rock or music with strong sense of rhythm. Cooking machine means that the stability of sound quality needs a period of use. If you listen to it for 1 hour every day, the sound will basically stabilize after 4-5 months. Harman Kardon Glass 3 is suitable for rock or music with strong rhythm in the second stage. Harman Kardon is a division of Harman International Industry, specializing in the production and manufacture of home and car stereos.