From a usability standpoint, both models provide a reliable and premium headphone experience. There is a noticeable difference in weight (388 g vs 260 Gm), which may affect comfort during extended use. Both models support modern Bluetooth connectivity, ensuring stable wireless performance with compatible devices. The driver size differs between the two (45 mm vs 38 mm), which can influence sound depth, bass response, and overall audio clarity. Both headphones offer solid battery performance, making them suitable for long listening sessions and travel. Impedance levels vary (250 Ohms vs 300 ohm), which can affect compatibility and audio output when used with different devices. Beyerdynamic DT 1770 PRO and Sennheiser HD 660S2 are well-known options in the wireless headphone segment, offering a balance of audio quality, battery performance, and smart features. The frequency response differs (5 Hz - 40000 Hz vs 8 Hz -41500 Hz), which can influence how well the headphones reproduce lows, mids, and highs. Beyerdynamic DT 1770 PRO and Sennheiser HD 660S2 offer different noise cancellation capabilities (NA vs AMBIENT), which can impact how effectively they block external noise.

Verdict: Choosing between Beyerdynamic DT 1770 PRO and Sennheiser HD 660S2 depends on whether you value better sound, longer battery life, or enhanced features.