Sennheiser HD 660S2 and Beyerdynamic DT 1770 PRO MKII offer different noise cancellation capabilities (AMBIENT vs NA), which can impact how effectively they block external noise. Sennheiser HD 660S2 and Beyerdynamic DT 1770 PRO MKII are premium wireless headphones designed to deliver high-quality sound along with advanced features like noise cancellation and long battery life. The driver size differs between the two (38 mm vs 45 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. From a usability standpoint, both models provide a reliable and premium headphone experience. Both models support modern Bluetooth connectivity, ensuring stable wireless performance with compatible devices. Impedance levels vary (300 ohm vs 30 ohm), which can affect compatibility and audio output when used with different devices. The frequency response differs (8 Hz -41500 Hz vs 5Hz - 40KHz), which can influence how well the headphones reproduce lows, mids, and highs. There is a noticeable difference in weight (260 Gm vs 377 GM), which may affect comfort during extended use.

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