Moggie - When the boxes are placed in the proper position I'll have 36 inches between the boxes. I should have pictures up soon with the manifolds in position. I plan on putting an access panel door made of MDF between the two manifolds - Even if I do I mount the drivers with the baskets in the chamber I should have 18 inches between the drivers - That should give me enough room to get in there.
I haven't tried climbing through the driver holes - I'm pretty sure I wouldn't make it and would end up stuck - I have some weight I need to lose before I could manage that.
My concern is trying to get all the drywall up in that small place - I think I have a way worked out to get in in there before it is sealed up but it is going to be fun to try and move sheets around in a small space like that.
By the way Moggie, your build is one of my favorites. Amazing work you have done. I would love to try and replicate what you have done with your screen but I'm pretty sure I lack the skills to do that - I know someone that can get the Somfy motors from for cost so I may give it a try. Long ways until I get to that point though.