30Hz to 30kHz is not standard, although it is good. It is also meaningless without qualifying it with +/- however many dB's.
You should do some reading because you clearly don't understand this or how it would relate to sound quality. But generally, a vague spec like you proposed is meaningless. It tells you nothing about the linearity and nothing about how many dB's the response is down at the frequency extremes...
You should do some reading because you clearly don't understand this or how it would relate to sound quality. But generally, a vague spec like you proposed is meaningless. It tells you nothing about the linearity and nothing about how many dB's the response is down at the frequency extremes...