A network device, comprising: a microphone; a network interface; a processor, and a memory having stored thereon instructions executable by the processor, the network device configured for: while (i) a playback device (200, 604, 606) is playing a first audio signal in a playback environment, and (ii) the network device is moving from a first physical location to a second physical location within the playback environment, detecting, by the microphone, a second audio signal at different locations between the first physical location and the second physical location; based on data indicating the second audio signal and a pre-determined audio characteristic, identifying an audio processing algorithm to adjust an audio output of the playback device (202, 604, 606) when playing the first audio signal in the playback environment to produce a third audio signal having an audio characteristic substantially the same as the pre-determined audio characteristic, wherein the pre-determined audio characteristic is one of a particular equalization and a particular frequency response; and transmitting, to the playback device (200, 604, 606), data indicating the identified audio processing algorithm, wherein p(t)=z(t)/s(t) when: s(t) represents the second audio signal; z(t) is a predetermined audio signal representing the pre-determined audio characteristic; and p(t) represents the audio processing algorithm. a microphone; a network interface; a processor, and a memory having stored thereon instructions executable by the processor, the network device configured for: while (i) a playback device (200, 604, 606) is playing a first audio signal in a playback environment, and (ii) the network device is moving from a first physical location to a second physical location within the playback environment, (i) a playback device (200, 604, 606) is playing a first audio signal in a playback environment, and (ii) the network device is moving from a first physical location to a second physical location within the playback environment, detecting, by the microphone, a second audio signal at different locations between the first physical location and the second physical location; based on data indicating the second audio signal and a pre-determined audio characteristic, identifying an audio processing algorithm to adjust an audio output of the playback device (202, 604, 606) when playing the first audio signal in the playback environment to produce a third audio signal having an audio characteristic substantially the same as the pre-determined audio characteristic, wherein the pre-determined audio characteristic is one of a particular equalization and a particular frequency response; and transmitting, to the playback device (200, 604, 606), data indicating the identified audio processing algorithm, wherein p(t)=z(t)/s(t) when: s(t) represents the second audio signal; z(t) is a predetermined audio signal representing the pre-determined audio characteristic; and p(t) represents the audio processing algorithm. s(t) represents the second audio signal; z(t) is a predetermined audio signal representing the pre-determined audio characteristic; and p(t) represents the audio processing algorithm.