there is a delay of one or two seconds when the carplay is used, so that the car can play video files on the big screen, but there is a premise that the car is in a stopped state, because the state stipulates that it is forbidden to play videos when the car is driving, so you can't play and watch videos while driving, including the entertainment system in the back row. This is a personal attempt, so the original intention of the state regulations is to drive safely to protect yourself and pedestrians. If you have to watch the video, you can only brush off the relevant safety modules, but there are potential safety hazards that need to be informed in advance, but this operation is highly recommended, because it is very likely that other safety modules will be wrong or even invalid in order to watch the video, which will affect driving safety. There are two reasons for the preliminary judgment. The phases of the tenor and bass are opposite, and the bass is delayed as a result. Second, the frequency connection between bass and tenor is not done well, resulting in frequency fault, which will also cause the sound to be out of sync. In addition, if the volume of bass doesn't match the treble, it will also cause the difference of phase and frequency, and the result will be out of sync. Solution: Turn on the music, open a front door, and keep your eyes on the door speaker. If you find that the bass doesn't come from the speaker, just tune it carefully as mentioned above. @219