I don't know. I would have to actually *listen* to your setup. DIY is all well and good, but many folks want to have a professionally finished system as they don't have the time or inclination to do these things for themselves. This doesn't mean that one needs to hire a theater designer, but rather, with the right speakers/amplification and a good room, folks can have a great audio experience.
I see that you put a lot of thought and time into your system and I'm sure it sounds very nice. If you need help with the wire management, please let me know. <big grin>.
It is my wife's system. She was the instigator. No speaker boxes allowed. I had not really considered putting a system in that large open space. My wife insisted. As I thought about it and looked around, I saw no integrated product that would meet our requirements on numerous counts.
It was a complex design problem. It was made possible by being new constriction. By filling in the space between the kitchen and fireplace breast it was possible to get everything in wall. That space in only suitable fro 2.1 or 3.1. So 3.1 it was. As always the design and development of the center speaker was the most difficult. In order to be acceptable, this had to be either a coaxial or three way. Sideways MTM has to be ruled out, like a TV above the fireplace, which should never be done under ANY circumstances. For optimal speech discrimination, the midrange unit had to cover the whole of the speech discrimination band, which it does. This solution allowed for the system to be viewed properly gathered by the fireplace. Apart from being a first class system it had to cover the whole frequency band at power.
So a design using sealed enclosures and a TL sub was the solution. The sub is a 10" driver, but with TL loading it is highly efficient and can fill the place effortlessly and with authority with little power. The F3 of all the bass/mids is 80 Hz. So that was how it was modeled. However measurements and listening confirmed that the optimal crossover to the sub was in fact 40 Hz, due to reinforcement from the wall. This was something hard to model. All the bass/mids and midrange are isolated in their own compartments, so they do not drive each other. This should always be done in sealed designs with multiple drivers but seldom is.
My wife, my architect/interior designer daughter and I had some debate about how to finish the speakers. In the end the design for the speaker trim matching the bessel of the TV, and the equipment case trim matching the house trim won out. All the trim I made from aluminum angle. I made all the pieces and had the pieces professionally finished. Black speaker fabric was selected to match the TV. Then a white grill for the output end of the TL pipe. I think it worked out well form an aesthetic standpoint.
Power is 250 watts to each of the speakers and sub for a total of 1000 watts. I have found my wife really cranking it on occasions.
This system created a lot of interest among our friends. Before the Super Bowl, some of our friends asked if they could watch the last one at our place. Well that led to a pretty big bash. Not being huge sports fans, we had never given a Super Bowl party before. My wife and I spent a day cooking, and a good time was had by all. Even with the sound low the commentary was highly intelligible and the system was cranked for some ads as desired.
I don't know what the demand is for in wall systems. I have to tell you I have never visited a home with one installed. I have heard set ups installed in dealers show rooms from time to time and been less than impressed. I have by now though, heard numerous ghastly sound bar systems in homes.
Due to WAF I would have thought in wall systems would be more popular than they seem to be. So that is why I published the details of this system. It is open and free to all to do as they wish with. All the speaker parts are preserved in the C & C machine computer in Albany MN. The owner says he can make the parts available to any who want. The tweeter for the center is NLA, but Hiquaphon have a suitable 3/4" replacement that would require a minimal crossover mod.
What is a real keeper here though is that in wall sub, which gives up nothing to being in wall. For surround systems more of the two way speakers can be added.
Although this is a secondary system for us, we use it a lot, and have been glad we built it. So it is really a complimentary system to our 7.2.4 theater room, which we really enjoy.
You are a long way from here, but if this lock down ever ends and you are in the Twin Cities you can give it all a listen.