Sonus Faber Cremona - which Ohm tap do you like?

[Grasshopper]

I bought a pair of new to me Sonus Faber Cremonas earlier this month.

This week, I brought home a McIntosh MAC6700 integrated. (After messing with a fellow AA member’s MA5200. At only 100wpc, and no autoformers I didn’t expect much, but it sounded awesome!!!)

Reading the speaker specs, they are a nominal 4 ohm speaker.

My first connection to the amp I connected them to the 4 ohm tap. The sound was anemic at best. Missing dynamics, flat, and totally underwhelming. It was also noticeably bright. Nothing like the cheaper ma5200—I was very disappointed.

I had read somewhere that Sumiko prefers the 8 ohm tap with sonus/McIntosh combinations, so I gave the 8 ohm tap a try.

Holy smokes, night and day difference. Better in every way. Better bass, dynamics, etc.

What gives? Why would a “nominal 4 ohm speaker” sound better on the 8 ohm tap?

Thoughts?