New room, 12'x17'

I am thinking of planning a room within a room in my basement. I like my current setup but am considering a projection video system. It would mean constructing a partition and the space would be 12' x 17'. The screen and seating would be 17' from each other and the screen and speakers would be on the short wall. My problem is this: I am concerned that I will degrade the sound of my two channel system and music is more important than video. Are any of you using a 12'x17' room for 2 channel? How do you like it and how are your speakers positioned? I am using Von Schweikert VR-4JRs plus other VSA speakers for the surround modes. The screen will be 100-120" diagonal, taking up most of the wall. I'm not sure I want to do this if it makes 2 channel worse, but who knows, it may be better! Thanks in advance for your opinions.
I would think the way you want to set it up is fine. Just try to leave some room behind the listening area and not use high back chairs.
Why not use a drop down screen and keep your space? I would guess that you've taken some time and care to assemble your system in its current 17x25 space, which is a nicely sized room. This way you also don't duplicate your front speakers and you can start with a phantom center. There seems to be mixed opinions on the necessity of a center channel and the quality of sound (i.e for movies you need it for the dialogue vs. the problem of lobbing and screwing up the sound of the left and right). In any event, you could start with an inexpensive manual pull down to test, which is still far less work/cost than building a partition.

Those are my thoughts now. Rather than mess up a good thing I should use methods to control ambient light. I will have to deal with a projector hanging from the ceiling and running wires. 2 channel is just too important. My wife has agreed on a motorized screen and window coverings now that I brought up remodeling! I only use the front half of the 17' x 28' room. Behind me is a 7' Baldwin grand and bookshelves. I prefer having space behind me and more near field listening. Like a prefer 15 rows back and center at Powell Symphony Hall. Nice ambience. Thanks for your input.