me out on my previous posts you already know, for those that didn't / don't..... AIR LEAKS!

I won't go into how I started looking for air leaks as I am typing enough as it is, but I did, and I found them, a lot of them.

Now.. I am not sure how many of you are aware of the cracks and crevises there are in a fiberglass wheel well enclosure, but there are a lot.

When I started to investigate, It was dark outside and I was using a light. First thing I saw... YES.. light through the cracks. I had the subs out because I knew there was leak and somone reccomended that I use TRUCK BED LINER to seal the inside of the box. So I went and bought 2 cans and sprayed the shit out of all the tight corners inside the box and a light coat on the rest of the inside of the enclosure. I really messed up here in the sense that..... 1) I had taken out polyfill that was in the box, but still had residue from the P-fill. This prevented the truck bed liner from penetrating every crevis, 2) I put 1 sheet of dynamat on the fiberglass only side of the box before I sprayed the truck bed liner. Well.... there was a major leaking seam behind the dynamat I put down. The dynamat prevented the truck bed liner from sealing one whole side of the boxes leaky crevises.

Problem solved??? I wish!!!!!!! I put the subs in, using weather striping AND silicone on top of the weather stripping for a good seal. After all, the inside should be sealed up with the bed liner.... right? WRONG.

STILL.. major leaks. So, I trace them down 1 by 1. Now, you have to understand that these are not easy to find when you have no room between the baffle and the side walls of your car. TO TOP IT OFF, the installer used staples to attach the baffle and he missed the piece below the baffle, leaving exposed staple heads. It is not easy to run a bead of silicone when there are exposed staple heads (sharp) running along the seam.

At this point, after sealing up 1 leak just to find another, I am lead to a leak in the actuall fiberglass wall. The other 3 sides of the box are backed by wheel well steel, but the 4th side is pure glass.

The installer used a cardboard box and foil to mold this pure wall of fiberglass, I could hear the leak, and finally ripped away all the cardboard I could ( some would just not come off). SURE ENOUGH... I pushed on the subs and I saw lose pieces of foil moving. So, at this point I am just plain seal happy ( or nuts). I have boughten a big tub of paint on sealant and I am just gooping this stuff every where. I gooped it on the leak in the fiberglass wall, and still had leaks.

At this point I should mention that the fiberglass wall flexed very easily so I said **** IT. I called a freind who had some FG resin and we went to town with fleece and resin. After all, this should fix the leak and strenghten the box right? NOPE. 2 layers of fleece and lots of resin and still leaks.

So.... at this point I had learned a little about how resin works. I went to the store and bought a fiberglass kit. I layed 4 more layers of glass, with lots of resin. Let's just say this is a pretty **** solid fiberglass wall now. 8 layers of glass with 2 layers of fleece/resin inbetween.

What do you kNOW, still... more leaks. So, I am looking everywhere I can for leaks ( acording to air sounds ). I am going nuts here.. literally! Pushing on subs, listening, pushing on subs, listenting. To make it worse it is a dual chamber box.

You have to remember here. I have gone through 2 cans of truck bed liner on the inside of the box, 2 tubes of silicone and A 3RD CAN OF TRUCK BED LINER on the outside of the box + weather strip putty in every crack I can reach (sealed off with a silicone based sealant), and a combined extra 6 layers of fiberglass/fleece on the fiberglass only side of the box (outside of box, not inside). This is all on top of the half of a can of paint on sealant I have used (either by dripping into craks I can't reach, or gobbing on shit loads where I can reach).

Finally, the leaks got smaller and smaller and smaller. I trace the last leak down about an hour ago. The fibgerglass is still curing, as well as the half can of sealent I have dripped/painted/spread everywhere.

I know this post is long, (not as long as the 2 days it has taken me to find all the leaks) BUT.... I thougt this post might give someone the determinatin to find every last leak, + explain to everyone who has helped me what exactly the probelm was.

FYI, the box was not made to pop out easily,... Another bad installer decision.

To brake it down material wise:

3 cans of truck bed liner, 2 on the inside, 1 on the outside ( mainly focuse on the area that I covered with dynamat on the inside)

1 half can of some super thick paint on sealant. In the end.. this is the stuff that saved my ***.

About 20 feet of putty weather stripping (sealed with the paint on sealant)

2 tubes of silicone. (this was before the paint on sealant came into the picture)

2 layers of resin/fleece

4 layers of resin/glass (this was done more to reinforce the glass only wall of the box as opposed to stopping leakes).

2 days of time spent going nuts!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

On top of this, after I get both 500/1's installed, one of my subs was cutting out. this was happening due to a faulty subsonic filter switch on one of the 500/1's. It had been this way for a while, but the extra vibaration of the w6's just made the amp not useable. I had it replaced with brand new 500/1 through a warranty replacemnet ( a whole nother story in a different thread).

However, in the mean time I went out and bought a 1000/1 for both subs. //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif This drasticly improved the sound (EVEN THOUGHT THE BOX WAS LEAKING FROM EVERY CORNER) because I have a dual chamber box. This was also a topic you great people helped me with. AND.......... I can tell you that- in a dual chamber box, no matter what JL says, 1 amp is better than 2, and yes I volt mathced both 500/1's.

WOW, this is a long thread. I am so high off fiberglass resin and glue!!!//content.invisioncic.com/y282845/emoticons/crazy.gif.c13912c32de98515d3142759a824dae7.gif

ANYWAYS, I just wanted everyone to know that the leaky box problema is solved, 2 days later.

GOes to show you what doing something yourself is worth.

Thanks again all you Car Audio Forum Members! I couldn't have revisited the past without you!

 
GOOD JOB! i didnt help u but **** hearing your story of sealing up your fiberglass box is whackk lol. nice job on taclking those leaks though. you can never have a too airtight seal.

 
Ya, I rember back in the day, I used to spend a day just sealing a box, but that was out of the car, and on purpose. This was unplanned, and I was lost. It sucked!!!!!!!!!!

I am anal, when something isn't done right and I get stuck on making it right, I won't stop untill it is done.

 
I would have taken the box back and made them make a new one for free.
Well, I thought about that, however, I didn't for 2 reasons. 1- I am a realtor and the installer has hired me to sell a house, and represent him in his new purchase. He invests in real estate, so there is futrue oppurtunity as well.

2, and this is even more what made me do it myself. It it wasn't done right the first time, why would it be right the second time? I have way too much equipment to trust someone to mess with it all. If they can't build a box right, how do I konw they will unhook and rehook all my gear up right and with the same care/quality that I would.

Goes back to that saying, if you want it done right, you gotta do it yourself.

THanks for those who read my story!

I am going to start a photo blog so pics will be up soon. I still have to modify my amp rack cover to accomodate the new 1000/1, and... I am going to cut holes in the rear deck to allow the bass to enter the car. I have so much dynamat in the trunk, that if my seats are up, I loose ALOT of DB's.

There will be a lot of pics, good ones, when I am 100% done.

 


This is the back side of the box (looking in from the back door of the car, the rear seats fold up here). A major source of leaks. You can see the clear sealant I gooped on to fix this side of the leaky box. If I was thinking, I would have just used resin here, becuase the amount I gooped on is still drying 24 hours later.



Another back side shot. All of that black stuff is truck bed liner. It was my first attempt to seal the cracks, before I realized how serious the leaks were.



This is a shot of the back side corner. You can see the cracks on the side are VERY hard to get to. I litterally had to just drip sealant off a paint brush on this entire side of the box. The side wall of the trunk is just too close to get in there.



Here is a shot looking in from the back of the trunk, you can see what I mean about tight space. You'll notice the baffle extends out over the actuall box.



Another shot of the back of the box. This is just after I sprayed 2 cans of truck bed liner on the inside of the box. I thought my problem was solved. You can see I haven't sprayed the outside back of the box with truck bed liner yet. I had no Idea just how bad it was at this point.



Another shot of the box before I realized how bad things were. Notice the diff. between this pic, and the first pic?



 
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JettaGLI

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