the Yamaha AVR, even in pure direct mode, appears to be adding some noise to the sound
What I been sayin’. The only way of doing HT at Encore level is to run stereo, plugging HDMI video directly into your monitor.
Those are some fine speakers. I know, because my Moab are awesome and Encore have to be at least that good. So even more awesome.
My suggestion would be to ditch separates, and all the extra multi-channel stuff, in favor of a Raven Osprey. Then not only your son but your wife too will be joining you and you can all sit there slack-jawed in awe of how good those Encores sound with some quality tube watts running through them. https://www.ravenaudio.com/product/osprey-mk3/