Question about Klipsch R-51M

Yes, of course, the R-51M are connected to a receiver. If the receiver supports at least 5.1 (which most of them do anyway), you can simply connect the speakers to the other outputs on the receiver. Normally, however, you choose 2 floorstanding speakers and 2 bookshelf speakers + 1 subwoofer for a 5.1 setup, but 4x bookshelf speakers + subwoofer will also do for smaller rooms.