Does the W7 work with non-LG soundbars?

No. It is designed to pair with LG Sound Suite soundbars and speakers over Wi-Fi and Dolby Atmos FlexConnect. A soundbar from another brand will not drive it.

LG rates the frequency response down to about 25.9 Hz, which covers the deep rumble in movie soundtracks and the low notes in most music.

Do I need a cable to the soundbar?

No. It connects wirelessly over Wi-Fi using FlexConnect, so you only need a power outlet near where you place it.

The cabinet measures about 410 x 415 x 194 mm and weighs 8.8 kg. Check floor space and clearance before placing it behind or beside a sofa.

Can I update its firmware?

Yes. The Upgrade Manager supports over-the-air updates, so fixes and improvements arrive without a USB stick.

Is one W7 enough for a large room?

It is a single 220 W driver. In a big or open room, expect it to fill the space at moderate levels rather than pressurize it like a larger multi-driver sub.