Question about Klipsch R-100SW

This is an active subwoofer. It does not have an Ohm rating as it is self-powered (via the supplied mains cable) and does not draw power from an amplifier (no connection with speaker cable).

You can only connect low level inputs to it (for example 2 x RCA red and white from pre out, or an LFE cable from subwoofer out). In contrast, there are passive speakers/subwoofers to which you can connect high level inputs. These then have resistance specifications (ohms).