Intelligent amplifier activation

1. A first playback device comprising:

a network interface;

one or more processors; and

tangible, computer-readable media having instructions encoded therein, wherein the instructions, when executed by the one or more processors, cause the first playback device to perform a method comprising:

determining that a command associated with the first playback device is anticipated;

based on the determination that the command is anticipated, identifying one or more second playback devices of a zone group that is associated with the first playback device; and

after identifying the one or more second playback devices of the zone group and before receiving the command associated with the first playback device, causing, via the network interface, the one or more identified second playback devices of the zone group to activate respective amplifiers.

2. The first playback device of claim 1 , wherein determining that the command associated with the first playback device is anticipated comprises:

receiving, from a proximity sensor, data indicating movement relative to the first playback device.

3. The first playback device of claim 1 , wherein determining that the command associated with the first playback device is anticipated comprises:

identifying, in a database, data indicating that media content was previously rendered by the zone group at a time that corresponds to a current time indicated by a clock of the first playback device.

4. The first playback device of claim 1 , wherein a media playback system comprises the first playback device and the one or more second playback devices, and wherein identifying one or more second playback devices of the zone group that is associated with the first playback device comprises:

retrieving a state variable indicating a configuration of the media playback system; and

determining that the state variable identifies the one or more second playback devices as members of the zone group.

5. The first playback device of claim 1 , wherein causing the one or more second playback devices of the zone group to activate respective amplifiers comprises:

transmitting, to the one or more second playback devices of the zone group, respective messages that cause the one or more second playback devices to activate the respective amplifiers of the one or more second playback devices.

6. The first playback device of claim 1 , wherein causing the one or more second playback devices of the zone group to activate respective amplifiers comprises:

transmitting, to the one or more second playback devices of the zone group, respective messages that cause the one or more second playback devices to cache respective audio content.

7. The first playback device of claim 1 , wherein the method further comprises:

identifying a particular audio content based on the determination that the command associated with the first playback device is anticipated; and

pre-caching the particular audio content.

8. The first playback device of claim 1 , wherein receiving the command associated with the first playback device comprises:

after causing the one or more second playback devices in the zone group to activate a respective amplifier, receiving input data representing the command associated with the first playback device to play audio content, and wherein the method further comprises playing the audio content in synchrony with the one or more second playback devices in the zone group.

9. The first playback device of claim 1 , wherein the one or more second playback devices of the zone group are a subset of playback devices in a media playback system.

10. A tangible non-transitory computer-readable medium having stored thereon instructions executable by one or more processors to cause a first playback device to perform a method comprising:

determining that a command associated with the first playback device is anticipated;

based on the determination that that the command is anticipated, identifying one or more second playback devices of a zone group that is associated with the first playback device; and

after identifying the one or more second playback devices of the zone group and before receiving the command associated with the first playback device, causing, via a network interface, the one or more identified second playback devices of the zone group to activate respective amplifiers.

11. The tangible non-transitory computer-readable medium of claim 10 , wherein determining that the command associated with the first playback device is anticipated comprises:

receiving from a proximity sensor, data indicating movement relative to the first playback device.

12. The tangible non-transitory computer-readable medium of claim 10 , wherein determining that the command associated with the first playback device is anticipated comprises:

identifying, in a database, data indicating that media content was previously rendered by the zone group at a time that corresponds to a current time indicated by a clock of the first playback device.

13. The tangible non-transitory computer-readable medium of claim 10 , wherein a media playback system comprises the first playback device and the one or more second playback devices, and wherein identifying one or more second playback devices of the zone group that is associated with the first playback device comprises:

retrieving a state variable indicating a configuration of the media playback system; and

determining that the state variable identifies the one or more second playback devices as members of the zone group.

14. The tangible non-transitory computer-readable medium of claim 10 , wherein causing the one or more second playback devices of the zone group to activate respective amplifiers comprises:

transmitting, to the one or more second playback devices of the zone group, respective messages that cause the one or more second playback devices to activate the respective amplifiers of the one or more second playback devices.

15. A method comprising:

determining, via a first playback device, that a command associated with the first playback device is anticipated;

based on the determination that that the command is anticipated, identifying one or more second playback devices of a zone group that is associated with the first playback device; and

after identifying the one or more second playback devices of the zone group and before receiving the command associated with the first playback device, causing, via a network interface, the one or more second identified playback devices of the zone group to activate respective amplifiers.

16. The method of claim 15 , wherein causing the one or more second playback devices of the zone group to activate respective amplifiers comprises:

transmitting, to the one or more second playback devices of the zone group, respective messages that cause the one or more second playback devices to cache respective audio content.

17. The method of claim 15 , further comprising:

identifying a particular audio content based on the determination that the command associated with the first playback device is anticipated; and

pre-caching the particular audio content.

18. The method of claim 15 , further comprising:

after causing the one or more second playback devices of the zone group to activate respective amplifiers, receiving an input to play audio content; and

playing the audio content in synchrony with the one or more second playback devices of the zone group.

19. The method of claim 15 , wherein the one or more second playback devices of the zone group are a subset of playback devices in a media playback system.

20. The method of claim 15 , wherein a media playback system comprises the first playback device and the one or more second playback devices, and wherein identifying one or more second playback devices of the zone group that is associated with the first playback device comprises:

retrieving a state variable indicating a configuration of the media playback system; and

determining that the state variable identifies the one or more second playback devices as members of the zone group.