quadraphony vs stereophony

quadraphony and stereophony both are nouns.

Word	Noun	Adjective	Verb	Adverb
quadraphony	Yes	No	No	No
stereophony	Yes	No	No	No

As nouns, stereophony is a hypernym of quadraphony; that is, stereophony is a word with a broader meaning than quadraphony:

quadraphony: a stereophonic sound recording or reproducing system using four separate channels
stereophony: reproducer in which two microphones feed two or more loudspeakers to give a three-dimensional effect to the sound

Other hypernyms of quadraphony include stereo, stereo system, stereophonic system.

quadraphony (noun)	stereophony (noun)
a stereophonic sound recording or reproducing system using four separate channels	reproducer in which two microphones feed two or more loudspeakers to give a three-dimensional effect to the sound