A speaker in which the radiating element acts directly on the air instead of relying on any other element, such as a horn.
"Thanks for the amazing restoration of the June, 1938 home recording on aluminum disc. A wedding gift, across continents, to my parents from my aunt and uncle singing beautifully to piano accompaniment with personal spoken words, is a treasure. I did not think it was possible since only wooden needles had to be used for playback. But you did it ..."