On the maiden voyage of Oscar the ability to talk to the passenger was hindered by the amount of noise echoing through the cab. I invested in a lot of Dynamat to get the noise down to regular conversation level. I took the time to measure the noise level at an idle every step of the way. I will continue to add to this post as I finish out the interior with Dynamat and paneling. Below is the original decibel level without any sound mat of any kind.
Just for reference a vacuum cleaner is about 80db. So imagine driving in your car with a vacuum cleaner on without the benefit of getting anything clean or driving your dog nuts. I started with Dynomat Xtreme on the ceiling and the doors and door panels. Then placed 1/2″ Dynaliner on the ceiling in the valleys of the roof. It brought the levels down 10db to 69db and I still have the back wall, floor and engine-well to go. Not to mention I am creating panels with felt for the back wall, headliner and door panels to cover the mess of logos all over the sound deadener.
I finished up the back wall with 1/2″ Dynaliner and felt panels. As well as filling in a few spots on the top of the engine well.
I have liner material to put n the underside of the cab as well but the hydraulic lift for the cab has crapped out on me so I need to figure that out. Most of the noise is coming from the engine so the Hoodliner will make the most difference. I know that because after finishing 2/3’s of the back of the cab the noise level was still at 69 decibels.