A sound output assembly includes an enclosure, a circuit board disposed in the enclosure, and including signal processing circuitry, and a speaker assembly. The speaker assembly includes a main body disposed inside the enclosure, and a supporting member configured to support the main body and having (i) a first portion fixed to the main body such that the first portion of the supporting member and the main body are formed as one body and (ii) a second portion fixed to the circuit board or to the enclosure. The main body includes an acoustic diaphragm in accordance with a signal supplied from the signal processing circuitry. The supporting member is configured to dampen vibration of the main body.