LG’s Modular Sound Bar Flex: The Gizmodo Review

LG’s Modular Sound Bar Flex: The Gizmodo Review

All photos: Adam Clark Estes

With the new Sound Bar Flex, LG didn’t make the world’s best sound bar. It’s actually a bit of a stretch to call the modular, three-piece speaker system a sound bar at all. And at $899, the (mostly) wireless setup isn’t quite a bargain either. You know what, though? The Sound Bar Flex sure is fun to use.

At CES in January, LG showed off an intriguing twist on the traditional TV sound bar that was nothing like the long bars of plastic produced by its competitors. The ambitiously named Sound Bar Flex (model number SJ7) is supposed to work as a portable speaker, a semi-surround sound system, and a traditional sound bar.

From a design perspective, the system works as an in-between. On one hand, it’s a very nice-looking and nice-sounding 2.1 surround system. On the other, it resembles a sound bar insofar as pushing the two speakers together creates the shape of sound bar: a long, thin line of speakers.

Yet, as companies strive to make their sound bars thinner and thinner so they slide underneath the TV and effectively disappear, the LG Sound Bar Flex is pretty husky. I tested the system with an HDMI Audio Return Channel (ARC) or optical audio cable. I’m getting a head of myself, though. Let’s talk more about how it actually works.

A small but easy-to-read display lets you control the equaliser, which doesn’t give you all that much control over the sound, unfortunately.

Functionally speaking, there are three pieces to the system: a stationary subwoofer as well as a primary speaker and a secondary speaker, both of which can become portable speakers using Bluetooth. The speakers connect to each other wirelessly, but you’ll need a cable to connect the primary sound bar speaker to your TV or audio receiver. The subwoofer, meanwhile, stays in one place and connects to the primary system via Bluetooth. It all sounds more confusing than it actually is. Setup is a breeze.

While anyone’s free to be creative with a modular system like this, there are three main ways to set up the LG system’s portable speakers. One: You lineup the two front speakers under your TV screen, like a sound bar. Two: You stand up or mount the front speakers along the sides of your TV for a more three-dimensional sound. Three: You set up the primary speaker underneath your screen and install the secondary speaker behind your couch. The choice is yours!

In rear mode, the primary speaker stays in front of the TV like a mini soundbar and the secondary speaker goes behind your couch.

This level of flexibility is really fun in small spaces. If you’re someone who likes the idea of switching back and forth between a theatre mode and a let-me-be-lazy mode, you’ll love LG’s approach. You really can use it as a regular sound bar, or, if you’d like something closer to a surround-sound experience, you can break it up and surround yourself with, umm, sound. For me, this is the difference between watching a baseball game, while enjoying a can of beer and watching an immersive sci-fi movie, while enjoying an iced-down glass of inexpensive rye. I’m not expecting an IMAX experience at any time in my tiny apartment. But sometimes, I do like to class it up, just a little.

In larger spaces, LG’s modular system ironically makes less sense. You’d think that having moveable speakers would be a boon to sprawling suburban living rooms, but actually, the LG system just isn’t all that loud. At 320 watts, the system is hardly the most powerful thing you could put in your living room. Cranking it up to max volume during a war movie like Hacksaw Ridge will feel immersive but not quite mind-blowing.

You can also stand up the sound bar speakers up, which makes the whole set up work more like a 2.1 channel surround system.

Going full wireless affects the speakers’ performance as well. When you disconnect the power supply from the portable sound bar speakers, the output power drops down to 140 watts so the rechargeable battery will last longer. However, less wattage means less volume. During the same explosion-filled scene of Hacksaw Ridge, the battery-powered speakers sounded about half as loud as they did when I had them plugged into a power supply.

When plugged in, the Sound Bar Flex audio quality is exceedingly decent in any size space. With the secondary speaker set up behind you, Hacksaw Ridge is indeed extra terrifying, since it sounds like the bullets are coming from all directions. In traditional sound bar mode, a roiling sci-fi like Rogue One sounds almost theatrical. The LG system did let me down when I tested it on Tron: Legacy, which is essentially a two-hour-long Daft Punk concert with visuals created by Disney. The audio sounded good, but I couldn’t quite make it blow my hair back.

Now about that wireless technology. The LG Sound Bar Flex is a wireless sound system, but it is not a wi-fi sound system. The speakers talk to each other using Bluetooth, a terrific technology that unfortunately requires pairing and connecting and putting up with some issues, like lag and interference. But if you want a top notch wi-fi sound system, you’re going to have pay more for it. For instance, you might consider the $999 Sonos Playbar, and if you really want to spend some coin, add a couple Sonos Play:1 speakers ($268 each) and a Sonos SUB ($999) for a true surround sound experience. All of those speakers have to stay plugged in to a power supply at all times, by the way.

Silly as it seems, I like to stuff the secondary speaker between the cushions and the wall, since I don’t have space to put a table back there.

While some people prefer wi-fi sound systems, a Bluetooth system like the Sound Bar Flex has its advantages. It’s cheaper than Sonos, and the LG system also offers more versatility since the speakers can run on battery power. Those rechargeable batteries only last four hours, mind you, but you might just want to rearrange them for one specific movie. My favourite trick was to plop the secondary speaker on the back of my couch for action movies, and switching up the arrangement literally takes me five seconds. Yet using the secondary LG speaker as a Bluetooth boom box — say, at the beach — makes less sense to me. It is decidedly not an outdoor speaker.

So do you see where I’m heading with this? The LG SJ7 is pricey, but it’s not even close to what you could spend to set yourself up with a slightly more sophisticated home audio system. The Vizio SB3851-DO Smartcast is a budget favourite. However, that system doesn’t offer the modularity of the LG setup.

With the subwoofer (left) and the two sound bar speakers (center), the whole system isn’t quite invisible, but it’s not too obtrusive either.

You can spend less money on a simpler sound bar that offers some surround sound features. You can also spend a lot more money on a full-featured system from LG’s high-end competitors. But this new system is essentially a really good compromise. The Sound Bar Flex sounds great — even though it’s not the loudest box on the block — you can rearrange the components quickly and easily, and the whole experience sure is a lot of fun, too.


  • The novel design lets you use LG’s speakers like a traditional sound bar or a 2.1 surround sound system or even a single portable Bluetooth speaker.
  • The speakers get pretty loud, but you’ll lose volume when you switch to the portable, battery-powered mode.
  • The system’s flexibility is fun, especially in smaller spaces where the surround sound effect works better and volume isn’t an issue.
  • $899 isn’t cheap for a sound bar, but really, the Sound Bar Flex is an entirely new kind of modular, wireless speaker system. Worth it.

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