What is ground loop hum?

When there is a voltage difference between the frames of devices, voltage and current flow from the frame of the device with the higher voltage to the frame with the lower voltage. This phenomenon that occurs as the frames of audio devices form a common voltage is called ground loop noise.

In other words, the chassis of all devices are electrically connected to each other and linked by a single wire. Essentially, all audio products are connected by cables.

Due to the voltage difference between frames, voltage and current move, and the strength of the magnetic field changes proportionally to the flow and amount of voltage. This causes a humming sound from the speakers, known as loop hum.