grandprix104 Posted March 8, 2004 Report Share Posted March 8, 2004 Ok so after finishing my trunk make-over project I still have the same problem I had to begin with (except it looks alot better). I had origionally thought the vibrating was just some body panels (specifically the decklid). After applying a sound dampening panel to the decklid (carpeted fiberboard backfilled with fiberglass insulation) I still have the same problem, however, the problem is now obvious that the sound pressure in the trunk is literally blowing past the seal between the decklid and the trunk. My solution to all this would be to add a good sized vent from the trunk into the cabin decreasing the SPL and adding a lower bass note to the passenger area. What do you guys think of this idea and do you have any other suggestions? Thanks Quote Link to comment Share on other sites More sharing options...
per0781 Posted March 8, 2004 Report Share Posted March 8, 2004 maybe this web page would help: http://www.installer.com/tech/rattles.html Quote Link to comment Share on other sites More sharing options...
grandprix104 Posted March 8, 2004 Author Report Share Posted March 8, 2004 i actually had that same box firing toward the seat at one time (just to compare) and it didnt sound half as good (but the back seats were like massage chairs. As far as the vent goes it would need to come up through the metal piece that spans the vehicle underneath the rear window and enter the cabin in the little tray behind the center of the rear seat. As far as folding down seats 1. mine dont fold and 2. even if they did it wouldnt do any good because the area is still sealed off by the back of the box and the fashia. One question though - does that piece of sheet metal under the rear windshield that the speakers mount to actually provide any structural support or is it just hanging there? Quote Link to comment Share on other sites More sharing options...
per0781 Posted March 8, 2004 Report Share Posted March 8, 2004 OFF TOPIC- I've got a 12" sealed enclosure, would it be okay to have the speaker facing the seats? Every car I see has them facing backwards. I just ask cause the box itself fits nice and snug facing the rear seat. I don't have the amp yet to experiment myself.. it would be okay but you would lose bass http://www.installer.com/tech/aiming2.html Quote Link to comment Share on other sites More sharing options...
sonyman87 Posted March 8, 2004 Report Share Posted March 8, 2004 Are that a ported or sealed sub box? You should find out information about your subs, and what is recommended (sealed or ported enclosure). You could always get the SE bucket seats for the back, which have the center console thing that comes down so you can get into the trunk- and if you are able to have a port run to the inside of the car. OFF TOPIC- I've got a 12" sealed enclosure, would it be okay to have the speaker facing the seats? Every car I see has them facing backwards. I just ask cause the box itself fits nice and snug facing the rear seat. I don't have the amp yet to experiment myself.. you can but there is to much air so most of the sound goes to the rear bumper.. if you can try placeing the sub just offset or next to your trunk latch facing the back. i bet you will find it more accusticly pleaseing! Quote Link to comment Share on other sites More sharing options...
89oldscutlass Posted March 8, 2004 Report Share Posted March 8, 2004 You said something about putting vents into your trunk. My Cutlass has them from the factory and it doesnt help with the metal vibrating from my subs. Quote Link to comment Share on other sites More sharing options...
grandprix104 Posted March 8, 2004 Author Report Share Posted March 8, 2004 I am getting a LOT of air pressure forcing its way up through the cracks in through the rear deck panel (carpeted piece under rear windshield, in cabin) if i put my hand back behind the speaker mount I can feel air rucshing up from the trunk. My idea was to make it easier for A LOT more are to move up into the pasenger cabin. Quote Link to comment Share on other sites More sharing options...
grandprix104 Posted March 9, 2004 Author Report Share Posted March 9, 2004 I was thinking i could cut a rectangle in the sheetmetal pictured below and build a vent that would come out through the rear deck, right behind the center of the back seat what do ya think?? Quote Link to comment Share on other sites More sharing options...
sonyman87 Posted March 9, 2004 Report Share Posted March 9, 2004 DONT DO IT! your going to butcher your car and for what more AIR! in theory wont happen it will just slow it down b/c of a larger hole.. i will tell you this, if you want more sound cut out the insulation on the back seat its about 1/4inch thick and will help out alot! as far as anything else goes its not worth it Quote Link to comment Share on other sites More sharing options...
grandprix104 Posted March 9, 2004 Author Report Share Posted March 9, 2004 I dont want/need more sound... All I want to relieve a little PRESSURE so the decklid doesnt rattle like crazy because there is no other way for it to escape. Also i would never 'butcher' my car. Everything I do to modify it is ALWAYS designed/built so that it looks professional. My biggest question is does this piece carry any structural support that would be comprimised by modifing it in this way. Thanks Quote Link to comment Share on other sites More sharing options...
AWeb80 Posted March 9, 2004 Report Share Posted March 9, 2004 Ok, from my personal experience......Place the subs toward the rear of the car and put them right up next to the back of the trunk.........mine are sooo loud that way....and they hit harder too.....and I leave the passway down inbetween the seats, that helps with volume and relieves pressure and keeps my spoiler from shaking off. Quote Link to comment Share on other sites More sharing options...
grandprix104 Posted March 9, 2004 Author Report Share Posted March 9, 2004 ok guys for those of you that didnt notice this thread http://www.w-body.com/forum/viewtopic.php?t=13442 now im not repositioning the subs as they are built in! and for the second time I DONT HAVE FOLD DOWN SEATS and even if i did it wouldnt do any good because the box fashia seals off the opening! Anyway does anyone have an answer to the question above on the structural dependance on that piece? Quote Link to comment Share on other sites More sharing options...
913_4se Posted March 9, 2004 Report Share Posted March 9, 2004 dont forget the spair tire well things fall in to it and make alot of noise Quote Link to comment Share on other sites More sharing options...
92Cutlass4Dr Posted March 9, 2004 Report Share Posted March 9, 2004 Have you tried adjusting the closing mechanism on the trunk to make it seal tighter? i haven't looked at it, but i assume it's adjustable. I've heard of people replacing the mechanism to make it more solid. How does the seal look? maybe replacing that could help. Just some things to look at that might save some time and effort. I wouldn't want to cut a big hole in the parcel shelf, i'm sure it has some structural purpose. good luck Quote Link to comment Share on other sites More sharing options...
musthavemuzk Posted March 10, 2004 Report Share Posted March 10, 2004 i hear ya man i hear ya the rear deck is structural support. if you cut it be sure not to cut any of the supports. the rear deck speakers could be removed to release pressure from trunk into cabin. this is my choice since i do not like rear speakers. if you cut the rear deck any be sure to strengthen the remaining sheetmetal. i would not remove any of the seat foam. or any of the rear deck filler material. typically facing subs to the rear will sound louder to the ear. my choice for daily is to fire the sub up while it resides under the rear deck. but play to find out what you like the best. Monty Quote Link to comment Share on other sites More sharing options...
913_4se Posted March 10, 2004 Report Share Posted March 10, 2004 I was thinking i could cut a rectangle in the sheetmetal pictured below and build a vent that would come out through the rear deck, right behind the center of the back seat what do ya think?? hope you have a STB thats going to flex if not i would think Quote Link to comment Share on other sites More sharing options...
913_4se Posted March 10, 2004 Report Share Posted March 10, 2004 i just read that you cant move them sucks Quote Link to comment Share on other sites More sharing options...
musthavemuzk Posted March 10, 2004 Report Share Posted March 10, 2004 i forgot he put a pic up. mayb remove the rear deck and promote air flow by removing the material you see through the metal openings there. as well as replacing the rear deck material with something lighter that will help with air flow. such as speaker grille cloth. or if you think you are up to the task. cut the rear deck carpet as make it look decent as well so you can look into trunk through the opening. Monty Quote Link to comment Share on other sites More sharing options...
913_4se Posted March 10, 2004 Report Share Posted March 10, 2004 house insulation works to get rid of some noise but not sure thats what you want Quote Link to comment Share on other sites More sharing options...
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