Is the B&K EX 442 fussy about speaker impedence?

I'm considering adding a B&K EX442 to my vintage system which contains a variety of speakers. Probably the most difficult to drive are my Ohm F's (12" Walsh driver). Does anyone have a sense of how capable the EX442 is driving power hungry speakers with a less than friendly impedence (i.e. less than 4 ohms)?

Thanks.

Jim