How many preamp outputs does your HU have? If it only has 1 pair then you are wasting your money getting 2 pairs of RCAs, you will not be able to plug one of the pairs in. If you have 2 pairs of outputs then you might want to run the two pairs of RCAs just so you have flexability in the future in case you want to eventually run 1 pair of speakers and a sub or 2 pairs of speakers. If you want to be cheap, just get one pair of RCAs and split them at the end.
