Before revision: By the 1890s it was realized that damped waves had disadvantages; their energy was spread over a broad frequency band (signal processing)|bandwidth so transmitters on different frequencies interfered with each other, and they could not be modulated with an audio signal to transmit sound.
After revision: By the 1890s it was realized that damped waves had disadvantages; their energy was spread over a broad frequency band so transmitters on different frequencies interfered with each other, and they could not be modulated with an audio signal to transmit sound.