While diapasons refers to a set of bells, organ pipes or musical instruments that produce a clear, harmonious sound, its antonyms are words that describe the opposite. Some antonyms for diapasons are discordant, disharmonious, cacophonous, unmelodious, and unharmonious. These words are used to describe sounds that are jarring, dissonant or harsh to the ear, and often associated with unpleasant, noisy or raucous environments. The opposite of diapasons refers to the lack of harmony, balance, and cohesion, and can be used to describe anything from music to speech, to relationships between people or things.