Another vote for Google Mesh. You need two of these, first Mesh will be hard wired to your router and second Mesh hard wired to Innous Server. The Mesh app is superb, one feature I really like is, you can prioritize the device for maximum bandwidth.
Please stay away from any power line based range extenders, you will be introducing unnecessary noise in your audio system.
Please stay away from any power line based range extenders, you will be introducing unnecessary noise in your audio system.