The frequency response differs (17 - 23,000 Hz vs 20 Hz - 20000 Hz), which can influence how well the headphones reproduce lows, mids, and highs. Sennheiser CX 275s and Urbanears Sumpan offer different noise cancellation capabilities (No vs NA), which can impact how effectively they block external noise. Both models support modern Bluetooth connectivity, ensuring stable wireless performance with compatible devices. The driver size differs between the two (NA vs 13.6 mm), which can influence sound depth, bass response, and overall audio clarity. There is a noticeable difference in weight (15g vs NA), which may affect comfort during extended use. Impedance levels vary (16 ohms vs 32 Ohms), which can affect compatibility and audio output when used with different devices. Both headphones offer solid battery performance, making them suitable for long listening sessions and travel. Overall, both headphones are feature-rich and cater to users looking for a combination of sound quality, comfort, and wireless convenience. If you're comparing Sennheiser CX 275s and Urbanears Sumpan, both models offer a strong combination of sound performance, comfort, and modern wireless features.

Verdict: Choosing between Sennheiser CX 275s and Urbanears Sumpan depends on whether you value better sound, longer battery life, or enhanced features.