A system, including: a computing device that executes an interactive application and generates and transmits image frames; a head-mounted display (HMD) that receives and presents the image frames, wherein the HMD includes a magnetic emitter that emits a magnetic signal having a synchronization encoding synchronized to the received image frames; a controller device that includes a magnetic sensor that detects the magnetic signal, wherein the controller device processes the detected magnetic signal to determine magnetic position data and read the synchronization encoding, wherein the controller device uses the synchronization encoding to generate corresponding timing data indicating a timing of the magnetic position data based on the synchronization encoding, wherein the controller device transmits the magnetic position data and the corresponding timing data to the computing device; wherein the computing device uses the magnetic position data and the corresponding timing data to determine the location and/or orientation of the controller device.