Squeezebox Controller Audio Playback
From SqueezeboxWiki
Beginning with 7.3 firmware, the Squeezebox Controller (SBC) can be used for audio playback locally through the headphone jack or the controller's small internal speaker*.
This feature is considered beta quality. If problems are experienced while using this feature, help make it better by opening an issue in Bugzilla.
*editor's note: sound quality through the internal speaker is not great for music, but subjectively sufficient for e.g., talk radio. Think of it like a streaming pocket transistor radio :)
Enabling local playback
Local playback can be enabled through Settings->Advanced->Beta Features->Audio Playback
Selecting Controller as player
Select Choose Player
from the home menu on the controller, you may need to restart the controller before it appears. The controller should appear in the choose player menu:
Note: Plugging headphones into the controller's 3.5mm jack will automatically select the controller as your selected player