A broadcasting system configured to transmit signals to speakers, the broadcasting system comprising: a single loop configured by multiple signal lines, to which at least one of the speakers is configured to be connected; one or more isolators arranged between the signal lines configuring the loop; and a broadcast output device configured to transmit an output signal to the loop, wherein the broadcast output device is configured to superimpose an input signal on a direct current voltage to generate the output signal, which is transmitted to the loop, each of the isolators is actuated based on the output signal to detect a short circuit of the signal lines connected to the isolator, when the short circuit is not formed, each of the isolators connects the signal lines connected to the isolator to each other, and when the short circuit is formed, each of the isolators disconnects the signal lines connected to the isolator from each other, characterized in that each of the isolators includes a third terminal and a fourth terminal, a separation switch arranged on an internal signal line (21, 41, 51) that connects the third terminal to the fourth terminal, a third short circuit detector that detects a short circuit in a portion located toward the third terminal from the separation switch, and a fourth short circuit detector that detects a short circuit in a portion located toward the fourth terminal from the separation switch, and the separation switch disconnects the third terminal from the fourth terminal when at least one of the third short circuit detector or the fourth short circuit detector detects a short circuit, and connects the third terminal to the fourth terminal when none of the third short circuit detector and the fourth short circuit detector detects a short circuit, each of the isolators includes a power supply voltage generation circuit that generates a power supply voltage based on an output signal transmitted through the signal lines and supplies the power supply voltage to the third short circuit detector and the fourth short circuit detector, the power supply voltage generation circuit includes two input portions (49a, 49b) and the power supply voltage is generated regardless of a direction in which the output signal is transmitted. a single loop configured by multiple signal lines, to which at least one of the speakers is configured to be connected; one or more isolators arranged between the signal lines configuring the loop; and a broadcast output device configured to transmit an output signal to the loop, wherein the broadcast output device is configured to superimpose an input signal on a direct current voltage to generate the output signal, which is transmitted to the loop, each of the isolators is actuated based on the output signal to detect a short circuit of the signal lines connected to the isolator, when the short circuit is not formed, each of the isolators connects the signal lines connected to the isolator to each other, and when the short circuit is formed, each of the isolators disconnects the signal lines connected to the isolator from each other, characterized in that each of the isolators includes a third terminal and a fourth terminal, a separation switch arranged on an internal signal line (21, 41, 51) that connects the third terminal to the fourth terminal, a third short circuit detector that detects a short circuit in a portion located toward the third terminal from the separation switch, and a fourth short circuit detector that detects a short circuit in a portion located toward the fourth terminal from the separation switch, and the separation switch disconnects the third terminal from the fourth terminal when at least one of the third short circuit detector or the fourth short circuit detector detects a short circuit, and connects the third terminal to the fourth terminal when none of the third short circuit detector and the fourth short circuit detector detects a short circuit,