In summary, in TWS earphones, ANC and premium sound are becoming must-have features. Those who do not design for both risk poor acceptance in the market. A hybrid driver system consisting of a dynamic woofer and Knowles balanced armature tweeter give the acoustic designer plenty of headroom for meeting both bass and treble requirements. The Knowles KN1 reference design TWS earphone provides a benchmark for sound quality and ANC performance using a hybrid driver system.