Key Differences

Both headphones offer solid battery performance, making them suitable for long listening sessions and travel. In general, both options are suitable for everyday use including music, calls, travel, and work-from-home scenarios. The driver size differs between the two (38 mm vs 45 mm), which can influence sound depth, bass response, and overall audio clarity. There is a noticeable difference in weight (260 Gm vs 376 GM), which may affect comfort during extended use. Sennheiser HD 660S2 and Beyerdynamic DT 1990 PRO MKII offer different noise cancellation capabilities (AMBIENT vs NA), which can impact how effectively they block external noise. Impedance levels vary (300 ohm vs 30 ohm), which can affect compatibility and audio output when used with different devices. Both models support modern Bluetooth connectivity, ensuring stable wireless performance with compatible devices. Sennheiser HD 660S2 and Beyerdynamic DT 1990 PRO MKII are premium wireless headphones designed to deliver high-quality sound along with advanced features like noise cancellation and long battery life. The frequency response differs (8 Hz -41500 Hz vs 5Hz - 40KHz), which can influence how well the headphones reproduce lows, mids, and highs.

Verdict: Both models are competitive, and your decision should be based on your usage needs and preferred features.