YST-SD90Speaker System / 1991
This speaker system offers a powerful bass sound despite its size thanks to Yamaha Active Servo Technology (YST). Featuring YST-SDS90 speakers and the YST-A90DC amp, only 200 sets were made worldwide. The YST-SDS90 speakers were finished by hand.
The YST-SD90 was selected for New York's Museum of Modern Art permanent collection.