speaker vs speaker unit

speaker and speaker unit both are nouns.

Word	Noun	Adjective	Verb	Adverb
speaker	Yes	No	No	No
speaker unit	Yes	No	No	No

As nouns, speaker and speaker unit are synonyms defined as:

speaker and speaker unit: electro-acoustic transducer that converts electrical signals into sounds loud enough to be heard at a distance

Other synonyms of speaker include loudspeaker, loudspeaker system, speaker system.

speaker (noun)	speaker unit (noun)
electro-acoustic transducer that converts electrical signals into sounds loud enough to be heard at a distance	electro-acoustic transducer that converts electrical signals into sounds loud enough to be heard at a distance
someone who expresses in language; someone who talks (especially someone who delivers a public speech or someone especially garrulous)