I’ve heard many models from Line Magnetic paired with many different speakers; and I owned the big LM219 (predecessor of your 845) and tried it with some different speakers as well. The best results were always achieved with high efficiency speakers (easy to drive) like Omega, Zu, Audio Note and Tannoy.
Recommendations for speakers that sound great at lower volume levels.
I have a pair of Harbeth SHL5 Plus and they sound wonderful when I crank them up. But at moderate to low volume levels they sound disappointingly flat and unengaging - instruments are less palpable, bass has less bloom, and soundstage has less air and dimensionality. I drive my speakers with a tube integrated - a Line Magnetic 845 rated at 26 watts of power. My Harbeths are rated at 86db. Would a higher sensitivity speaker be helpful? Or how about a good quality small shoebox sized pair of speakers coupled with a subwoofer? Or not. What speakers are going to deliver music you can feel at low volume levels? What say all you wisened audiophiles?