1) Sub-bass affected
The bottom end of the frequency range (15-35hz) was noticable different. With LFE enabled, the pitch with higher. Not a lot higher, but still higher.
2) A noticable artiface in the upper frequency range
The bottom end was also a lot 'cleaner' with LFE disabled on the soundstorm - there is a noticable hiss in the upper range when playing low bass notes. With LFE disable, that disappears.
3) A large hole in the responce
With LFE enable on the soundstorm, there is a huge dip in responce the 100hz region. If i set the cross-over to 50hz it's better, but if i set the cross-over to 80hz or above there is a big problem. I always though it was a problem with my sub/sat setup on my amp, but when disabling LFE on the soundstorm there is a huge imporvement in that area. Again, in theory this shouldnt even be happening.
4) A problem with stereo imaging
I have found that when running with or without DD encoing selected the LFE channel effected seperation on the two front channels. When you move the slider up through the range (towards 500hz) there is a sharp drop in seperation between the two channels. Try it when listening to any music which makes heavy use of both channels. Move the slider up, and it almost becomes a mono recording.
How much difference this would make to the average pc user i dont know - there aren't many pc speakers than can reproduce audio below 35hz with any real snap anyway, and stereo imaging isn't a great importance with any set of pc speakers. Still, it seems odd to me that there is a difference at all - there shouldn't be in theory and it sounds a hell of a lot better with DD and LFE off altogether.