Wow - those look great! But did you do the measurements to make sure those are at your first reflection points? 😛
And, just out of curiosity, what acoustic absorption material did you use?
You may want to consider doing a 'super chunk' style acoustic treatments in the corners. There is an easy way to find out if you'd benefit: Go stand in the corner and if the bass is significantly louder than where you sit they would be helpful. I did it in mine and noticed a very large improvement in the quality of the bass. The bass volume was significantly more even across frequencies and it removed all of the rattling I was getting. It also improved the experienced volume levels at non-optimal seating positions with no increase in volume settings at the receiver or sub.
Basically you cut triangles of the acoustic material and lay them on top of each other - typically in a frame and then wrap it with acoustically transparent fabric. They can get pretty expensive if you use Owens Corning 703 type material but I used mineral wool and I want to say it cost around $50 a corner floor to ceiling. It was more of a pain to work with as its very loose, fibrous and itchy (so mask + gloves + long sleeves) but it took less than a day to do all three of my corners (stupid door is in the fourth)
Also - very very cool!