Wil's95SE

iTrader: (3)

Okay guys, redid the trunk lid on thursday with 2 layers of Dynamat extreme. I already had 2 layers up. This morning I took out the rear deck lid to do around the speaker holes and the false port hole i had built in to allow bass to come into the cabin more and take pressure out of the trunk. Had the volume up to about 8 or 9 and still got a lot of I will call trunk flex right where the Maxima lettering is on the trunk. I'm about to go spend another $64 on some Dynamat Extreme to try and rid the trunk from flexing as much. Anyone else have any suggestions? I don't mind buying the Dynamat but if someone knows what else I could use then I would be happy?

Metal Maxima

iTrader: (30)

http://forums.maxima.org/showthread.php?t=414337

Wil's95SE

iTrader: (3)

Yeah looked through that when you first put it up for post. I have several of those combinations in the car now, carpet matting from a carpet store, liquid dampening (fatmat). The problem with the matting is that it's way too thick and my trunk lid carpeting is very difficult to remount with the carpet matting. I've looked into trying to cut it in half but that's hard to do. Does anyone know of any carpet matting that's thin but has good acoustical properties?

filtor1

iTrader: (7)

Don't worry to much about "acoustical properties" when dealing with your subs. I put 4 layers on the inside skin and 4 layers on the framework of the trunk lid and it still jumps around like a sprayed roach. Covering or refitting the stock carpet cover to the trunk lid will be very difficult. You would have to trim off some of the deadener where the carpet is attatched to the lid. I personally just left the carpet off the back of the trunk lid. The thing that sucks about 4th gens and bass is the seats don't fold down. Your subs are just pressurizing the trunk, which in turn is flopping the trunk lid around. I have noticed not only a huge difference in output when the seats are down but also a lot less trunk lid flexing. The only suggestion I could give you is add a couple more layers and forget about the carpet.

Wil's95SE

iTrader: (3)

Yeah, been considering that. I just asked Dan (Metal Maxima) what type of matting he's going to use for his project.

Metal Maxima

iTrader: (30)

I would simply buy a gallon of Sludge...if you use the whole gallon, I think you will be MOST satisfied.

CHECK IT OUT HERE

A single coat will yeild 40sqft. of covering. This stuff rocks!

For my trunk deadening I am going to be using:
1 layer Damplifier
1 layer Sludge...really thick layer
1 layer carpet padding

This should pretty much handle everything for my trunk. I am spending waaayyy more effort on the cabin since I only have a single 10" sub that is facing towards the cabin...for this reason I will be spending signifcantly greater periods of time on the rear deck and rear seat decks.

BBOYSTEVIE

If trunk lid rattles aren't solved by initial dampening, theres a couple avenues you can go that can help.

Obviously more dampening.

An acoustaical absorber like ensolite (seem my post in dampening sticky)

Make it so the latch that holds the trunk lid down is just a tad tad tad further down...aka lid closes snugger. It's a shame. For some cars (like my old Tercel even) that metal trunk lid latch is adjustable, as they supply not just a hole but more of the oval that has a range where you can mount it. The Maxima does not, but I think with a little bit of easy rigging, you could move that "latch" down a cm or two and that really helps keep that trunk closed snug.


Expanding foam (aka great stuff from Home Depot) . First off, if you use this, be warned to block off everything around that you don't want to get messed up. They sell this in some sort of non expanding, expanding, and super expanding styles. Where this can help is if the trunk lid (I haven't gotten inside the Maxima's yet really, but i'm sure it's got some of this) has metal with little holes covering the next layer of metal, it can help to fill the whole thing with expanding foam. This treatment can also be useful for rear decks. Spray it in, it expands snug against all nooks and crannies, fills in the entire gap in the trunk lid (or rear deck in between the two metal sheets) and stops rattling. Wait for it to cure, and cut and sand off exxess.

Hope one of these options works for you.

maxgtr2000

iTrader: (29)

This will sound crazy, but if you do all that and it still flexes (which it probably will depending on your volume) fiberglass the trunk carpet on the trunk lid. It will allow the bass to reflect off of that more solid surface instead of the trunk lid. Sounds crazy but it will work. The fiberglassed capret shouldn' rattle if you do it right and have that deadner already applied behind it.

Metal Maxima

iTrader: (30)

^^^^ No it won't. Fiberglass will flex equally as hard as the metal would, particularly if you only did 2 or 3 layers. Adding the sludge and what BBOyStevie said will fix the problem just fine.

Wil's95SE

iTrader: (3)

Just bought some sound proofing vinyl from a local place here. The lady says it's the best product they sell. They seemed to have a vast variety of sound dampening/deadening material available and can customize anyway you need it. The place is called Extreme Soundproofing and the website is www.yahoosoundproofing.com. I will try and apply some this afternoon and let you guys know the results. If it works like she says, I may become a distributer for it.

Unibomber

all i used was the expandable foam on the lid and for around the lock and lights on the trunk lid i used insulation for home theatres with a high r value.

'96MaxGLE

iTrader: (1)

Have u put any dampening on the inner trunk skin?

Metal Maxima

iTrader: (30)

You could only really use padding for that area - That will only serve for barrier loading; Will's problem will require mass loading at the point of flex.

Wil's95SE

iTrader: (3)

And that's exactly what the vinyl is good for. It's mass loading vinyl. I have about 10-15 sq ft of it so i will have plenty left over. Hey Dan maybe i could send you some of it to try out if you like. Don't worry bro, it's on me.