B&W 805 diamond vs 805D2

Hi, I've been reading these forums for a while but decided to finally register.

I want to buy a set of B&W 805 speakers. Does anyone here know the difference between the first diamond series and the 2nd diamond series? I have been searching the web for days to get an answer to this question but I can't find an answer anywhere!

Differences between other versions (nautilus, signature, d3) are quite clear!