In 1898, Britain's Sir Oliver Lodge took the principle of the telephone loudspeaker one step further and invented the cone horn, which is very similar to the familiar modern horn. This invention determines the structure of 99% of modern moving coil loudspeakers, which Sir Oliver Lodge calls "the roaring telephone". But this invention could not be used, for the tripole vacuum tube was not invented until 1906 in Lee De Forest, and it would be several years before a usable amplifier could be made, so the cone horn did not become popular until the 1930s.
Twenty-five years later, in the 1920s, radio came along. C. W. Rice and E. W. Kellogg published their epoch-making paper "New Non-Number Carbon-type Unit", which detailed the direct radiant speaker. Using this theory, the Radiola 104 speaker was popular in the United States. The basic principles of electric loudspeakers have not changed over the past few decades, only improved design details and components. Frequency response range dynamic range and other aspects of the older products have been a considerable development. Electric loudspeaker with simple structure, excellent sound quality, low cost, large dynamic has become the current market mainstream.