That's not been on any of the feature lists, and the back panel only has one sub output. However, the ICBM will let you run stereo subs if you put it between the 950 and the 770.

I think stereo subs are a VERY useful feature (also the option to have two subs configured as front/back) and have put it onto my wish list. I was really surprised when I found out the 950 wouldn't do this, especially as the ICBM does do it.