Hey poges, I used these for an install of BS in a LR. Mount-It! Speaker Wall Mounts, Pair of Universal Side Clamping Bookshelf Speaker Mounting Brackets, Large or Small Speakers, 2 Mounts, 55 Lbs Capacity, Black (MI-SB37)
https://www.amazon.com/dp/B01MZE0O8U/ref=cm_sw_r_cp_api_-IbszbCMMSZR8
They worked really nice and I think jgarcia has linked them too.
My surrounds are roughly 30lbs each and I used these.
Not sure they're available still but they do allow for any articulation you'd ever need. The "mount it" ones also articulate nicely. The hardest part might be drilling into your speakers, but nobody will ever see that when mounted anyway.
Ok. .02