As Newbee Stated: A source with 1/3d octave tones is most beneficial when setting up a sub/main system. The Stereophile Test CD 2 contains all three decades. Time alignment is ALWAYS critical. My Tact 2.2X allows placement of the subs in the corners of the room(which unloads them dramatically), delays the mains(time aligns), and equalizes the responses(within .5db). The realism is outstanding.
