Interesting... I have a Logitech Z906 5.1 sound system connected to a Realtec Sound Blaster (set to 5.1 surround). The Z906 features a possibility to mix stereo to multi channel, but that is enabled so the sound I get is what the sound card delivers. Since my "spotters" voice comes through center speaker only (no mistake possible) and while in pits without engine running I can distinctly hear air guns, other tool sounds, people talking, engines, birds ... coming from left - right - front - rear .... How would that be possible without surround sound ? I did notice that dedicated sounds are not always coming from the right direction, e.g. tire scrubbing (Formula trainer) which comes from the front speakers while blocking the rears...engine sounds from the front too... Maybe my conclusion is wrong, but even hearing the spotter through the center speaker only lets me think there is more than 'just stereo' ? No ?