I'm using a Megalodon Maelstrom Headset (old-ish Razer 7.1 USB). When in 7.1 mode, all the sound spatialisation is "blurry". It's sometimes even difficult to know if sounds come from the right or the left, let alone front or back.
In stereo mode, it works as expected.
Spatialised sound w/ Megalodon Maelstrom headset