I’m having the same problem. I have a Technics 1200 M3D and KEF LS50s. No issues. I just added a REL T7i and have the runaway feedback rumble at high volume. I added Isonoe footers to the table which didn’t do much. Unfortunately the table and speakers sit on a big media cabinet from Design Within Reach which is not ideal. Not sure what the right next move is. More table isolation, put footers under the cabinet legs, new turntable, new furniture, or new house?
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!