I’m going to experiment with some bass traps in the corners - cylinder, wedge, etc., but I think a 15’ equilateral triangle speaker placement and listening position is a challenge for most speakers, even not considering the very high ceiling. Rethinking the overall situation, I think I’m better off to leave the large family room set up as is, with some room acoustics improvements and focus on the living room where I now have the BP20s. That room is 13’x17’ with 8’ ceiling and much more suitable for music listening and allows for a lot of speaker options. A pair of medium size stand mount monitors will be perfect for that room, maybe a pair of used Aerial 5Ts. Thank you all again for all your input.
Anyone tried these guys for room treatment options?