A first playback device can include a wireless network interface, an audio input interface, one or more processors, and data storage. The data storage stores instructions that, when executed by the processors, cause the first playback device to determine a first radio frequency (RF) energy level associated with RF signal communications from a second playback device to the first playback device. The first playback device modifies a threshold RF energy level for holding off transmissions by the first playback device based on the first RF energy level. The first playback device receives multi-channel audio content via the audio input interface and detects an ambient RF energy level. Based on the ambient RF energy level and the threshold RF energy level, data that represents a channel of the multi-channel audio content is communicated by the first playback device to the second playback device for playback by the second playback device in synchrony with playback of one or more other channels of the multi-channel audio content by the first playback device.