Sennheiser CX 400BT review: Audiophile-grade true wireless buds under $200Staff·November 24, 2020Audio Gadget ReviewsNews & ReviewsReviews The first pair of standalone earbuds I bought was the Sennheiser CX 400-II. It was 2009 and at the time, it seemed preposterous to spend money on an Source: Sennheiser CX 400BT review: Audiophile-grade true wireless buds under $200