The HE-500 and the LCD-2 are both very good headphones. Doh. Some say they are quite similar. Yes; if compared to e.g. the AKG K701. No; if comparing the HE-500 and LCD-2 only towards each other. No headphone performs the best on every parameter, but all headphones shine on some parameters. Often, choosing a headphone is like selecting a good compromise. This ain't a competion of which headphone is the "best". It is all up to the readers on subject forum to interpret the usefull info and filter out the competition statements. As far as the HE-6 goes into this context: The HE-6 is so different to both the HE-500 and the LCD-2 that it is actually no use in comparing the latter two to the HE-6.
Sometimes the LCD-2 shines. Sometimes the HE-500. If they indeed were so similar as some other threads indicate - I would have sold one of them, but have no plans in doing so.
tl;dr: If you don't quite like the LCD-2? Try the HE-500. If you HATE the LCD-2? The HE-500 is not your next headphone either.
Edited by Loevhagen - 12/20/11 at 9:08am