Audio Input Adapter Subwoofer Receiver Subwoofer Adapter Upgrade Kit For Lo Z-5500 - Accessories - AliExpress
Logitech Z5500 Repair - Backlight Blinking, Not Booting up - YouTube
One of my Logitech Z5500's sub is making a vibrating noise with some bass frequencies. I already checked the inside and everything looks OK. I think is comes from one or both