71 headset usb headset stereo pc headset design over ear types dynamic closed transmission mode cable types of connection usb usb 20 type of cable single sided sound modes 71 software surround headset type of headphones headband features padded headband adjustable headband volume control in line control passive noise cancellation function mute sound systems dolby headphone dolby prologic iix headphone transmission range 20 20000 hz headphone i