There is a noticeable difference in weight (225 g vs NA), which may affect comfort during extended use. The driver size differs between the two (40mm Dynam vs 40 mm), which can influence sound depth, bass response, and overall audio clarity. Impedance levels vary (24 Ohms vs 35 Ohms), 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. The frequency response differs (3 - 100,000Hz vs 10 Hz - 25000 Hz), which can influence how well the headphones reproduce lows, mids, and highs. If you're comparing Sony MDR-1A-B and Koss Pro4s, both models offer a strong combination of sound performance, comfort, and modern wireless features. From a usability standpoint, both models provide a reliable and premium headphone experience. Both models feature noise cancellation, helping reduce background noise for a more immersive listening experience. Both headphones offer solid battery performance, making them suitable for long listening sessions and travel.

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