By car home demolition and other media
of low or mid-size car noise of car door panels, fenders, engine
compartment and other image point of view, I combined a few car-mounted
navigation experience when removed interior panels.
I found that noise is a very rare thing, good sound effects like the original car's sheet metal design, original car plastic, sheet metal thickness is good, vibration noise is small. These looks are not the late change.
But I also found that low-noise universal car filling a large area of ??sound-absorbing cotton, thickness are about 2cm, full of all aspects of the position. For example, the center console inside, interior plastic plate inside, interior door panels, under the seats, floors, fenders, etc., are very large area fills, and thicker than the thickness sx4 lot.
In addition to my experience watching play HIFI, HIFI equipment is necessary to reach a certain level. Further equipment placed to achieve very high accuracy of the calculated position, the most important point is that you must put a variety of listening room sound-absorbing materials, large cabinets, traps and other sound-absorbing walls, small rugs, curtains and sound-absorbing material. The sole purpose of doing so is not free to make multiple reflections of sound diffraction.
Then again, the car easily transmitted noise or noise occurs where, if you can not do noise or eliminate vibration, noise or another has ended, based on the array, and then filled with a lot of sound-absorbing cotton, the effect will multiply it.
If you do not do a lot of sound-absorbing insulation filling material directly in the plastic interior floors, hollow, firewalls and so on it. How will it effect.