A voice controlled assistant has a housing to hold one or more microphones, one or more speakers, and various computing components. The housing has an elongated cylindrical body extending along a center axis between a base end and a top end. The microphone(s) are mounted in the top end and the speaker(s) are mounted proximal to the base end. A control knob is rotatably mounted to the top end of the housing to rotate about the center axis. The control knob has an outer surface that is substantially flush with an outer surface of the housing to provide a smooth, continuous appearance to the voice controlled assistant.