Need help with Dodge Charger box for FI Q 12"

[mlgreen 10+ year member]

I have a FI Q 12" and my Dodge Charger is a bass sponge that rattles like hell. I have deadened the entire trunk and it still rattles and sounds like ****. So I'm thinking about firing the sub forward sealed off from the trunk. Do you guys think it will be a good idea to have my sub firing forward, sealed off from the trunk, and have the aero port running up from the box through the rear deck into the cabin where the old factory 8" sub was? Or would this cause cancellation issues? It would be tuned to 32 hz in a 2 ft3 box.

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[Sonic. 10+ year member]

Both sub and port firing into cabin from the sealed off area with rear seat folded down.

 

[mlgreen 10+ year member]

That would be ideal but what about when the seats are folded up? I really don't like having to drive around with my rear seats folded down plus I have passengers in the back seat a lot //content.invisioncic.com/y282845/emoticons/frown.gif.a3531fa0534503350665a1e957861287.gif

 

[E-Rock 10+ year member]

You should probably also deaden other parts of your car as well.

Even with your seats up it should be fine. It's not like the trunk is sealed off. But other people on here know more than me, so I'll let them be of more help.

 

[mlgreen 10+ year member]

Hmm looks like I'm going to try a fourth order firing through the armrest or firing up through the 8" opening where the factory sub was. With a 4th order box nothing has to be sealed off correct, just the port opening firing into the cabin?

 

[dbeez 5,000+ posts]

How did you deaden the trunk what was used and where in the trunk.

 

[mlgreen 10+ year member]

I used Audio Technix sound deadening and I did the entire trunk lid, under and above the rear deck, behind the license plate frame, the side panels, the lip of the trunk where it closes and meets the bumper, and the wheel well. These cars are rattle traps and bass sponges no matter what you do with a rear firing set up. That's why I want to do either forward firing sealed from trunk or 4th order with a blow through going into the cabin from the factory 8" sub opening or the rear arm rest. I heard a 300c last week with the rear seats down that had 1 12" Type R with subs and port firing forward sealed off from the trunk. It was waaaaaaaaay louder and cleaner sounding than mine with almost zero rattle, and he didn't deaden his trunk nearly as much as I did mine.

 

[dbeez 5,000+ posts]

But here's what you didn't do there are voids between outer and inner sheet metal on the rear section as well as trunk lid did you do anything to fill that void expanding foam or anything prior to just slapping deadner over it to cover it up.

 

[mlgreen 10+ year member]

Yeah i didn't want to mess with expanding foam seeing how messy it is and how it can warp the hood. Doubt it would have made a difference on the charger forums there's people who did that and still have rattles. Plus I don't want to do anything that permanent, hell I really didn't want to put any sound deadening but least that theoretically can be removed. I'm pretty much set on a forward firing set up after hearing one.

 

[mlstrass 5,000+ posts]

I've run a few forward firing set ups, currently run one in my Altima. Bass sounds a little tighter/cleaner, but doesn't hit quite as low. Probable since cabin size shrinks and peak goes up.

 

[Jroo 10+ year member]

I just listened to an Infiniti with a 4th ported through the ski hole. Not a rattle anywhere and he didnt do one bit of deadning at all. Some of this has to do with how solid the car is at the start. Some cars, no matter what have more rattle than others. Outside the car you heard a faint bass hit, but when you opened his doors there it was. I can say if your sub is 4th friendly, but if it is port through that 8" opening which should more than enough port area unless you are trying to be stupid loud. You will have to deaden that rear deck where the port is.

 

[mlgreen 10+ year member]

Yeah those 4th order boxes are intriguing. Plus the Fi Q is very 4th order friendly from what I gather. Decisions decisions...

 

[the727kid 10+ year member]

Your rattle is most likely a single issue or two. Take your time and isolate the problem. My buddy had a 12" BTL and not too much rattle but he had deadened the whole trunk and used ensolite.

 

[mlgreen 10+ year member]

With a 4th order, if the box is ported through the rear deck, does the box itself still have to be sealed off from the trunk to help eliminate trunk rattles? I guess what I'm asking is will the bass be completely channeled through the port. That way all I would have to do is seal the port itself off from the trunk into the cabin?

 

[mlstrass 5,000+ posts]

deck lid will still need to be deadened as it will receive pressure and the trunk panels still might vibrate some. I've done a few Charger trunk builds and don't remember the trunks being that bad, but I did do some deadener.

Main issue was the trunk latch safety device popping the trunk open when playing loud bass...