Sennheiser HD 660S Open-Back Headphones Leave a Comment / Uncategorized / By Alden / January 6, 2022 94 GEARANK 94 out of 100. Incorporating 1900+ ratings and reviews. Street Price: $499.95 Manufacturer: Sennheiser Product Links: ManualWarranty (2 Years) Gearank High Notes 2022.01: Highest Rated Studio Headphones Under $500