A:AnswerHello Spar,
Yes, the separation is limited by the cable, however, you may purchase a longer cable if necessary for your setup. The included cable is a 6' single RCA to single RCA to connect the left speaker to the right speaker.
A:AnswerHi there, yes, you can connect these M1 Bookshelf Speakers to the Empire via the RCA output. This would need to be a wired connection, as the Empire is a Bluetooth receiver (you can stream music from your Bluetooth-enabled device TO it, but not from it). Thanks for your question!