The frequency response differs (20 Hz - 20000 Hz vs 10 - 30.000 Hz), which can influence how well the headphones reproduce lows, mids, and highs. If you're comparing Koss QZ900 and Beyerdynamic DT 287 PV MK II, both models offer a strong combination of sound performance, comfort, and modern wireless features. Overall, both headphones are feature-rich and cater to users looking for a combination of sound quality, comfort, and wireless convenience. Koss QZ900 and Beyerdynamic DT 287 PV MK II offer different noise cancellation capabilities (Yes vs NA), which can impact how effectively they block external noise. Both headphones offer solid battery performance, making them suitable for long listening sessions and travel. Impedance levels vary (32 Ohms vs 250 ohm), which can affect compatibility and audio output when used with different devices. Both headphones are equipped with capable drivers that deliver balanced sound output suitable for music, calls, and entertainment. Both models support modern Bluetooth connectivity, ensuring stable wireless performance with compatible devices. There is a noticeable difference in weight (NA vs 240 g), which may affect comfort during extended use.

Verdict: Both headphones offer strong performance, and the right choice depends on your priorities such as battery life, comfort, and noise cancellation.