MB Quart QSD 164 170 Watt Midrange Mid Woofer Component Car Speakers with X OverMB Quart QSD 164 6. 5" 17cm 170 Watt Midrange Mid Woofer Component Car Speakers with Single X Over If you're a stickler for top performance, MB Quart's Q Line QSD216 6 3 4" component speaker system will meet your demands. For more than 30 years, MB Quart has pioneered car audio, designing speakers that create an ideal listening environment in almost any car. The result? MB Quart equipped cars have won more international car hi fi competitions than any