Does anyone think its viable/possible to get good results from using the rubber spray they put on cars as an undercoat that you can purchase at places like autozone on the inside of a trunk to deaden sound Vs dynomat? I know ppl with dynomat that say it didnt work at all, so i dont want to spend that much money if its not going to give decent results. My main concern is stopping rattling that can be heard from the outside. Even with low volume bass my tail lights have a horrible buzz, as well as the stock exhaust i believe, a sort of ringing. Or does anyone else have a suggestion to stop the taillights from rattling at least?
Thanks

 

Undercoating can be used to some result, but depending on where the buzz is you may get better result from some expanding foam. I found that most of the rattle from my trunk was coming from the 2 springrods and the trunk lid itself. To fix the trunkrods I wrapped them, and to fix the trunk lid, I used a can of minimal expanding foam to fill the gap between the layers of sheet metal. Now I'm rattle free.

The idea behind products like dynamat, and even to a lesser extent the undercoater is to add weight to the panel and reduce it's resonant tone to below where your subs will rattle it. So undercoating, if applied liberally can fix the problem... your car is going to stink for a while though.

 

Higgity is that foam stuff you used is it yellow colored foam. Wouldn't that look wierd in your trunk.

 

I think the product you're thinking of is "Great Stuff" which is an expanding foam. Yeah... similar to that but you want something that will expand less. Great Stuff and regular expanding foam expand to almost 4x their size, you want a "Minimal Expanding Foam" which expands to about twice it's size. The reason you want a minimal is so you don't buckle your body panels. (even with a minimal you've gotta be REALLY careful when using the product)

And about it looking funny, instead of seeing the trunk color through the holes in the rails of my trunk, you see white styrafoam, it doesn't look terrible... but the improvment in the sound is more than justification for having something to the effect of 20 little spots of white in my grey trunk lid. I'll take a pic at some point to show you what it looks like.

 

Lol higgity don't you put your trunk up for car shows or anything

 

I'm more about the SPL and SQ side of the car show business... it doesn't have to look good to sound good, and it really doesn't have to look good to be LOUD. Basically my trunk is a holding bay for subs and amps. You open it up, that's all you see. (well, those and 4 pool cues... I've got my hobbies)

There's no reason for people to be in my trunk. And that's why the popper cable is disconnected and the seats are locked in the upright position till comp time.

 

(though I do plan to spruce it up a bit this summer... an undecided plan so far. It's gotta be just as loud or louder and sound just as good. Looks may come into it... but they're a secondary concern)

 

i used dynomat and it reduced the trunk rattle 80%. i think it worked just fine but is a ***** to put in.

 

heres a pic of my dynomat

 

Traditionally its not recommended that you completely cover the area in which you are trying to deaden, only partial coverage is needed to get the results you want. Archangelite, you could have spread that out a little more and got the same results in more areas that just the one. That and it gets heavy if you put a ton on!!
Rubber undercoating would have to be sprayed on so thick that it would be pointless and just as expensive as dynamat if not more so!! There are quite a few different brands out there too that work just as well and are not as pricey if that is a concern... Cascade V-Blok is one, Brown Bread another, just have to look for them!!
Good luck and I hope this helped someone at least!!

 

Well honestly i wasnt going to put pieces all over the top so it could be affective, and there is dynomat in the interior trunk as well underneth the carpet.yes it does make the trunk a little heavier, but i like the look, the neons inside my trunk reflect off the wall very well.

 

Hey man i didn't mean it to sound like I was putting you down just explaining my post a little better. My main point is that there are many various ways to go about it! Besides if it looks good in the runk with your neon then more power to you!

 

I was thinking of using dynomat on just my braces in my trunk.
anyone with tips on where to put the stuff (besides just all over like above) that would get rid of the rattle? I dont' want to pay 45 per 4 foot sheet and not get it all (going to do door panels a lil as well as the back deck grills)


that is where I seem to get all the rattle. (1500ish watts of funky beats)

 

what would you guys do about rattling of windows? i just got subs for my other car, and the window rattles like crazy. im surprised nothing else is rattling though, well everything except my window and my plate..what do u guys think?

 

I ahven't had my windows rattle yet.

they ahve been taken out once however to get tinted.
have yours been? could maybe the factory seal not be good enough?

just got my eyebrow done today (windshield top 8 inches)

I want a damn hood with vents now. and some sport light covers. damn accolade for not selling those seperate.