LG SL8YG soundbar review: Generally excellent sound quality, though only in certain circumstances

LG’s SL8YG soundbar fulfills the goal of delivering better sound than what your TV’s puny audio system puts out, and it goes one step further, offering Dolby Atmos and DTS:X immersive sound from a single speaker and a wireless subwoofer. Once it’s set up properly—and you’re sitting in the right spot—it sounds really good. It has other limitations, however, that are surprising at its price point.

Features

The LG SL8YG soundbar measures 41.7 x 2.2 x 4.7 inches (WxHxD) and weighs in at a hefty 9.7 pounds. You can mount it on the wall with the included mounting brackets or simply place it on the stand in front of the TV. The sub is relatively compact at 8.7 x 15.4 x 12.3 inches (WxHxD) with a weight of 17.2 pounds. The sub connects to the soundbar wirelessly using a dedicated 5GHz protocol, so it can be easily placed anywhere in the room. Of course, both units must be plugged into an AC power outlet.

As I mentioned at the outset, the SL8YG offers Dolby Atmos and DTS:X immersive audio, which reproduces sounds coming from various directions, including overhead. Atmos and DTS:X can utilize many configurations of speakers around and above the listener; in this case, there are three front channels and two overhead channels. Including the subwoofer, this is known as a 3.1.2 configuration (three front channels, one subwoofer channel, two overhead channels). The overhead channels rely on speaker drivers aimed at the ceiling, which reflects the sound back down to the listener. Of course, the ceiling must be flat and reflective for this to be effective.

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A total of eight drivers are housed in the sealed soundbar enclosure. Each of the three front channels are reproduced by a 0.8-inch silk-dome tweeter and a 1.6 x 3.9-inch woofer, while two 2.5-inch, upward-facing drivers reproduce the overhead channels. The front left and right drivers are powered by 50 watts each, while the center and overhead drivers get 40W each. My only quibble here is that the center channel should get at least as much power as the front left and right, since it reproduces most of the dialog, making it the most important channel of all.

The ported subwoofer cabinet houses a 7-inch driver powered by a 220W amp. According to LG, its frequency response extends from 35Hz to 160Hz, where the soundbar takes over and reproduces frequencies all the way up to 40kHz (±3dB).

You can add a pair of optional surround speakers to create a 5.1.2 system. The SPK8-S package ($179.99) comes with two surround speakers and a wireless receiver that connects to the speakers with wires, so the receiver needs to be placed near the speakers. These are included in the photo up top, although they were not a part of this review. I wish these surround speakers had upfiring drivers as well to form a 5.1.4 system; I strongly prefer four overhead channels rather than two such channels.

High-resolution audio is all the rage these days, and the SL8YG supports up to 96kHz/24-bit digital audio. It can also upsample lower resolutions to 24 bits. LG partnered with British high-end audio company Meridian to develop advanced signal processing and refine the hardware design to take maximum advantage of high-res audio.

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Supported lossless audio formats include PCM, Dolby TrueHD, DTS-HD Master Audio, WAV, and FLAC. In addition, the SL8YG supports all the main lossy formats, including Dolby Digital and Dolby Digital Plus, DTS, DTS-HD High Resolution, MP3, AAC, and AAC+.

The SL8YG offers several sound modes, including Standard, Movie, Music, Bass Blast, and ASC (Adaptive Sound Control). According to the manual, ASC “analyzes the property of the input sound and provides the sound optimized for the content in real time.” The Standard mode utilizes Meridian technology, while the Movie and Music modes are said to optimize the sound for those types of content. The purpose of Bass Blast is obvious.

In addition, you can adjust the level of the subwoofer, center channel, overhead channels, and rear channels (if you have the optional wireless surround speakers connected). Treble and bass EQ controls are also available.

The SL8YG offers a surround function that upmixes all input signals to 3.1.2 (or 5.1.2 if you have the optional surround speakers), regardless of their native channel configuration. This function was developed by Meridian. If you turn it off, input signals are reproduced as close to their original channel layout as possible, but only in certain sound modes (ASC, Standard, and Music). In the Movie and Bass Blast modes, everything is upmixed to 3.1.2 or 5.1.2, even with the surround function disabled.

Connections include one HDMI 2.0 input and one HDMI 2.0 output with ARC (Audio Return Channel). This lets you connect the HDMI output from a source device to the soundbar’s HDMI input and its HDMI output to the TV’s HDMI input. If the TV supports ARC, it will send its internal audio—say, from its internal over-the-air tuner or streaming apps—along the same HDMI cable back to the soundbar.

LG says the HDMI connections can pass 4K video signals from the source through the soundbar and on to the display. According to the company, those connections operate at a bandwidth of 13.5 Gbps, not the maximum of 18 Gbps, in order to ensure compatibility with existing TVs.

LG

I’m disappointed that the SL8YG has only one HDMI input. This is quite limiting if you have more than one source device. It turns out, however, that few soundbars have multiple HDMI inputs, and that most users connect multiple HDMI source devices to the TV and use it to switch sources.

I don’t like that approach. You could connect the optical digital-audio output from the TV to the soundbar, but the optical output on some TVs only sends 2-channel audio, not 5.1 or anything else. Even if your TV can send 5.1 audio from its optical output, it can’t send Dolby Atmos that way; no TosLink connection has enough bandwidth for that.

Alternatively,  you could connect the TV’s HDMI ARC input (if it has one) to the HDMI ARC output on the soundbar. This configuration will send bitstream audio—possibly including Atmos encoded in Dolby Digital Plus, but not Dolby TrueHD—from the selected HDMI input on the TV (or audio from the TV’s tuner or streaming apps) to the soundbar. Not all TVs support Atmos via ARC, however, especially since conventional ARC has a maximum bitrate of only 1Mbps. The next-generation eARC (enhanced Audio Return Channel) has a max bitrate of 37Mbps, so it can easily convey Atmos even in lossless Dolby TrueHD. But TVs with eARC are rare at this point. Also, using ARC to send audio to the soundbar occupies one HDMI input on the TV that could otherwise be used for another source device. 

A much better solution would be to have multiple HDMI inputs on the soundbar and use it as the source switcher. In most cases, the soundbar is performing a function similar to that of an AV receiver, which provides all HDMI switching in an AVR-based system. This is especially important for Dolby Atmos-enabled soundbars like the SL8YG to make sure they can receive an Atmos bitstream from multiple Atmos-capable source devices. I have no idea why more manufacturers don’t do this in their high-end soundbars.

Other physical connections include a TosLink optical input and a USB port, which can play audio files from a USB storage device in MP3, AAC, and OGG formats. Then there are the available wireless connections—Wi-Fi and Bluetooth 5.0 using the SBC codec and A2DP profile. Wi-Fi facilitates a couple of useful features, including Chromecast, which lets you cast content from a compatible phone’s streaming apps as well as group other compatible speakers into a whole-home audio system. The SL8YG also offers Google Assistant voice control.

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User Interface

There are several touch-sensitive “buttons” on the top of the SL8YG; in fact, they are nothing more than touch-sensitive labels with no physical buttons at all. They include power on/off, F (Function, which cycles through the inputs), volume down, volume up, play/pause, microphone mute, and Google Assistant. Two small holes just below these controls house the microphones for voice commands. Labeling the input-selection button “F” rather than “Input” or “Source” makes no sense to me.

A four-character alphanumeric display is located behind the grille on the front. Four dots below the display indicate the volume level when you change it; otherwise, they indicate that Google Assistant is ready to respond to your commands—or not if the microphones are muted. The display dims after 15 seconds of inactivity, but it can’t be turned off completely.

The included remote is small and a bit confusing. It includes a power button and a volume up/down rocker along with another rocker with “F” (input selection) on top and speaker-mute below it. Below them are a Sound Effect button that selects the sound mode, the Google Assistant button, and the microphone-mute button.

Also on the remote are play/pause, skip-forward, and skip-back buttons for music playback as well as a button that accesses the level and EQ controls and one that engages night mode, which reduces the dynamic range to allow low-level listening without disturbing others. Two buttons labeled Folder Up and Down let you navigate folders of audio files on a USB device, and a repeat button selects the repeat or random mode for music playback. Finally, the Info button displays information about the selected input source, such as the Bluetooth device name, audio format coming into the optical or HDMI input, and file information on a USB device.

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Overall, I’m unimpressed with the user interface. Aside from labeling the input-selection button F, some of the information displayed on the front panel is fairly cryptic because it has so few characters. And I really wish that the display could be turned off completely; even dimmed, it’s visually distracting right below the TV screen.

On the plus side, it’s easy to set the SL8YG to respond to volume and mute commands from the TV or source-device remote. Simply hold the Sound Effect button for three seconds to turn this function on, and the soundbar will respond to the commands from many different brands of remote. It worked perfectly with the remote for my Dish receiver, which is programmed for Sony TV volume and mute commands.

Performance

I installed the SL8YG below my Sony KDL-40V5100 HDTV in the bedroom, which has an 8-foot 3-inch flat, reflective ceiling. For my formal testing, I used an Oppo UDP-103 Blu-ray player set to bitstream output, which is what the soundbar needs for Dolby Atmos. I connected the player’s HDMI output to the soundbar’s HDMI input and the soundbar’s output to the TV’s input using HDMI cables from Metra Home Theater.

Starting with a Dolby Atmos demo disc, I played the 5.1.2 test tones, which consist of wideband noise in each channel sequentially. The front left, center, and right tones emanated from the correct locations within the soundbar, while the surround channels came from the front as well, though at a lower level.

The overhead channels seemed to come from overhead only when I was within four to five feet from the soundbar; moving back to a distance of 10 feet caused these channels to come from the front, not overhead. Even when I was five feet away, some of the sound seemed to come from the soundbar, indicating that those drivers are not as acoustically isolated as they should be. Also, I suspect that the drivers point straight up rather than at a slight angle forward as Dolby specifies. If they were angled, the overhead effect would extend farther back into the room. Even after repeated requests for confirmation, LG did not verify this.

LG

I played several other items on the Dolby Atmos demo disc, including the Amaze trailer, which includes rain and thunder. At a distance of five feet, it sounded nicely immersive with rain and other sound effects overhead, though the soundstage did not extend much beyond the soundbar enclosure to the left and right. The overhead effect was not as pronounced at 10 feet, but it was still evident.

Listening to the Audiosphere demo at five feet, the immersive soundstage was quite good, though the imaging in front was not as precise as it should be with this particular clip. The Leaf and Shattered trailers both exhibited an excellent immersive soundstage, which extended a bit beyond the enclosure, but not very much. The overhead effect in both cases was very good at that distance, and some of it remained at a distance of 10 feet.

Next, I listened to a couple of the audio-only demos on that disc. The helicopter demo is—what else?—the sound of a helicopter circling overhead. Without the optional surround speakers, the sound simply moved back and forth across the front soundstage, though it certainly did sound like it was overhead at a seating distance of five feet. The overhead effect was greatly diminished at a distance of 10 feet, but it was still there slightly. The same was true of the rainstorm audio demo.

Among the music-video selections on the Dolby Atmos demo disc is “Bailando” by Enrique Inglesias, which is one of my favorite Atmos music mixes. At a distance of five feet, the soundstage was smooth and very immersive with plenty of overhead activity and some extension beyond the left and right boundaries of the enclosure. At 10 feet, the immersive soundstage survived a bit better than the previous examples I tried.

Finally, I watched a clip from Gravity on Blu-ray, which has one of the best Atmos soundtracks I’ve heard. In particular, the scene with Ryan Stone (Sandra Bullock) in the International Space Station has sounds all around, especially when a fire breaks out, and the immersive soundstage from the SL8YG was excellent at five feet. It was still pretty good at 10 feet, though it was more forward, as expected.

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Throughout my Atmos listening, the SL8YG’s overall sound was nice and rich while remaining fairly clean and open. The subwoofer produced clean, balanced bass, though it was not prodigious. When the soundbar receives an Atmos bitstream, the various sound modes are disabled.

In addition to Blu-rays, I watch TV from a Dish satellite receiver—which meant swapping HDMI cables from the player to the satellite receiver. In this case, I tried the sound modes, and I had a strong preference for the Movie mode, which exhibited much better dialog balance than any of the other modes. It was also much louder and sounded richer and fuller than the other modes. By comparison, the Music mode sounded very closed in, and Standard seemed quite reserved and veiled. ASC was fairly clean, while Bass Blast was obviously over-enhanced.

I also listened to some music via Bluetooth. I still preferred the Movie mode in this case. Music mode sounded very closed in—yuck! ASC was thin and bright, while Bass Blast was very bright and shiny with lots of boom. In Standard mode, the sound was somewhat veiled and thin—surprising, since this is the mode that Meridian worked on.

Bottom Line

I really enjoyed the sound quality of the LG SL8YG in certain circumstances. With Dolby Atmos—and sitting within five feet of the soundbar—I heard a very good immersive soundfield with rich, clean sound. But moving back to a more normal seating distance of 10 feet, much of the overhead effect disappeared. Other content sounded quite good in Movie mode, but none of the other modes sounded good at all.

Equally disappointing is the inclusion of only one HDMI input. At nearly $800, it should have at least two. As I discussed earlier, not many soundbars provide more than one HDMI input, but there are a few that do. For example, the Sony HT-Z9F is a 3.1.2 soundbar with two HDMI inputs for $700, the Nakamichi Shockwafe Pro 7.1 SSE is a 7.1.4 (!) soundbar with rear speakers and three HDMI inputs for $900, and the Pioneer FS-EB70 is a 3.1.2 soundbar with four HDMI inputs for $1,000. With the SL8YG, you’ll need to use the TV as the HDMI switcher, which has a few potential disadvantages, or get a separate HDMI switcher, which complicates the use of the system.

On the plus side, you can feed it music via Bluetooth and Wi-Fi with Chromecast built in as well as from a USB storage device, and it upmixes non-immersive content nicely. I like that level of flexibility, but it’s not enough to make up for only one HDMI input and limited seating options to fully experience immersive audio.

This article was updated after publication to expand its discussion of the benefits of having multiple HDMI inputs on a soundbar.