quadraphony vs quadriphonic system

quadraphony and quadriphonic system both are nouns.

Word	Noun	Adjective	Verb	Adverb
quadraphony	Yes	No	No	No
quadriphonic system	Yes	No	No	No

As nouns, quadraphony and quadriphonic system are synonyms defined as:

quadraphony and quadriphonic system: a stereophonic sound recording or reproducing system using four separate channels

Other synonyms of quadraphony include quadraphonic system.

quadraphony (noun)	quadriphonic system (noun)
a stereophonic sound recording or reproducing system using four separate channels	a stereophonic sound recording or reproducing system using four separate channels