Yes, the RCA LOW LEVEL Input is not for the Subwoofer/LFE. It is for the Center Output, which goes to the Subwoofer section of the CLR2300, which is driven by its own 150-watts amp. So your receiver will drive the High & Mid frequencies, and the CLR2300s internal amp will drive the Subwoofer frequency = Bi-Amped.
So yes, hook the Center Output of the Receiver to the CLR2300's RCA input.