I'm not prepared to speak about the current status of the project as a whole, except to say that it's coming... eventually. Don't get your hopes up about anything specific. Would I like to have everything ready for next fall's football season? Yes. Do I think that could happen? Theoretically, yes. Am I willing to set any completion date? No. Not even a little.
So here's a few photos to show that I haven't burned it down. I've been trying to finalize the last of the in-wall items - particularly the HVAC, as that "should" be the last (though I keep thinking about running a few more wires for Atmos, etc. It's not too late for that, yet).
For context, let me remind you, my faithful reader, about the way this is laid out. In this image you can see the two supply ducts - 6" flex - routed through the soffits to the front of the theater, in blue. You can also see the single - 8" flex - return duct routed from the top left rear corner down through the rear wall and under the outside riser, in red. Notice also the 4" flex duct routed from the projector location to the return duct boot - this will be powered by a small 12V fan to aid in projector heat removal, via a hush box.
The return duct is the challenge. It's probably marginally too small in the first place in order to get adequate air changes per hour (I think 4 is a maximum expectation from this system - 3 is probably reasonable actual performance, and I think will be okay but not great.). Further, it get's pinched in a few places.
So let's look at the details, shall we? First, the home made boot designed to fit within the soffit and allow passage of the left supply duct. You can see in this image that the boot is a triangular prism. A rectangular prism would have allowed greater overall volume, but at the expense of further constrictions to the supply passing over it. Also, construction of a box that would mate to the wall and be reasonably held in place would have required a lot more garbage - blocking and ties and such. This was built in place with construction adhesive, sealed with caulk where required. It's not coming out, and I think it's adequate. Notice the 4" hole cut in the near face for the hush box vent.
Here we see from the outside of the theater. The primary compromise with 8" duct is that it doesn't fit within any reasonable wall cavity. In stead of running flex duct all the way to the hole cut through the wall at the top, I terminated the flex duct at the riser top, and have decided to utilize as much natural wall cavity as possible as a plenum. I acknowledge that this may become a serious soundproofing compromise, but I'm willing to live with that. It will still be possible to enhance this wall in that regard.
There's not much visible in that image, I know. Notice the staggered studs and the 1.5" furring. The wall was built on 2x6 plate, but has been extended with the furring to be about 7" total internal depth. It's not quite the 15" width stud bay you would expect with single stud construction, so it's not quite the volume I would want in order to avoid constricting airflow. It is what it is.
In the latest edition of the new red-neck workshop, I built a duct boot that would adapt from a standard 8" collar to my custom wall plenum. I have taped it to both surfaces of the wall cavity.
Then I figured it needed some duct liner and to be sealed from the adjacent wall cavities. The gaps between the staggered studs worked out pretty much perfectly to hold some 1" duct liner in there.
And one last image to provide a little more context. This wall will eventually be fitted with a small sink and base cabinet as well as some upper cabinetry of some sort - glass rack or similar, most likely. The wall cavity to the right of this one has drain plumbing already. The supply (cold only) will be plumbed in from the top of the wall.