It makes sense comparing Vizio M21d-H8 vs LG S90QY because they both are able to give some premium features. Based on our rating, M21d-H8 has a total rating of 5 out of 10 versus 8 for S90QY.
Both soundbars have active amplification type. A significant difference between the units in the number of channels, the Vizio M21d-H8 has 2.1 versus 5.1.3 for the LG S90QY. Only the Vizio M21d-H8 has a built-in subwoofer. The Vizio M21d-H8 got our rating of 5 out of 10, and the LG S90QY 8 for its audio features and specs.
Spotify support is available on the S90QY.
Only the LG S90QY can connect to the Internet via WI-FI. Rivals from our review have Bluetooth support. Each soundbar has 1/1 HDMI inputs/outputs. The HDMI Audio Return Channel (ARC) feature supports both devices. Both soundbars have a USB connector. For connectivity, the M21d-H8 received a rating of 6/10 versus 8/10, respectively. Compared soundbars have no app control. A built-in microphone is present only on the M21d-H8. Soundbars do not have Multi-room support.
Only the S90QY has a Dolby Atmos multichannel audio format support. A surround technology DTS:X is supported only by the S90QY. For multichannel surround Vizio M21d-H8 got a rating of 5, and LG S90QY 10 out of 10.