Can't shake the rattles...soundproofing experts?

[Paniller]

I've only used the paint on eDead v3 so far. I used two gallons. I did a light coat on all 4 doors, then there's a thick coat on the rear seat, trunk, and both sides of the rear deck. I'm still getting vibration from the subs, dual 8" free-airs. (They hit suprisingly hard, btw).

I can't tell if it's the trunk or rear deck that's vibrating, or the top/sides of the trunk. The only part that has light/no v3 coverage is the back pillars by the rear deck, and some sections on the sides of the trunk wall. The vibration seems to be 80-100hz by my guess, maybe a hair lower. I know it's not the Onstar or what appears to be its backup battery. Those are both out.

So, what areas on our car rattle the most? I had two 10's previously, and it rattled a bit as well, but not quite as much. When those go back in with the second amp, we're gonna have some serious vibration issues.

I'm ordering ~25-30 feet of the stick on stuff, to seal the rear deck....any important areas to hit with the remainder of it?

[R.Penguin]

Huh?

[Paniller]

Huh?
Trunk/Rear still buzzes on bass hits, what parts need more soundproofing?

[G8H8]

Around the plastic grommets on the rear deck. Before you snap the rear deck back on use a little silicone on the grommets and then snap them back in. The silicone will hold them snug and stop them from rattling.

[Paniller]

Around the plastic grommets on the rear deck. Before you snap the rear deck back on use a little silicone on the grommets and then snap them back in. The silicone will hold them snug and stop them from rattling.
I'll keep that in mind. Right now it's vibrating naked, with no panels, grommets, etc. I won't put them back in until I cure the rest of the rattle first.

[dandragonrage]

Put pressure on stuff with your finger/hand and see where it's coming from. If you put pressure in the right spot with the music playing, the rattle will go away (from that spot). If you just put your finger lightly, you might feel it vibrate.

[R.Penguin]

OoooooH! You use that soundmaker thingy! :wacko:

[gearhead455]

So your the guy next to me at a red light with the vibrating trunk lid? lol

Turn that thing down before you go deaf. :devil:

[Paniller]

Put pressure on stuff with your finger/hand and see where it's coming from. If you put pressure in the right spot with the music playing, the rattle will go away (from that spot). If you just put your finger lightly, you might feel it vibrate.
There's really no place where I can touch that'll stop vibrations. It's almost a whole body vibration, nothing really ID-able.

[BobtheMonkee]

OoooooH! You use that soundmaker thingy!

you are totally lost :spank:

[Paniller]

Looks like even with a thick coat of that eDead paint-on on the top and bottom of the rear deck, it's still buzzing. It's just too thin of a metal. I'm adding the thicker peel & stick tonight.

[J Wikoff]

There's really no place where I can touch that'll stop vibrations. It's almost a whole body vibration, nothing really ID-able.

That's the same impression I got when I tried. I had a small section of peel and stick that I applied to the onstar battery and the little box by the left woofer, and a couple clips that *might vibrate, and I tightened down the woofer collar things, but none of it seemed to help much if any.

[Paniller]

That's the same impression I got when I tried. I had a small section of peel and stick that I applied to the onstar battery and the little box by the left woofer, and a couple clips that *might vibrate, and I tightened down the woofer collar things, but none of it seemed to help much if any.
The Onstar battery is hopeless. I took it off and threw out the mount. It has screw holes, so I remounted it underneath in the trunk by drilling pilot holes and selfmounting screws. Foam inbetween, of course.

The little box next to the driverside woofer is the antenna/relay for the keyfob/locks I found out. If you disconnect it, you're remote won't work. I just stuffed some thing foam underneath it, plus a layer of dried rtv to make a rubber bumper.

That being said, the rear deck is just very thin, and it took many, many layers of peel & stick to dampen them. It still vibrates with certain frequencies though. Either that or the sub is distorting from too much oomph. probably a combo of the two. The deck seems to be the source of all my woes.

[J Wikoff]

Hmm, that's the FOB antenna? I wonder if I move it so it isn't wrapped around the front of the left woofer, it'll have better range...?

[Paniller]

Hmm, that's the FOB antenna? I wonder if I move it so it isn't wrapped around the front of the left woofer, it'll have better range...?
Oh wow...never thought about that. I'm not sure if it's the antenna, but if I disconnect it, the fob doesn't work. It could just be the relay for the switches, the antenna may be elsewhere.

I just closed everything back up, and the 3 bolts holding the rear deck cover on are crossthreaded on...so I'm not gonna open it back up and check. I'd have to get new bolts and rethread everything, which I'm not in the mood for. But if someone else could, that'd be great, lol.

[J Wikoff]

My range is pretty good, but I might do it anyway. That box does have a 1 foot-or-so plastic antenna thing with what looks like a metal strand in it. And an FCC id on the box.

[Paniller]

My range is pretty good, but I might do it anyway. That box does have a 1 foot-or-so plastic antenna thing with what looks like a metal strand in it. And an FCC id on the box.
Interesting, mine had no antenna. It looks like they realized the range was an issue and installed an antenna in 09?

[J Wikoff]

Mine was taped to the wiring to that box, and it wrapped around the front side of the woofer housing. Didn't look like a good place for reception.

[fourthmeal]

Stabilize floppy metal with MDF or plywood...or more metal if you're good w/ the stuff (I am not!)

Once the metal is stabilized, then you can put CLD on the flat sections of metal that will resonate, and a vinyl barrier over that (with a closed-cell foam decoupler) to finish it off.

[Paniller]

Stabilize floppy metal with MDF or plywood...or more metal if you're good w/ the stuff (I am not!)

Once the metal is stabilized, then you can put CLD on the flat sections of metal that will resonate, and a vinyl barrier over that (with a closed-cell foam decoupler) to finish it off.
I have a 6" x something MDF board that's getting screwed in from the bottom. I was about to do it last night, but I left the garage door open and instigated a mosquito attack. I had to retreat. Hopefully that'll work well enough, it'll be a pain mounting because the rear deck isn't flat at all.

Afterwards, I'll carpet it all from below to hide the mdf.

[Paniller]

The MDF got rid of a little buzz, but the next trouble spot is the hook where the pass-through door hooks onto. Any ideas for this? How do I make that pass-through hold closed tighter?

[fourthmeal]

Use closed-cell foam to close the gap. Specifically either make a gasket to press against OR take a thick piece of foam and use an exacto-knife to cut a slit in the center. Make the slit just big enough to slip this over the hook.

[NDM]

I have used memory foam in the past to kill rattles. It is not the cheapest solution but a layer of it will conform to the shapes under the cover and it is very acoustically dead to noises penetrating it...

Might want ttry a layer of it...You could get some from the walmart bedding section.

[dandragonrage]

Foam will help when you have one weak surface that vibrates against a stable surface, like door panels. It is not for controlling your entire rear deck flexing, if that's a problem. You need to add rigidity for that, not damping. I was going to suggest running some steel box tubing along with the rear deck for that specific problem, but it seems I was beaten to it.

But, like I said, for interior panels, foam can be the solution.

[NDM]

Foam will help when you have one weak surface that vibrates against a stable surface, like door panels. It is not for controlling your entire rear deck flexing, if that's a problem. You need to add rigidity for that, not damping. I was going to suggest running some steel box tubing along with the rear deck for that specific problem, but it seems I was beaten to it.

But, like I said, for interior panels, foam can be the solution.

Maybe I was not clear....

The memory foam can in fact stop rattles too. It may not be able to stop the deck from flexing but it can in fact stop rattles. I used some 1.5 inch memory foam padding sandwiched between my rear deck and the cover of my old mercedes. I had tried all sorts of stuff but could not kill the buzzing. I killed most of the flex from dual 13w7's ported but the annoying buzzing was left. By sandwiching the foam it killed the buzzing for good.

This works because the memory foam was much more dense than regular foam. when I put the rear deck cover back on, it compressed the foam more and essentially provided the pressure against the cover to kill the specific rattle that I had going on.

An added benefit of this was that there was less radiant noise coming from the trunk too because this foam is so dense.....Try it...go target, walmart, etc and temporarily open a box ot the stuff. squeeze it to feel how dense it is and then put your ear up to it.....you will find that it is like putting ear plugs in your ears....


I am not saying that the foam is a cure all,,,,but we are all on here trying to solve this poor guy's problem and it sounded very similar to the one I had in the Benz.....


Oh and BTW....the flexing in the Benz was so bad that I had to make a support in the middle of the deck going up to the rear-most portion of the roof...It killed the flex in the roof and the rear deck.
This was on top of all the dynamat, clay, and regular closed cell foam.

The support was good for 1.5 DB on the meter:woohoo:

[fourthmeal]

Any good foam will work but make sure it is a closed-cell type to avoid mildew and mold contamination.

[dandragonrage]

All foam can hold water and harbor mold, open or closed cell. Don't put it where water is expected to be, and IMO a mold resistant chemical is not a bad idea.

[fourthmeal]

>>..? really? Unless you grab a needle and poke holes in the foam, closed-cell foam has closed cells, which means it will stay mold-free inside. Anything can mold on the outside, but it never does because it is in the path of a decent flow of air. I bet a paycheck that if you install eggcrate foam or "jute" in place of closed-cell foam in a car in a place that gets wet, the results will suck bad. I've seen it done, I've cleaned up the mess.

[NDM]

>>..? really? Unless you grab a needle and poke holes in the foam, closed-cell foam has closed cells, which means it will stay mold-free inside. Anything can mold on the outside, but it never does because it is in the path of a decent flow of air. I bet a paycheck that if you install eggcrate foam or "jute" in place of closed-cell foam in a car in a place that gets wet, the results will suck bad. I've seen it done, I've cleaned up the mess.


I am with you on this....closed cell foam all the way....

the deflex pads are better but not worth the price....

even closed cell foam can be treated....but you take away some of its effectiveness with the treatments..

And from experience, eggcrate foam turns to muck in a bad way after just a little while...

[Paniller]

Wait a minute...why am I reinforcing the rear deck? Can't I just cut it out? lol. If I stuck with IB subwoofers, I'd need it for the "enclosure," but If I use sealed boxes for all the subs, do I need anything?

It looks like I'm adding weight when I could be subtracting weight. Has anyone been crazy enough to cut out the center of the rear deck? I can't see how it's necessarily needed, unless it's for structural stability and/or safety.

[dandragonrage]

Taking out the stock "subwoofers" should provide ventilation enough for a trunk box. Or if you want, take around a 4" holesaw (or whatever tool you want to use) and add a few holes from it.

[MoonRunX]

It was a line level converter, nothing but a splice into the rear speaker wiresusually, so when you fade, your subs fade w/ rear speakersif I were you, I would use butt-connectors to reattach the wires, pigtails are no good.

[JoshHefnerX]

Do not completely cut out the rear deck. It provides structure for the seat back, provides a hardpoint for the center seatbelt and also for the child anchors. What you could do us cut out a bunch of it and leave a few strips there for the hard points - then weld some steel in to reinforce those (small square tubing). Should give you a better/flatter surface to work w/ and you'd be able to make a rear deck on your own out of mdf.

Josh

[Paniller]

It was a line level converter, nothing but a splice into the rear speaker wiresusually, so when you fade, your subs fade w/ rear speakersif I were you, I would use butt-connectors to reattach the wires, pigtails are no good.
huh? What's this have to do with the rear deck and rattles?