Might consider using the 2801 to power the highs for your speakers and the 'sub' out from the 2801 into the Yamaha to power the lows.Imo, it's not a good idea, you don't want to use a active crossover in the receiver and the passive crossover in the speakers at the same time.
Use a pair of 'Y' rca cable connect the FRONT R/L pre-out to both power amp input.
https://ae01.alicdn.com/kf/HTB14A.3RpXXXXa6XVXXq6xXFXXXU/ATAUDIO-HIFI-Single-RCA-to-Dual-RCA-Subwoof...