Forte 4A vs Monarchy SM-70 (std model) in bridged mode

I heard the Forte 4A and purchased the Monarchy SM-70s; there was no comparison. I used two in bridged mode as monoblocks and with speakers like my Von Schweikert they were terrific. Once I switched to high efficiency speakers, the noise floor was a little too high, even though they still sounded great.

I'd choose another Monarchy for your biamping.