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
Logitech Z-5500 THX-Certified 5.1 Digital Surround Sound Spe $839.99 | Logitech, Surround sound speakers, Surround sound systems
Logitech Z-5500 THX-Certified 5.1 Digital Surround Sound Speaker System (970115-0403) - Newegg.com