There is a noticeable difference in weight (NA vs 10.5 Gm), which may affect comfort during extended use. From a usability standpoint, both models provide a reliable and premium headphone experience. The frequency response differs (40 Hz - 20000 Hz vs 5 Hz -40000 Hz), which can influence how well the headphones reproduce lows, mids, and highs. The driver size differs between the two (NA vs 11.5 mm), which can influence sound depth, bass response, and overall audio clarity. 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. Both models feature noise cancellation, helping reduce background noise for a more immersive listening experience. Sennheiser IE 4 and Denon AH-C820 are premium wireless headphones designed to deliver high-quality sound along with advanced features like noise cancellation and long battery life. Impedance levels vary (32 Ohms vs 16 ohm), which can affect compatibility and audio output when used with different devices.

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