I do have Shahinian Diapason speakers, which consist of a module with drivers for the middles and highs as a 2-ohm-load, and a subwoofer as a load of 4 ohms - together a 6-ohm -load. I tried everything with my MC402: connecting the module to the 2-own-tap, and the sub to 4 ohms, both unit-wires to the 4-ohm-tap, both to the 8-ohm-tap. McIntosh told me to go with the 4-ohm-tap, too, but still the 8-ohm-tap was clearly the best, and indeed I heard it right away: More power, more speed, better bass. Interestingly enough, although McIntosh claims that all taps sound the same, Joachim Pfeiffer, the reviewer of Audio magazine in Germany who has reviewed a lot of McIntosh amps, says that you always end up better with the 8-ohm-tap. In his last review of the MC402, he wrote that so far he never found a speaker sounding better on the 4-ohm-tap. However, only hearing is believing.
