There is a noticeable difference in weight (205 g vs 274 gm), which may affect comfort during extended use. Both models feature noise cancellation, helping reduce background noise for a more immersive listening experience. The frequency response differs (20 - 20,000Hz vs 20 Hz - 20000 kHz), which can influence how well the headphones reproduce lows, mids, and highs. Both headphones offer solid battery performance, making them suitable for long listening sessions and travel. From a usability standpoint, both models provide a reliable and premium headphone experience. Impedance levels vary (32 Ohms vs 32 ohm), which can affect compatibility and audio output when used with different devices. If you're comparing JBL Synchros E40 BT and JBL Quantum 400, both models offer a strong combination of sound performance, comfort, and modern wireless features. The driver size differs between the two (40 mm vs 50 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.

Verdict: Choosing between JBL Synchros E40 BT and JBL Quantum 400 depends on whether you value better sound, longer battery life, or enhanced features.