your subwoofers can accept high level inputs, connect speaker cable from amplifier speaker terminals directly to subwoofer inputs, 1 cable per channel. just use basic speaker cable.
when i had the rogue cronus magnum ii my subwoofers sounded much better connected to the speaker terminals. i used banana plugs for the main speakers and spade terminals for the subwoofer and the fit right on the same terminal.
worth a try. i was amazed how much better it sounded, more powerful.