Okay I was looking through the
Parts Express catalog and came accross a pink noise generator and thought of a project....
Lexus cars have been known to have some of the quietest interiors, but after looking at their design concepts, their approach is very simple. First, they foam fill the chassis with a high-density polyurethane foam that both insulates the cabin as well as adds rigidity to the chassis to improve handling. Infiniti does this as well...
Next they have a unit installed on each vehicle that consists of a small piezo speaker and a noise generator. The concept is simple: Take an audible sample of road noise at various speeds, then using an RTA, configure the frequency at each given speed. Create an algorithm that changes the frequency at various speeds and feeds it to the generator, then reverse the phase of the speaker!
Doing this cancels out the frequencies of most road noise to give you that quiet luxury sound without a lot of the added weight of dampening. Note that some dampening will still be required...it just doesnt have to be as dense. What do you think?
I wonder how hard it would be to make something like that?
