A speaker, a television provided with the speaker and a multimedia device are provided. The speaker includes a box body and a plurality of transducer units installed within the box body by means of parallel connection: front sound cavities of the plurality of transducer units are independent of each other, respectively; and the plurality of transducer units share one back sound cavity. The speaker possesses such advantages that it has a high sound pressure level output and a smaller power consumption, it is usable to reduce the back-cavity acoustic resistance, and it is usable to raise the lower frequency limit in the low frequency range.