I have an older Sony Reciever STR-SE545, technic 3 way 15" woofer front speakers, two smaller technic rears, and a technic center. I am having problems with static at low volumes. I have it hooked up using 18 guages wire and the reciever set to 8ohms to match the front speakers.
It its a old receiver it just may be worn. Rotary volume knobs wear to where they produce static as do old connectors. Best fix would most likely be a new receiver.
from what i’ve read this is the most likely problem long with a bad ground, I’m going to pull the reciever apart tomorrow, clean it and see if that fixes the static.