Great to see you are still hanging around this old 950 forum Gonk. I'm sure you'll have an answer for this one, and i'm sure its been asked before !

I'm starting to hook up all my components again and i've come across a stumbling block. When i last had my system running, it was a 5.1 system. My new system is 7.1 and the 950's outputs in this regard are where my confusion starts.
I have always run the 950's amp outs through an ICBM before the amplifiers and there the issue starts.
The ICBM wants me to combine these inputs and outputs with extra Y adapters which will combine to give 2 mono signals (essentially 6.1).
So if the 950's rear surrounds outputs are discrete, i surely would not want to do this, right? Unless of course the 950 does NOT treat these discretely.
I'm thinking that although I've always left analog bass management off in the 950, and let the ICBM handle it, I may have to engage it and use it to control these two speakers.

Ok, I think i've answered my own question. The analog bass management is immaterial in this regard as it is only 5.1, so i can leave it off and use the ICBM as I always did. The High pass crossover and output level control within the 950 should do what i need, so i will not use the ICBM with these speakers.
Of course it is all moot now, but why did they make the ICBM 6.2? - Love the .2 though !

I think you're on the right track here: the multichannel analog input is 5.1 only, so you aren't going to have a 7.1 analog source to deal with.

If you have a 7.2 setup and want to use the ICBM to create discrete left and right subs, you could use the 950's internal bass management to handle the surround channels (all four of them) and possibly even the center, then set the fronts to large and steer the front pre-outs and sub pre-out through the ICBM-1.

The ICBM was developed prior to the appearance of Pro Logic IIx. At the time, most systems were 5.1 and the few that were going beyond that were using Dolby Digital EX or similar processing to create a mono back surround channel. At the time, it was a practical choice to implement 6.2.