12/25/2022 0 Comments Mass loaded vinyl vs dynamat![]() ![]() I wonder if the rear side panels, glass and hatch are big transmitters of noise? I will show some pics when done. I tried this out with cardboard and insulating foam and thought for the first time that road noise was reduced to an acceptable level. I am putting a bulkhead between the front and the back of the car. Good sound, good reduction in other noises but still very intrusive road noise that as you say seems to radiate from everywhere. Went fairly crazy on the doors as I was doing a stereo install. I did a big install with sound proofing pretty much everywhere you mentioned. $300 and 70lbs in material nearly "wasted" so far (I have each piece of material weighted on ounces).Īt this point, I recommend leaving these cars stock, or buying a steel-chassis vehicle for something quieter.or using lower pressure/different tires. The work done here typically quiets other cars down drastically though, even with cutouts for things like the speakers, no covering of the seat cross brace, etc. The cutouts for the speakers maybe allowing noise into. The noise as I have it IS wheel noise - it sounds like other cars do when driving over certain overpasses or bridges. I have the door jambs do deaden, but it sure seems like the entire car body is making noise, and that we would be better off just changing the resonant frequency by using products like dynamat (constrained layer dampening). Polyfill in open (to the sides of the battery box) won't do anything to "block" noise - mass does that. A stethoscope doesn't really help for lower frequencies. Now the question is - WHERE is this sound coming from? It still sounds like it's coming from everywhere. I did some more trimming during installation, such as around the IMA box air intake. I did not touch the doors yet.īelow is what the car looked like. Material was installed up the driver side floor too, but a lot of trimming was done for the pedals. I installed material underneath the metal plate on the passenger side. I have up to 2" of overlap between pieces, except the center console piece is right at 0 overlap when everything is bolted down, and the brace where the front of the seats bolt - this I covered, but there is no overlap. ![]() I covered the center console and the aluminum plate behind the rear seats, from top to bottom. Starting with the front of the vehicle, I covered the floor from front to back, halfway up the firewall. These are far from the frequencies typically classified as "road noise". With C-weighting, this showed as 102-103dB on the rough highway, at 61Hz. Initial readings showed 90-91dB at 60mph on rough highway at 400Hz, 78dB at 60mph on smooth, fresh pavement. ![]() I wouldn't remove the IMA box, but I would add material under and to the sides of it, without covering any ventillation holes. Pieces would be cut to cover every surface in the car, up to the top of the wheel wells, up halfway the firewall, etc. My plan was to adhere the mlv to the ccf with DAP Landau Top and Trim adhesive. ![]() I expected to use 50 square feet of material in the Insight, with a huge drop in road noise. To start, I picked up a cheap calibrated mic (Dayton iMM-6) to use for comparison of the before and after. This would be my first time using MLV in a custom install. I've had good luck with those other products in layers, with thin closed cell foam as the final "barrier", some 10 years ago. I skipped products like Dynamat, Damplifier, RAAMmat, etc since the goal is mainly to block road noise. In an effort to quiet down the noisy Insight, I picked up 100 square feet of 1/4" closed cell foam (ccf) and 100 square feet of 1lb mass loaded vinyl (mlv). ![]()
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