Vizio M21D-H8 soundbar review: Huge sound, no subwoofer required

In my reviews, soundbars that include subwoofers often sound better than standalone soundbars with no subs, for one obvious reason: more bass. The subwoofer adds lots of low-end impact and creates a fuller sound, but those big bass boxes take up lots of room. What if you want a speaker that generates a big soundfield and good bass, but only uses the space in front of your TV? The Vizio M21D-H8 makes a great case for the single speaker system — it sounds huge yet remains relatively compact. 

The Vizio’s sound quality is a huge step above a television’s, which you’d expect, and set my toes tapping. It sounds good with most movies and music and is relatively easy to set up. Unlike almost any other single bar near this price the Vizio M21 includes two HDMI ports, which really boosts its flexibility. And there’s Bluetooth streaming your music as well.

At $150 the M21 is relatively affordable, although it doesn’t deliver the visceral bass of as subwoofer-equipped units around this price, such as the Creative Stage V2 or Vizio’s own V21. If you’re looking to ditch the subwoofer, however, there’s nothing in this price range that can challenge the Vizio M21 for compact size, excellent features and full sound. 

Going to a single bar

Soundbars aren’t typically known for their sleekness but I found the Vizio M21D-H8’s trapezoidal design quite striking. Call it a Toblerone if you like, I certainly do, but Vizio clearly doesn’t care. While it looks similar to the SB362An-F6 it replaces, the design has been simplified — the little triangles on one side are now replaced by a single Vizio logo, for example. On the other end are buttons for volume, source selection and Bluetooth.

This sound bar is 36 inches long and is designed to sit in front of your TV — provided you have enough clearance for its 2-inch height — or it can be mounted on the wall (with two keyhole ports) to point outward into your room. It includes six drivers comprising of two woofers, twin tweeters and a pair of 3-inch onboard “subwoofers.” There is no subwoofer output, however, so you can’t add a separate sub later.

The front of the cloth-covered cabinet includes a colored LED to denote the input as well as a series of white LEDs for volume. It’s a lot better than the old system, which was virtually incomprehensible, but still not as clear as an actual alphanumeric display, for example.

The rear has a scooped-out section for the inputs alongside two keyholes for wall-mounting. The biggest upgrade on the original, and perhaps the reason behind the $30 price bump, is the addition of two HDMI ports: HDMI in and HDMI ARC. While some people use their TVs as a switch, the additional HDMI is useful if, say, you use your smart TV for streaming and want to add a second device, like a gaming console. The soundbar also includes optical audio for hooking up your TV, two 3.5mm analog ports with one for a voice assistant like the Amazon Echo Dot, and a USB port for playing MP3s and WAVs from a thumb drive. 

The Vizio has both Dolby and DTS decoding, which is impressive for a sound bar at any price, plus it has DTS Virtual:X, which is designed to simulate sound coming from around and above you, and that works especially well.

The remote offers powerful levels of control for a cheap soundbar, with volume plus two bands of EQ and an input selector. The back of the remote helpfully includes a color code chart of the inputs.

How does it sound?

The M21’s audio quality was very good overall, although is lack of bass compared to subwoofer-equipped units came through in my comparisons. 

As I’ve found with previous soundbars featuring DTS Virtual:X, this technology really helps fill a room with lifelike sound. Head to head against a soundbar that doesn’t have it, like the Creative Stage V2, the differences are obvious. The Vizio was easy to lose physically while watching blockbuster movies, while the Creative’s sound always seemed like it was coming from the cabinet.

The Vizio’s expansive soundstage was immediately obvious during the lobby scene in The Matrix. After Neo (Keanu Reeves) trips the metal detector and decorates the marble-walled room with garlands of lead, a single soldier shouts “Freeze” (1.42:09)  The shout and its slow decay filled the room in a way the Creative couldn’t. Yet the Creative was able to articulate the explosions and bass-led soundtrack that the subwoofer-less Vizio missed.

Compared against the Vizio V21, another unit with a subwoofer, the M21’s openness and relative lack of bass were once again apparent. The M21 sounded more vibrant during the lobby scene, even if it couldn’t match the V21 for impact. That deep bassline popped up now and again on the single bar when there wasn’t anything else happening, but I heard it full throttle with the V21. 

One thing you don’t often get from a budget soundbar, even one with Bluetooth, is affinity with music, yet the Vizio held its own with a number of different genres. It was able to present vocals with convincing articulation, and make the instrumentation coalesce as one unit. 

With the chill anthem Lebanese Blonde by Thievery Corporation, for example, the Vizio sounded smooth through the bass and midrange even if it lacked the oomph other soundbars get with a separate sub. On the Creative Stage V2 music was tight and a bit more thrilling, although it demonstrated one of the potential weaknesses of these kind of systems — the lower mids seemed to be missing. As a result the song came across as a little thin sounding.

Should you buy it?

The Vizio M21 is an excellent single-bar system with plenty of connectivity and a sophisticated, subtle design. I know of no other single bar that costs less than $200 that offers as much. 

That said, it’s cannibalized by the existence of the company’s own M21: at $150 the V21 is comparatively too much. While it’s regularly on sale for $120, and is $116.22 at Amazon right now, a lot of places sell it for full price. For the same $150 you can buy the V21, and it comes with a wireless subwoofer, so if it’s a choice between the two get the V21 instead. Similarly the $109 Creative Stage V2 offers a separate sub which also lifts its performance, and bargain hunters looking to extract the maximize performance for the littlest amount of money should get (the) Creative.