Sennheiser HD 660S2 vs Sennheiser Momentum 4 Wireless

The Verdict

Sennheiser presents two fundamentally different philosophies here. The HD 660S2 is a wired audiophile headphone designed for critical listening with a dedicated amplifier, featuring 300-ohm impedance, handmade German construction, and open-back acoustics that deliver exceptional soundstage and detail. Its 42mm dynamic driver excels with neutral, transparent sound signature preferred by studio professionals and purists. However, it offers zero portability, requires external gear, and lacks modern conveniences entirely. The Momentum 4 Wireless takes the opposite approach, delivering 60 hours of battery life with ANC, multipoint Bluetooth 5.2 connectivity, and aptX Adaptive codec support for wireless listening anywhere. Its slightly heavier design (293g vs 260g) accommodates the battery and electronics, while the same 42mm driver adapts well to portable use. Sound personalization through the app adds flexibility for different preferences. The HD 660S2 wins for absolute sound quality and build craftsmanship if you have a dedicated listening setup. The Momentum 4 dominates for lifestyle flexibility, ANC utility, and practical all-around value at $120 less. Choose the HD 660S2 only if you're building a home audio system; otherwise, the Momentum 4 offers far better versatility and real-world usability.