hemogoblin

Can anyone give any tips on getting my rear deck to stop rattling? I have removed the stock sub, and the entire bracket that it clips into, and put 2 layers, and in some parts 4 layers of raammat on the deck. Still extreme rattling. Any ideas? Car is an SC300.

engin_ear

iTrader: (1)

If you have the hole open to allow the bass to enter the cabin, you've removed some of the stiffening that the stock woofer formerly provided. You now need to lower the resonant frequency of the deck again. You might want to add stiffeners to the deck. One way to do this is to get some L-brackets from Homo Deep-o. The ones that are a few feet long, with holes uniformly in them at about a 1-inch spacing. You can cut them to length and bolt them to the underside of the deck, using holes at regular intervals. Adding some extra weight to the deck will also help, apparently the Raammat isn't heavy enough.
You may also need to get your rear deck cover to stop vibrating. Adding a foam layer between the deck and the cover should help, and also help with the metal deck vibration as well, AND provide an extra layer of sound deadening. Thin carpet padding should work OK. I need to do this to mine, but haven't gotten around to it yet, so I can't comment on how well it actually works. (I'm waiting until I add another EQ so I only have to take everything apart once.)

hemogoblin

Have you tried this or know anyone who has? Im going to set an entire weekend to get rid of this damn rattling, and taking my box out is a very tedious task.

engin_ear

iTrader: (1)

I have done this, but not in an SC. (I have a GS.) It is always unpredictable, however, as far as the results and effectiveness you will get using any given method, due to the particular car characteristics and resonances, how much SPL your system generates, placement of your sub(s), etc. Generally a trial and error method, and not very scientific. Difficult to analyze. If you take a look through all of the posted commentary on this website regarding sound deadening and rattle elimination, you'll find that some people that have tried the very same things have had similar results, while others have had it work completely for one guy, and not at all for the other. You'll find that some people are OK with one layer of Dynamat or Raammat, whole others need 3 or 4 layers, etc, etc.
You'll need to try to effectively tie the deck to other parts of the structure, so that it isn't flopping in mid-air. Using the brackets to stiffen the deck by tying the center areas to the outer edges (where the deck connects to other large areas of metal) should help. Adding dense foam between the deck and whatever is above it will help to dampen vibrations. You might also want to consider adding thicker steel plate (maybe 1/8" thick) to the deck to increase its mass, especially if your woofer(s) fire directly up into it.
Good luck.