LG SL9YG vs LG SLM4R comparison definitely makes sense. Based on our rating, SL9YG has a total rating of 8 out of 10 versus 5.2 for SLM4R. The competitors' control buttons are different: power, volume down, volume up, play/pause, microphone and power, volume down, volume up, function, respectively.
Both soundbars have active amplification type. A significant difference between the units in the number of channels, the LG SL9YG has 4.1.2 versus 4.1 for the LG SLM4R. The output power is different and equal to 500 (overall) W for the SL9YG versus 420 (overall) W for the SLM4R. Competitors do not have a built-in subwoofer. Rivals have wireless connection to separate subwoofer. The LG SL9YG got our rating of 8 out of 10, and the LG SLM4R 7 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 SL9YG received a rating of 7/10 versus 6/10, 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.
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 LG SL9YG got a rating of 8, and LG SLM4R 5 out of 10.