Headphones headphoneSennheiser HD 660S2 Review (2026): The Modern 300Ω Upgrade★ ★ ★ ★ ★ 4.7/5The Sennheiser HD 660S2 fixes the HD 650's two weaknesses — sub-bass and treble roll-off — for $170 more. Whether that …$499Apr 21, 2026
