It makes sense comparing LG GX vs LG SL9YG because they both are able to give some premium features. Based on our rating, GX has a total rating of 6.5 out of 10 versus 8 for SL9YG. The competitors' control buttons are different: power, volume down, volume up, function 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 LG GX has 3.1 versus 4.1.2 for the LG SL9YG. The output power is different and equal to 420 (overall) W for the GX versus 500 (overall) W for the SL9YG. Competitors do not have a built-in subwoofer. Rivals have wireless connection to separate subwoofer. The LG GX got our rating of 7 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. 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 GX received a rating of 8/10 versus 7/10, respectively. App control is available in every soundbar. A built-in microphone is present only on the SL9YG. Multi-room is only available for the LG SL9YG.
Both devices have support for Dolby Atmos multichannel audio format. The surround sound technology DTS:X is supported by devices under review. For multichannel surround LG GX got a rating of 10, and LG SL9YG 8 out of 10.