Miracles should not be expected, but still a real improvement in the sound. In addition to relieving the built the original speaker in the car. Strong bass response through the speakers in the doors led me to unpleasant noises especially from the rear doors. Better insulation of the rear doors brought only limited success. By shifting the deep bass frequencies below the driver's seat with the subwoofer, the problem was solved. The device has a very good controllability by the wired remote control. I have a few days used to the correct settings of bass reproduction to find with tone controls from the radio and gain control of the subwoofer.
