The story
From dub (“style of reggae music involving mixing of different audio tracks”) + plate (“music record, usually vinyl”).
Etymology from Wiktionary, CC BY-SA 4.0.
dubplate
dub·plateToday it means: An acetate or vinyl record pressed in very limited numbers, especially one issued to disc jockeys in advance of an official release; specifically (and originally), one containing a piece of dub music (a style of reggae music, often instrumental, involving the mixing of different audio tracks). Full definition →