It makes sense comparing VIZIO SB2821-D6 vs LG SL9YG because they both are able to give some premium features. Based on our rating, SB2821-D6 has a total rating of 4.8 out of 10 versus 8 for SL9YG. The competitors' control buttons are different: power, input, Bluetooth, volume down, volume up and power, volume down, volume up, play/pause, microphone, respectively.
Both soundbars have active amplification type. A significant difference between the units in the number of channels, the VIZIO SB2821-D6 has 2.1 versus 4.1.2 for the LG SL9YG. Competitors do not have a built-in subwoofer. Rivals have wireless connection to separate subwoofer. The VIZIO SB2821-D6 got our rating of 6 out of 10, and the LG SL9YG 8 for its audio features and specs.
Soundbars do not have AirPlay support. Spotify support is available on the SL9YG.
Only the LG SL9YG can connect to the Internet via WI-FI. Rivals from our review have Bluetooth support. Only the SL9YG supports HDMI Audio Return Channel (ARC). Both soundbars have a USB connector. For connectivity, the SB2821-D6 received a rating of 4/10 versus 7/10, respectively. App control is available for the SL9YG. A built-in microphone is present only on the SL9YG. Multi-room is only available for the LG SL9YG.
Only the SL9YG has a Dolby Atmos multichannel audio format support. A surround technology DTS:X is supported only by the SL9YG. For multichannel surround VIZIO SB2821-D6 got a rating of 5, and LG SL9YG 8 out of 10.