"Good" sound is completely relative to your reference frame of your most accurate/hightest fidelity stereo listening experience.. this will change as soon as you hear something "better" (which should possess a higher fidelity to the recorded source than previous frame of reference)
I remember when I thought "Good Sound" was a Dual turntable with Ortofon cartridge, a Marantz receiver, and a pair of JBL L-100's. That frame of reference has of course changed many many times.
The Key, I believe, is to have experience hearing and remembering what real musical instruments played together in an unamplified listening space sound like... anything from a symphony hall to a church organ recital, solo classical guitar, live jazz at preservation hall, blues guitar player on the street, etc... match these experiences to what you hear coming out of the speakers.
I remember when I thought "Good Sound" was a Dual turntable with Ortofon cartridge, a Marantz receiver, and a pair of JBL L-100's. That frame of reference has of course changed many many times.
The Key, I believe, is to have experience hearing and remembering what real musical instruments played together in an unamplified listening space sound like... anything from a symphony hall to a church organ recital, solo classical guitar, live jazz at preservation hall, blues guitar player on the street, etc... match these experiences to what you hear coming out of the speakers.