Just got my set of Elac speakers. They sound *amazing* — aside from one small issue. I have banana plugs on all the wires into the Elacs. It works great on all of them, but for the C5, it’s just not working. I’ve rechecked, re-seated, and even replaced the plugs at both ends, but it still won’t hold a connection. Is it possible there’s an issue at the binding posts, or is it more likely that these particular plugs are just “loose”? Any suggestions welcomed.