McIntosh bridged MC152s vs MC312


Jan 11, 2022
Hey everyone, I have a fairly random, but I think straight forward question about McIntosh amplifiers. I currently own a pair of McIntosh MC152 stereo amps (150W/Ch.). They drive two different sets of speakers in two different rooms. I don’t have any current plans to change my set-up, but I’d like to understand my equipment a little better. They are both bridgeable and can run as monoblocks. My general understanding is that when an amp runs bridged, it doubles the wattage, and halves the impedance. Theoretically this would result in 4 times the wattage, but apparently only achieves about triple in practice. This would theoretically offer 350 W/Ch. from my amps if they were running mono, but to my understanding McIntosh and their proprietary autoformer taps deliver the same wattage into each tap. I’m also under the impression that by bridging the amp and halving the impedance, it can put a lot more strain on the amp by dipping super low (depending on the speakers). So my question is this:
1) Which tap would I use if running bridged? Half the impedance of my speaker? And…
2) Would a 300 W/Ch. stereo amp like the MC312 have an easier time driving difficult speakers because it sees double the impedance?

Thanks in advance