I want to get a couple 12" RF HE2 subs in a sealed box to put in my 1997 a4. I am worried about the back rattling like a MOFO. I was told to use dynamat all around and that should stop most of the rattling. What have you guys done to your cars as far as systems go and what have been the results....how do they hit, how is rattling, and anyhthing else. I thank now (Sens-ayyy)!

that should all but eliminate the rattles and tighten up the bass. Also, it wouldn't hurt to dynamat the bottom of the rear deck as well, as that could have a tendancy to resonate and vibrate.

While you're at it, do the doors and that might also improve the tightness of the system up front.

Good luck, and let us all know how it turns out.

Oh, by the way, When I say Dynamat, I mean, you can use any other brand too... dynamat is sort of a generic term nowadays... sort of like Xerox or Coke or Kleenex. There are other brands that work well too... Brown Bread and Cascade are two that come to mind right away. One thing about Dynamat that I've heard, is that certain types of Dynamat can tend to stink like tar in the hot summer months. Also, if you are concerned about going fast and want to add minimal weight, take a look at all the brands' weight specs too.

If not, the subs will fire directly into the back of the rear seat, muffling the sound quite a bit, and also probably producing more rattling. I figure since the subs have less space to fire into with the seats folded up, the rattling would be worse, so you would still have to Dynamat everything anyway.

if the box "fires" into the cabin and is sealed from the trunk, it won't exert pressure on the trunk, therefore not that much rattle. The bass will be muffled if the seats are up, but if its loud enough it won't matter. My suggestion would be to fire them back and if it rattles then dynamat it.

No doubt that less bass is heard in the cabin if the seats are up. But if one were to make an enclosure such that it completely sealed off the cabin from the trunk, I don't think there would be significantly more bass in the cabin (with the seats up), whether the subs were on the front of the enclosure, facing forward, or on the rear of the enclosure facing back. However, the difference in rattling is significantly less if fired forward.

I've seen too many people struggle and struggle to get enough dynamat behind panels, etc, only to have a tough time closing trunks, doors, etc and still have rattling.

No thanks.

I do suggest leaving about 2-3" of air space behind the seats before the subs

That subs often get overdriven to distortion. However those freqs that can be heard during distortion are usually not heard if the subs are fired backwards, with an entire enclosure between you and the subs cones.

Oh, and the best is when a car is driving away from you and you can't hear the bass, but you can hear the trunk rattle. That's just marvelous