Thanks for those comments!
Bruce
Theories are not so much answers as questions, to be supported or undermined by experience & testing.
Source: Calyx 24/192 DAC, tweaked laptop w/JRMC. Amplification: Pass DIY B1rev2 pre, Classe Audio 70. Loudspeakers: Proac Response 1sc. Cables/stands: spkr MIT MH-750 / HT Truthlink XLR, Vampire AI2, RFC Pluto, heavy sand-filled Target stands for speakers and Hi-Fi. Bass traps in corners, acoustic panels at first reflection points. Isolation: Roller bearings & cups, inner tubes. Mains: Balanced power transformer feeding hydra mains block.