1. Tangible, non-transitory computer-readable media having stored thereon instructions that, when executed by one or more processors, cause a computing device to perform functions comprising: receiving data indicating a first audio signal detected by a microphone of a first playback device while the first playback device is playing a second audio signal in a first playback zone; based on the first audio signal and a characteristic of the first playback device, determining an acoustic characteristic of the first playback zone by removing the characteristic of the first playback device from the first audio signal; based on the determined acoustic characteristic of the first playback zone and a predetermined audio characteristic, determining an audio processing algorithm that, when applied to audio output of a given playback device in a given playback zone that has the acoustic characteristic of the first playback zone, adjusts the audio output of the given playback device in the given playback zone to have the predetermined audio characteristic; and causing an association between the determined audio processing algorithm and the determined acoustic characteristic of the first playback zone to be stored in a database.