Both models support modern Bluetooth connectivity, ensuring stable wireless performance with compatible devices. The frequency response differs (22 - 19500 Hz vs 20 Hz - 20000 Hz), which can influence how well the headphones reproduce lows, mids, and highs. If you're comparing Sennheiser RS-120 and Sony WI-SP510, both models offer a strong combination of sound performance, comfort, and modern wireless features. Impedance levels vary (24 ohms vs NA), which can affect compatibility and audio output when used with different devices. Both models feature noise cancellation, helping reduce background noise for a more immersive listening experience. The driver size differs between the two (NA vs 12 mm), which can influence sound depth, bass response, and overall audio clarity. There is a noticeable difference in weight (230 g vs 30 gm), which may affect comfort during extended use. Battery life varies between the two (20 - 25 hrs vs 15 Hours), which affects how long you can use them on a single charge. Overall, both headphones are feature-rich and cater to users looking for a combination of sound quality, comfort, and wireless convenience.

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