Yes, it is possible to connect both a PC and a Mac to the Edifier R1700BT speakers. Here are the details:

- The R1700BT speakers have two stereo RCA inputs, allowing you to connect two different source devices simultaneously.
- You can connect your PC and Mac using these RCA inputs, and switch between the two sources using the wireless remote control or the control buttons on the speakers.

What's more, the R1700BT speakers also support Bluetooth connection, meaning you can also connect a device via Bluetooth while having devices connected via the RCA inputs.