I have a similiar problem with the logitech 930 usb 7.1 headset. The problem is the virtual 7.1 sound.
It's only emulated 7.1 and the USB soundcard/connector makes it hard to pick up the sound
without the virtual surround effects. You can try to disable 7.1. or the equalizer.
Or just dont use the USB connector. Use a normal Analog 3,5mm plug to connect.