In my office system I run Harbeth LS35a s with a Tektron 300b SET amplifer (Linn Ikemi and Logitech internet radio/server as sources). The space is quite small maybe 10 x 12 ft. I rarely go past 1/3 volume and it has plenty of power. The sound is beautiful to my ears. Obviously not as much clout and bass as a heavy duty system but that's nit the point - hard to beat for an aria!
