Maybe they had the speakers connected out of phase with each other part of the time? I'm only partly joking :-)
Also, the impedance characteristics of the speakers, assuming they are similar to what was measured in this 2003 Stereophile review (see the graph near the bottom of the page), could conceivably result in poor performance (specifically including weak bass and a messy midrange) if the wrong output tap on the amp had been chosen. Given those impedance characteristics, choosing the 8 ohm tap, rather than the 2 or 4 ohm tap, would change the sound in those directions, although I have no idea to what degree.
Regards,
-- Al
Also, the impedance characteristics of the speakers, assuming they are similar to what was measured in this 2003 Stereophile review (see the graph near the bottom of the page), could conceivably result in poor performance (specifically including weak bass and a messy midrange) if the wrong output tap on the amp had been chosen. Given those impedance characteristics, choosing the 8 ohm tap, rather than the 2 or 4 ohm tap, would change the sound in those directions, although I have no idea to what degree.
Regards,
-- Al