Stereo audio can be either balanced or unbalanced, depending on how the audio signal is transmitted. If stereo uses a three-wire system (two signal wires and a ground wire), then it's balanced, but if it uses a two-wire system (one signal wire and a ground wire) to transmit the audio signal, then it will become unbalanced. It's important to note that just because audio is in stereo, it doesn't necessarily mean it's balanced.