An audio system including a first microphone-equipped playback device and a second microphone-equipped playback device. The audio system is configured to synchronize playing of audio to a listener position by receiving by the first microphone-equipped playback device an audio stream, and playing the audio stream on a speaker of the first microphone-equipped playback device, in accordance with a playback delay Δt. The playback delay Δt is in accordance with a first calibration sound originating at the listening position, a second calibration sound originating at the second microphone-equipped playback device, and a third calibration sound originating at the first microphone-equipped playback device.