Sound Proofing
Here are some numbers before and after adding sound dampaning material. We did not add any material to the front foot well. Almost four layers were added to all the flat areas in the rear and one to two on all curved areas. The materials used were butal rubber and vinyl foam.
Before at rear view mirror 91.5, foot wells 94.8, door 93.2 and the rear 98.75.
After at rear view mirror 88.7, foot wells 91.35, door 88.6, rear 89.0.
The doors on the before reading were already treated when the speakers were installed. I think the decrease was from the rear noise not echoing through the car. I can tell a big difference and so can everyone I talk to on the bluetooth.
The added weight is noticable when driving the car. Personnally I think it drives better. To me the rear seemed light at high speeds, it has now settled done a little.
These numbers are from a Nismo. I do not know if the other models have any added noise reduction from factory.
Troy
|