i recently noticed a rather concerning issue with the subwoofer. I turned on my TV one day and somehow the subwoofer sounded very pale. Then i played a frequency response video (there are plenty on youtube) to see whether everything is in order and i noticed that between 50-30hz i hear residual sound (It is not very strong but certainly noticeable). Can anyone try the same and let me know whether you hear anything in those frequencies? I test at volume 18 with bass increased to +4. It can be also due to new firmware or just my ears are playing with me. I never did such test before, hence do not really have a benchmark.
I have an issue with my subwoofer. During Dolby Atmos or DTS-X movies, during heavy bass scenes my subwoofer emits a buzzing/blown out sound from it's port hole on the rear. It's been this way from new but has worsened recently so I sent it away for repair or replacement while still in warranty.
During 4k blu-ray movies like Lord of the Rings trilogy or Deepwater Horizon it was really distracting.