So! Recently I had my 13.5JL sub system put in by BLKFIN, And was super impressed (gallery). But i found one huggeee problem... More rattles than a rattlesnake.... The rattles would usually hit on a mid/higher note and simply just took the fun straight out of the song. I even drove around for a few days with my hand on the volume dial waiting to turn it down when a long note would come. So natraully i tore everything apart 3 times and got rid of the rattles.. Heres how.

First off, i realized when driving that although the box was tightly squeezed into my trunk, it was still able to get a little air on bump and even rattle the bottom of my trunk including the plastic sides.

Bottom of the Trunk:
I originally thought I would simply go buy some dynamat. But quickly realized it was not an ideal solution unless i was prepared to remove all the panels and spend some serious time rolling and hoping this would be the solution.

Solution
So natraully i went to Joann's Fabric.. What!?! fabric??? Sort of. At this fabric store, as in many others, most likely even Walmart, You are able to buy high density 1" thick foam, at around $14 bucks /yard. Although it is not a great solution for blocking actual sound, it does some good stuff for killing vibrations if room allows for it and you can hide its ugly green face.

I took out the box, amp, rack, and sub. Then i laid in the foam without any adhesives (Used a 1yd, 7in piece). I then laid everything back in... talk about a TIGHT FIT... Instantly I lost my trunk rattles stemming from that area and it feels much more secure back there... huge improvement. However, if your system is putting out some serious 1000+ wattage, you're probably better off with dynamat. However for my 600watt system, it was perfect and now even proctects my box, and trunk area.

The Hatch

This is where I experienced the most rattles and the most problems!.
Firstly, I asked BLKFIN to tape the latch bar because he told me that they tended to rattle. Even so, i still could tell the hatch was rattling, so i added velcro to each side where i could see some once laid. That was my first problem solved.

But here is the biggest and most imporant rattle solution for your coupe. On your hatchback is a light at the top for your back window. It seems innocent enough... But it is the largest source of rattles in your entire car and the easiest rattle in the world to fix.

Solution
On both sides of the panel surrounding this hatchback light, apply pressure and pull the panel towards you, without much effort you realize the panel is actually pretty loose!!!!... So the solution??? Go buy about 18" of velcro (just need the soft side). Apply a long strip between the panel and the window on the long run, and then a smaller size strip on the left and right sides of the panel. Anddd done. That's it. Biggest improvement ever. This thing even rattles when you just drive without some needed help. And the velcro is not noticeable since it goes ontop of a thick black line already there.

The Plate

So once again i was going to just go grab some good ol dynamat but thought... why am i spending 25 bucks on this crap... So what did i doo? i cut down a little bit of that 1" high density foam and made a small rectangle out of it. I then simply used a weeee bit of super glue on the back of it, and stuck it on my plate.. gave just the perfect amount of lift! No more rattles here or anywhere else back there!


This just took my system up several levels, hope it can do the same for yours! post back if you have any questions! know a bit more about some other solution options that were not mentioned.

EDIT: I played a good 40 songs in the car today, and still heard no rattles, although i did realize on some specific frequencies that there was some distortion in the hollow area by the locking mechanism on the hatch. I'll look into it, but will most likely fill the hollow area up with the same high density foam. Also, as mentioned on another thread, I did experience some cloth flap sounds, which is from the hollow areas of the rear panels.... but its very quiet and 100% impossible to hear unless you are standing behind the car, ear pratically on the butt.

Also, on the bottom of your car, where you would add diffusers, there are two metal surfaces that touch each other, which i assume are heat shields. I found that with some VERY LOW and hard beats, these things can rattle. Just a heads up! (Dynamat >A small portion< would be PERFECT to fix this which i will anyways)

Ill give another update soon!

 

Nice write up!! WIll prob be stickied or needs to be.

 

Very nice! Now that you are feeling better, you can fix mine ! I cant wait to hear it now that the tuning is done and that sub should be breaking in too!!!

 

^^ just edited my OP! Check it for more info! and yeah man im down for helping ya out haha! we'll do it when we get them door panels done!!! Back to College this Sunday though...

 

You are correct those two heatshields on each side of the muffler can rattle at low RPMs. Mine rattled on slight acceleration at low speed or at idle with the A/C on. Looking at it I had about a 1/4 in clearance on the right one and virtually none on the left. I just bent it down to get the desired clearance.
BTW I spent a lot a time on the tailgate bumpers, latch, center brake light and lisence plate but the all time it was that left side heatshield rattling.......maybe mine was just a one off but IMO worth checking before doing anything else

 

Did you have any problems with the air vents rattling on the coupes? There are two rubber "flappers" behind each tire that I assume vent the turbulence when you put the windows down in a coupe. Unfortunately these open and close with each bass note and rattle a lot on long notes.

 

Wow...Can we get some pictures PLEASE