slat wall cavity

Hi all, I received some direction from Glenn about the construction of the slat wall in my studio build which is now under way, as shown in the photo. The cavity has been constructed from 3/4" plywood and front framing is 2x4 studs. We sectioned off the cavity vertically and also another section to allow access to the water meter. After sealing with acoustical caulking, I will friction fit 1" rigid 3 lbs/cu.ft., two sheets deep, in the framing on the studio side and cover with fabric, then apply the wood slats. Because the rigid is 24"x48" sheets, my contractor elected to build the framing using 12" centres...so he figured, just cut them in half width-wise. He was also thinking that it would provide more support for the slats. I hope this doesn't present a problem with the slats doing their job. My question is, am I correct in interpreting that there is no treatment on the inside of the slat cavity (meaning insulation) and that the plywood should be left bare? All of the illustrations that I have seen show no material at all on the inside of the cavity, i.e. back, sides, top or bottom. Thanks guys Alan

lightly fill the remaining space behind the rigid insulation with pink (wall) insulation. as a general rule using 24" o.c. is typical but i don't think the 12" o.c. will be a problem. the plywood can be stained, painted, varnished, oiled etc as you desire to finish it. the plywood is a bit more absorptive when untreated.

Thanks very much Glenn. This is exciting. We're actually starting to build this thing!! Actually, I didn't think that the plywood needed any coating, being hidden from view and all. I'll advise my construction buddy of your suggestions and leave part that up to him. I see that I need to learn how to better use this forum. Not really familiar with bumping and all that stuff, and I noticed that someone else was advised to just use one thread for Q & A and so on. I'll start a "build diary" to use during construction. Referencing all of the other build diaries has really been helpful. Hopefully, my build will help others embarking on this journey as well :D