So I have a pair of KRK Rokit 5 G2 speakers and I want to buy a Dayton Audio 12" Subwoofer, but the Dayton Sub doesn't have RCA outputs to connect to the KRK speakers. I want to use the crossover on the sub, so could I just run an RCA to speaker cable connection from my soundcard to the sub and a speaker cable to RCA connection from the sub to the KRK speakers? If not is there someway I can connect the speakers to the sub without having to buy a receiver?
The subwoofer does not have a high pass filter associated with the speaker level inputs or outputs. So you should just connect the monitors to your sound card. If you don't want to use the sub out of the card then just split the output to both the sub and the monitors in parallel. Then you are using the low pass crossover of the sub. No receiver needed.
I have a Native Instruments Audio 6 as my soundcard, so it has no dedicated sub out just rca outputs. The KRK monitors are advertised to reach down to 52hz, so if I run parallel output to both my KRK monitors and my subwoofer would turning the crossover on the sub down to 50hz sound balanced. Or would it be wise to invest in an external crossover or receiver with a hi pass filter to ease some of the low end load on the KRK monitors?