In a previous incarnation I did broadcast engineering and theatrical audio systems with frequency response from DC to light and spent a lot of time worrying about sound pressure levels +/- 1 dB from here to the bleachers.
Nowadays, in the shop - meh. A decent receiver from Goodwill, speakers that sound good to my upper frequency compromised ears (currently a pair of Cerwin Vegas) and I'm good to go. It's background music now to the sound of fans, motors, servos. and a cat yowling about waiting to be fed.
Nothing makes more difference than having speakers that sound good to you.
Tune into the Portland jazz station (KMHD-FM) and I'm good to go.
Stu