Odd sound from rattle?

Bloodhound50

I took th fram of my trunk out to fit my subs in right (db212) and now they are facing the license plant and it sounds GREAT! However, when turned up loud there is an odd sound in the car, almost like a loud tap on glass, when i open the trunk the sound lessens and when i go back to see if it was the subs, its not! also i can have the speakers at the regular volume i use and it will be fine til i turn the subs up. When i turnn them up i hear it, it apeears to be coming from my speakers in teh door which i dont get. when i push on the door stock grills it lessens as well. mabe becuase so much vibrations that the grill is getting knocked onto the tweeter on my speakers? if anyone has any suggestions id love to hear them.

1996blackmax

Have you put any sort of sound deadener in your install?

Bloodhound50

well i have on the front two speakers. I have also put a pklacemat underneath the license plate which obviouslywont work as well as dynamat or whatever else i could use, my girlfriends cuz said it could be the license plate but never got to hear it. i noticed which scares me a bit is that when they are playing for the first couple minits or so its not really there which leads me to belive it could be the equiptment. i was thinking maybe its my amp connections to my subs but when i open the trunk it lessens and when i go backto the subs they sound fine. its only happened since i cut the frame out of my trunk to get them to fit in. they are also relativly new. (about5 days with like 12 hours playing time). it gets louder when i put my ear near the unamped speakers in the front. it does the same thing in the back as well but more so in the front and my door panels have always rattled alot and one more than the other and it would sound like the one that used to rattle more than the others is making a louder sound. the speakers can play at 30 fine with no distortion but when i turn the subs up from the remote gain then i get the sound but there is a lot of rattling. im going to invest in dynamat for my license plate and eventually a trunk kit. it sounds as if someone where knocking on either glass or the body of my car. its like a POP almost but not so much a im gonna blow soon pop. also the bass boost is at 1/4and the gain at 1/2 so its not as if the subs are being too stressed. i hope someone can help me with this becuase it is such an awful noise that i cant listen to the subs up more than 10% really and i like em loud. just one of my stupid newb ideas was maybe the subs are taking too much power so my HU amp cant power the speakers effectivly? my lights dim with the bass... anyways id love a respone because im very upset over this problem, which is a big one for me.

1996blackmax

First of all, turn down the bass boost and readjust your gains. Unless you have a HU with pretty anemic preouts, the gain control should not be that high, specially when coupled with the bass boost. Adding a good amount of sound deadner should help out quite a bit.



Very useful links here, that will be very informative:
http://www.caraudio.com/forum/showthread.php?t=206371



Easy way to find out what the gains need to be at for your application (if you do not have a multi-meter, get one, they are not very expensive):
http://www.subwoofertools.com/forum/setgain.asp


For sound deadening, SecondSkin is the way to go. They have a very good product that is very nicely priced. Plus if you become a forum member, Ant will give you a discount.

http://www.secondskinaudio.com/cgi-bin/index.cgi

Here is the stuff you need:
http://www.secondskinaudio.com/cgi-bin/index.cgi?p=ps&pg=1

This other stuff is very helpful with rattles from trim panels:
http://www.secondskinaudio.com/cgi-bin/index.cgi?p=ps&pg=3

Bloodhound50

what about Dynamat? thats what ive always used. my friend said they are overrated tho from stuff hes read. than again he siaad bose is overrated from what he read as well. but i can get a trunk kit for 80 on sonic electronix..

1996blackmax

Dynamat Extreme is a good product...I have it in my 96 Maxima. The Original Dynamat I will pass on.. also have it in my 96 Maxima. You are getting 12 square feet of Original Dynamat, and only 8 square feet of the Extreme (20 square feet total). When you consider the alternative, it is still pretty expensive for what you are getting at $80 dollars.

For $96 dollars you can get 40 square feet of SecondSkin Damplifier, which is the equivilant of the Dynamat Extreme. This price is without the forum member discount.

You could also spend $85 dollars on 20 square feet of the Damplifer Pro, which is better than the Dynamat Extreme. Same square footage, and only $5 more dollars.

I would go with the regular Damplifier, very good product, at a very good price.

MacLeod

I agree with Max that the Original Dynamat aint all that. The Extreme however I swear by. Ive used a ton of it in my day and have $200 worth in my Accord now. Its very dense stuff and works very well. There is cheaper alternatives out there but I can get good deals on it from my local shop and by the time you factor in shipping and all that youre really not saving that much.

For instance, I got 2 door kits and a wedge pack for $170 out the door. Not too shabby.

1996blackmax

The thing is that the other cheaper alternatives may not be up to par as the Dynamat Extreme... the Damplifier from SecondSkin is (some think better). I've used both, think both are very good products, but from now on I am sticking with the SecondSkin stuff.

The last 40 square feet of Damplifier got to my door for a little under 97 bucks. You would be hard pressed to find that good of a deal with Dynamat. The price on the bulk pack (36 square feet) of Dynamat Extreme goes for $250 bucks, suggested retail (Crutchfields price as well). Sure you could get a deal from the local shops, but it's not going to get close to the SecondSkin price. Guess you could go the Ebay route, but even then you are still going to pay more.

For a little info, here is a little review (not the end all, but some good info still):

http://www.sounddeadenershowdown.com/

Bloodhound50

I think ive discovered the problem. I have come to the conclusion that the sound is from the speakers. there is additional nosie from rattling as well. When the subs are up to the point when stuff starts to shake the sound starts to sort of cut out. i think it shook the grounds loose in my headunit which powers the speakers. only the speakers produce this sound and on songs with alot of "shaking". It started not so bad and now its getting worse. NOTHING IS BLOWN OR DISTORTING.
-Thanks

1996blackmax

You will still get better sound with sound deadening. In my 02 Maxima I deadened the front doors at different times due to time constraints. Even with the stock Bose system, I was able to tell a big difference in sound from the midrange in the door with the deadening compared to the other one. It had more solid bass, and the other midrange driver sounded kind of hollow compared to this one.

Bloodhound50

yea no doubt it will help. i used two dynamat extreme speaker kits on the front doors and i noticed a major difference. and that was only speaker kits. this friday ill get a license plate kit and eventualy with taxes a trunk kit hoepfully. i heard it will increase from 3-9 db also.