What's in the box? HD 350 BT Wireless headphones USB-C charging cable Quick Guide Safety Guide Technical Data Frequency response (Microphone) 80 Hz to 6,000 Hz (-3 dB) THD, total harmonic distortion < 0.3 % (1 kHz, 100 dB) Transducer principle Dynamic, closed Pick-up pattern Dual Beamforming Transducer principle (Microphone) MEMS Bluetooth Version 5.0 Frequency response 18 Hz to 22,000 Hz (-10 dB) Modulation scheme GFSK, π/4 DQPSK, 8DPSK Battery Specification Built-in Lithium-Polymer rechargeable battery: 3.7 V ⎓, 300mAh Charging Current 320 mA max. App support EQ and updates via Sennheiser Smart Control Audio codec SBC, AAC, AptX™, AptX™ Low Latency Supported Profiles HSP, HFP, AVRCP, A2DP Charging time Approx. 2 hours Charging voltage 5 V, DC Ear coupling Around Ear Operating time 30 hours music playback via Bluetooth Sound pressure level (SPL) 108 dB (1 kHz/0 dBFS) Transmission frequency 2,402 MHz to 2,480 MHz Weight Approx. 238 g
