George Ab
Drag Racing Champion
- Location
- Pacific NW
This is a worthwhile mod that reduces road noise at highway speeds. One just needs to use their ears, get up to highway speed and listen for where the road noise is coming from. You can always test first by removing spare tire and covering fender wells and tire area by taping four or five cotton towels laid out over the area and then go for a ride at highways speeds. Totally understand if one is satisfied with the way the car comes stock. I modify my car to make my car better at the edges. Yes, tires contribute to noise, I use quiet tires; Michelin PSS currently and usually use Continental DWS.
I understand resonance. Any material will resonate if enough energy is put into it. For road noise “25% coverage provides 99% performance of reducing panel vibration noise”. In my case I am driving up to 200 Watts into a 10” speaker firing towards the floor so significantly more energy is being placed into the system. I am good with the amount of anti-resonance treatment I used for my application, if I got overzealous and put a pound more than needed so be it. However, IMO far from “laughable” for the application.
Great input on using felt! Acoustics foam is not that good at absorbing sound as thick cotton batting is vastly superior. However, there are other design considerations. Foam gives more than cotton so you can fully cover where thick cotton batting cannot. You will be able to put your panels back on with foam and get complete coverage. You can line your walls with 8” cotton batting, but if you leave the window open noise will get in. I will likely add ½ inch cotton batting to those areas where I can. My subwoofer meets the upper panel as it is so I don’t have the room under the tire, but will likely add and recommend its use where you can fit it in.
I contribute to the community by sharing my experiments and modifications. However, a critique from a proclaimed subject matter expert “I studied building acoustics design” starts out with “I see many of the threads on various forums & it makes me laugh as the waste of materials....”, does give me pause.
I understand resonance. Any material will resonate if enough energy is put into it. For road noise “25% coverage provides 99% performance of reducing panel vibration noise”. In my case I am driving up to 200 Watts into a 10” speaker firing towards the floor so significantly more energy is being placed into the system. I am good with the amount of anti-resonance treatment I used for my application, if I got overzealous and put a pound more than needed so be it. However, IMO far from “laughable” for the application.
Great input on using felt! Acoustics foam is not that good at absorbing sound as thick cotton batting is vastly superior. However, there are other design considerations. Foam gives more than cotton so you can fully cover where thick cotton batting cannot. You will be able to put your panels back on with foam and get complete coverage. You can line your walls with 8” cotton batting, but if you leave the window open noise will get in. I will likely add ½ inch cotton batting to those areas where I can. My subwoofer meets the upper panel as it is so I don’t have the room under the tire, but will likely add and recommend its use where you can fit it in.
I contribute to the community by sharing my experiments and modifications. However, a critique from a proclaimed subject matter expert “I studied building acoustics design” starts out with “I see many of the threads on various forums & it makes me laugh as the waste of materials....”, does give me pause.