Behind Rear Seat

[BOATER]

Upon removing my rear seat during my audio system install this passed weekend, I was suprised to see no insulation behind the seat back, against the back cab wall. Has anyone put anything like "Dynamat" or pad insulation something in with noticable results? I'm thinking that this could help that annoying 2k rpm resonance from the dual exhaust. Any thoughts? This would be a simple job if it helps.

[jkreese]

Hello there,

How did you remove that rear seat? I know that there are 4 bolts right on the back near the bottom of the seat...are there any other bolts? Thanks.

Ciao.

[tsb]

remove all bolts and lift up, make sure to pull the belts down.

boater, you are correct there is no insulation whtsover
but i dynamat my whole interior and even back there. it does help reduce in noise caused by vibration. i have notice a much quieter cabin.

[BOATER]

Is a sheet of Dynamat sufficient? I'm not really familiar with the stuff. Does it come in large sheets? Does it actually provide sound insulation or just sound damping from rattles, etc? I imagine that a good 1/2" or so carpet insulation would work as well, as long as it is properly sealed with duct tape or spray adhesive to the metal of the back wall. I have used "egg crate" foam insulation to quiet down the engine bay of boats.

jkreese - The rear seat comes out really easily. Four bolts at the bottom and four clips (I think) at the top. Loosen bolts, pick up seat and pull toward you. The toughest part was getting the clips back into their slots along the top, right under the rear sliding window, upon re-installation of the seat. But, I was tired and getting impatient.

[nhparrot]

BOATER,
There are cheaper alternatives to dynamat. Materials knowm as RAMMAT, matersials from Mc-Master Carr etc. There are different types of materials - Mass loading, and Sound barrier and absorber products. See the question "Will adding acoustical damping products to my vehicle make my speakers sound better?" on the speakers page of the Audio & Security FAQ in the "Garage".

[bretsch]

I recently completed installing a Dynamat surrogate material called Beaver Tail. Bought the top of the line their product over the internet at half the price. Highly recommend the stuff.

I applied it to the inside of all the doors, behind the seats including the outside of the two vents as well as portions of the floor under the rear seat bottom. I also applied it to the inside of portions of the door panel and speaker mounting bracket and the inside of the roof. It was not a 100% coverage but in the range of 70% of total area.

Results are significant. I still get some road noise from the lower corner of the cab. Looking for the source. I also get some from the floor in the front. Overall there was a great improvement.

I did buy two cans of the Dynamat spray at $20 some bucks a can and trying to decide where the best place to use it. Open to any suggestions.