Bang & Olufsen - Beoplay HX vs Sennheiser - HD 660S2

The Beoplay HX edges ahead on the Mars Score (68.3 vs 64.2), but the 4.1-point gap is small enough that the right pick comes down to which spec advantages matter to you.

Pick the Beoplay HX if your top frustration with your current device is running out of charge before the day ends — endurance is the lead spec here. The biggest gaps in its favor are active noise cancellation, multipoint, battery life.

Pick the HD 660S2 if you carry the device everywhere and weight or thickness has been the deciding factor before. Its strongest claims are weight, driver size.

Both ship with comparable spatial audio, ldac, water resistance, so those specs don't separate the two — focus on the differences below.

Bottom line: there is no wrong answer here — match the spec advantages to how you actually use the product. The Mars Score parity tells you both are well-rounded; the differences are about trade-offs, not quality.