A display apparatus, control method, and system are provided. The display apparatus includes a display; one or more loudspeakers; a signal processor configured to process an image signal so that an image may be displayed on the display and sound may be output from the loudspeaker; a communication interface configured to communicate with one or more external display apparatuses; and a controller configured to transmit sound processed by the signal processor to the one or more loudspeakers in accordance with a preset output designation state, determine a divided and displayed state of an image with respect to the display apparatus and the one or more external display apparatuses, and adjust the output designation state of the sound with respect to the one or more loudspeakers based on the determination.