Your TT looks to be pretty well isolated using the SRA platform. You rack looks OK too.
All-the-same, like Rodman99999, I believe that you have acoustic feedback when you play LPs. It could very well be the speaker design. It could also be a subsonic resonance w/ your tonearm.
If you can get your hands on the HiFi News & Record test LP you might be able to test @ what freq your tonearm-cartridge is resonant. Confirm that it is indeed resonant @ the freq you expect it to be.
All-the-same, like Rodman99999, I believe that you have acoustic feedback when you play LPs. It could very well be the speaker design. It could also be a subsonic resonance w/ your tonearm.
If you can get your hands on the HiFi News & Record test LP you might be able to test @ what freq your tonearm-cartridge is resonant. Confirm that it is indeed resonant @ the freq you expect it to be.