quality vs low quality

quality and low quality both are nouns.

Word	Noun	Adjective	Verb	Adverb
quality	Yes	Yes	No	No
low quality	Yes	No	No	No

As nouns, low quality is a hyponym of quality; that is, low quality is a word with a more specific, narrower meaning than quality:

Other hyponyms of quality include high quality, superiority, inferiority.

quality (noun)	low quality (noun)
an essential and distinguishing attribute of something or someone	an inferior quality
(music) the distinctive property of a complex sound (a voice or noise or musical sound)
a degree or grade of excellence or worth
a characteristic property that defines the apparent individual nature of something
high social status

quality (adjective)	low quality (adjective)
of superior grade
of high social status