About a month ago, I started this thread and my intent was to gain input for ideas on improving the system that we use for movie watching in our family room. I have a separate 2-channel room on the other side of the house that I use for the best possible listening experience with my music collection. Our family room is used primarily for entertaining and relaxing, and sound quality is not the main priority in this room. (WAF outweighs speaker selection, acoustic treatment, etc.)
I received lots of great advice from members of this forum and I incorporated many of them in the upgrades to this room. I am happy to report that the changes that were made produced a dramatically better-sounding experience in the room, while still maintaining an acceptable WAF level. I am 100% happy with the final outcome! The changes are outlined below.
1. I replaced my mismatched set of front speakers with a set of three new Paradigm Foundation Series 70 LCR speakers. I listened to them against numerous other speakers and found them to be the right solution for my room. I needed bookshelf-style speakers mounted on stands (so that the sound could be projected over the two couches in the room). These speakers are as large as I felt going to for this setup. I tested them against several full-sized floor-standing speakers and I was impressed with their full range sound. Most importantly, I received the major improvement in center channel sound that I sought when I started this project. Secondarily, I was also able to have all three speakers match each other exactly.
2. I added a REL 7Tx subwoofer. I listened to several different subs but selected the REL for several reasons including extremely high build quality, ability to Hi/Lo wire to my center channel for added low-end, and the ability to also simultaneously utilize its LFE channel for additional low-end support during certain movie scenes. I also still have my large Polk sub in the corner of the room for additional LFE support as well.
3. I moved my Front Presence speakers down on the front wall by about 4'. They are now within the tolerance of the diagram shown above by kota1. This has made a big difference. That little adjustment now allows me to hear those speakers, where before I never heard them at all.
4. I moved my Front Right speaker over toward the center of the room to a position that is symmetrical with my Front Left channel and within the 22-30 degree recommended positions for front speakers. I had moved that speaker over to the far corner because my wife never liked the way it looked sitting near the fireplace. My concession is: we slide it over (I put felt slides on the bottom of the speaker stand) to the correct position when we are watching a movie then I slide it back on the outside of the fireplace when we are not watching a movie. The room looks best when it's in the corner, and the sound is best when it's in its correct position so this process is an easy solution. (I placed a couple of marks on the fireplace hearth to show the exact correct position and angle.)
Lastly, I ran the YPAO room calibration after everything was in its final place and I experimented with adjusting subwoofers, speaker size, etc. In the end, I increased the Center Channel volume by about 1.5 dB so that we can both hear dialogue clearly without having to use CC.
I'm happy to report that we are back to watching a movie together every night in this room, and most importantly my wife says she loves the new sound system. The biggest changes are major improvements to the sound quality from my center channel and to the sound stage that you feel in the two main listening positions.
I'm guessing I will be ready for the next upgrade in about two years' time. At that point, I will tackle installing two pairs of speakers in the 20' high ceiling while also introducing a new processor to the system. For now, it's time to watch lots of movies!
Thank you to everyone that provided input, I used lots of groupthink for the changes that were made. This forum is a tremendous resource.