ok so there have been quite a few threads about the problem of having a subwoofer in the trunk and the back deck including the 3rd brake light vibrating and making annoying noise.


Has anyone actually figured out a fix for this. One person used sound deadening material to no avail. Anyone have an actual fix for this problem?

 

Don't turn up the bass too high. Works for me, lol..

 

that definately does not work for me!

 

lol. I can imagine how much bump you're making, you have 2 15"s solobarics? I only have one JL 12w3.

 

common need some help here guys and gal.

 

I've got 2 '15 Audiobahns. I was having the same problem u was but mine isnt so bad now. I originally put dynamat on my trunk lid and behind my tail lights. That seemed to work for a while but I still had some rattle. So I just recently added 2 more layers of dynamat to my trunk lid. I still get some rattle from my spolier and I'm getting a little from the bottem of my back bumper. I was told that there wasent too much I could do about the spolier rattle and the only thing that I can do to fix the back bumper is to re-enforce my bumper. (Which I have no clue how to do) I'm not sure how to stop the 3rd brake light from rattling but I'll be working on that this weekend and if I come up with something I'll let u know.

 

when you say trunk lid.....you actually mean the lid? or the rear deck where the rear speakers and 3rd brake light are mounted?

 

for the 3rd brake light :
most of the noise is coming from where two plastics meet, i.e. the bulb assembly and the actual housing. I applyed hot glue to the seams, so the plastic stops rubbing. It's a little ghetto, but it worked out well.
for good measure, i taped off some areas and the sprayed a thin layer of dynamat spray (1/8" thick)

rear deck:
I used 2 layers of dynamat xtreme (top and bottom), I also replaced the oem foam/carpet under the deck with dynamat's "tacmat", the pink stuff, it also worked well.

A lot of the noise comes from the rear portion of the head liner. (sit in the middle of the rear seats and look up) there's 3 clips supporting it. gently pull it down (about 1.5") and then put a few pieces of foam in between the headliner and the metal roof.

after doing those 3 steps, I noticed a pretty big improvement.

 

good thread.....

I've been thinking about this a lot over the last few days.....my rear deck has been annoying the hell out of me lately, and I think my lid has gotten worse too. I had sound deadening put in throughout much of the trunk, and that seemed the eliminate those obnoxious out-side the car vibrations, but inside remains to be another story. My audio guy told me that sound deadening on both sides of the deck would likely make significant improvements, and I guess putting some kinda insulation up in the liner might be a good call too....if anyone else has any tricks, please share!!

 

I removed my back brake light from the rattling and have since cut ot alot of metal in the back deck so the bass comes through more. The flimsy top wobbles like crazy but the rebuild project on the back deck hasnt progressed as quickly as I thought. School is intense right now. You can do a search for "bass improvement project" to see what exactly I did. gl

 

the easiest way of finding exactly what is making the noise is to remove every thing back there i.e. the rear deck, seats, side pillars and 3rd brake lamp, then play a bass tone (~80hz), if the noise disappears then for sure it was one of the parts that you removed. I if the noise is gone, then reassemble one part at a time, repeating the bass tone in between.

Another part you might want to address is the trunk torsion bars (under the rear deck). they tend to rub against each other under high vibration. Buy about 10ft. of rubber hose (the thinner the better, as long as it wraps around the bar), i bought window washer fluid hose from autozone. I slit it in half and wrapped it around the bars, to secure it i used black zip ties. cheap fix, works perfect.

Yet another area that can be addressed is the vent that's on the rear left, (on my 97 es, but every car has it, just look for it), It's usually located on either the left or right side in the little storage area on the side, I think Lexus stored the factory jack there. I guess it to release the pressure when you slam the trunk lid. Well, Lexus used some flimsy rubber flaps, that tends to make a "flapping" noise from the outside.
there are 3 ways reduce the noise, (1) stuff a thick piece of foam to block the vent (wedge it between the metal frame and vent), (2) seal it with dynamat, or (3) carefully pull it off so you could reinstall it if needed (that's what i did).

 

You have to be very careful about cutting metal under the rear deck, the energy (bass) must enter cabin w/o too much restriction, or else it will cause more rattles! The pressure from the bass will push the panel above the hole, which will tend to rattle easier.
BTW, most Lexus already have a stock sub integrated into the 3rd brake lamp, so just remove the sub.

 

You have contradicted yourself newcomer. I cut out a buch of metal in the back deck so there would be less restriction of the bass coming through. Big Hole=less restriction, less rattling, and more bass coming from the trunk into the cabin. Think about it. No stock sub in my rear deck though.

Nice Four.1 btw. I love mine.

 

Big hole on the metal=no hole in the panel above the hole=restriction...that panel will jump like hell.

I wouldn't doubt that the bass would get louder, but noise would also too. how hard is that to understand?

If you read the discussion title, 3tdelement is a asking about "sub vibration on rear deck," not "how to get more bass from your system." If that was the question I might have recommended cutting the deck, but i would have warned them about potential rattles.

maybe ditch the rear deck speakers (If you have it), but if you cut it already, then i shouldn't waste my time.

 

I have yet to convert the flimsy top to match the changes I have done on the metal section. So yes of course it would rattle if the job was not completed. The bass certainly increased but the noise from the rattling top isnt as bad as one might think. There are cubed chunks of carpet in all the right places that prevent almost all of it. Soon enough I will finish the job and replace the entire flimsy top wish something much stronger with less restriction.