Paul, two possibilities. If your sub has room control turn it off and see if the problem goes away. Then as others have mentioned, feedback which can be worsened further with room control. The feed back can be due to a cartridge tonearm mismatch but can also be due to improper turntable isolation. An SME , SOTA or Basis turntable will never do this.
Subwoofer rumble issue
I’m having a hard time solving a problem that seems to come and go. My subwoofer will rumble uncontrollably when playing records at a higher volume. If I turn the volume down sharply it goes away but when I creep the volume back up it comes back. I’ve tried isolating my turntable as much as possible with diy books, isolation feet, etc. (I don’t want to buy an expensive isolation platform unless that really is the issue.) Any thoughts on what I can do to fix this? Thx!