new speakers 6ohm where do I connect to my MAC

Try both the 4 and 8 ohm taps. Which
ever sounds best to you. Many speakers
may publish 6 ohms but, may drop much lower.

Go with 4. I had the same question and McIntosh told mw to go with the lower value. You'll end up using the amp's total power.

A 6 Ohm load (according to McIntosh Techs) should be connected to the 8 Ohm taps.

My speakers are 6 ohms. i tried both 8 and 4 and preferred 4.

Where would you tap Martin Logan Speakers

I have an MC352 and from my experience with a 6 OHM load try both tap and use the tap that gives you the best sound. You will be able to hear the differet.

Your 2100 would probably be most happy on the 4 ohm tap. The older Macs are happiest within 80% of their tap, so 6.4 would be the minimum off the 8 ohm. The newer Macs have alot more current capability and can deal with about 20% off of their tap. The best advice has already been given, try them both, one will likely sound better. If not, use the 4 ohm so the amp will run cooler. Not all 6 ohm loads are the same. Good luck.

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.