Logitech Z3e vs Logitech Z4 2.1 system sound & bass test - YouTube
Logitech Z4 Computer Speakers for sale online | eBay
Logitech Z4 vs. Bose Soundtouch 20? I could get a Bose for 250 € to replace my Z4+LG Smartphone setup. You think it's worth it soundwise? : r/Soundbars
Original Logitech Z4 Speaker Volume Bass Controller Control Pod ONLY PID R817 | eBay