The frequency response differs (6 Hz - 51000 Hz vs 5 - 40 000 Hz), which can influence how well the headphones reproduce lows, mids, and highs. The driver size differs between the two (NA vs 45 mm), which can influence sound depth, bass response, and overall audio clarity. Impedance levels vary (300 Ohms vs 250 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. Both headphones offer solid battery performance, making them suitable for long listening sessions and travel. There is a noticeable difference in weight (Approx 330 g vs 370 g), which may affect comfort during extended use. Both models feature noise cancellation, helping reduce background noise for a more immersive listening experience. In general, both options are suitable for everyday use including music, calls, travel, and work-from-home scenarios. Sennheiser HD 800 and Beyerdynamic DT 1990 PRO are well-known options in the wireless headphone segment, offering a balance of audio quality, battery performance, and smart features.

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