Vizio M-Series 5.1 Soundbar (M51a-H6) Review: Competent, Convenient, and Budget-Friendly

We’ve all been there, gazing longingly at the top-tier tech, even when a more affordable option would suffice. The Vizio M-Series 5.1 M51a-H6 soundbar falls squarely into that category. It’s a solid, dependable choice that delivers Dolby Atmos and DTS:X compatibility at a price that won’t make your wallet weep. However, it’s difficult to muster overwhelming excitement for it.

This soundbar is intentionally designed as an affordable, middle-ground alternative to the sleeker, higher-end models on the market. It’s challenging to get truly enthusiastic about "good" when "great" is within reach, albeit at a significantly higher cost. Another factor is that even pricey Dolby Atmos soundbar systems sometimes struggle to live up to their promises, let alone cheaper options. In many instances, soundbar-based home theater setups fall short when it comes to realistically simulating height. The result is a decent, but not perfect, effect. The M51a-H6, depending on your satellite speaker configuration, faces the same challenge. It’s not terrible, but it might leave you with a shrug and a feeling of "meh."

The words that best describe the M51a-H6 are competent and convenient. This 5.1 system includes a soundbar, a subwoofer, and two satellite speakers. The satellite speakers can be positioned on either side of the soundbar or behind you as rear speakers, providing some flexibility in setup. The soundbar itself has a low profile and a rather unassuming aesthetic, featuring a dark gray matte finish, a fabric grille, and physical controls on top. Vizio claims it houses nine individual speakers, with separate tweeters and woofers. Its dimensions of 36 x 2.2 x 3.5 inches (WHD) make it a good fit for TVs with shorter legs or smaller entertainment consoles. The satellite speakers resemble miniature soundbars, laying flat rather than standing upright. The 6-inch wireless subwoofer is also more compact than most I’ve tested, which could be advantageous depending on your available space. A remote control is also included, which is unremarkable. It does, however, provide a convenient method to cycle through specific pre-set sound profiles.

The M51a-H6’s rear panel features an HDMI input and output (eArc/Arc compatible), an optical input, a 3.5mm stereo mini-jack, and a USB port for updates. It also supports Bluetooth, allowing it to function as a speaker for your phone. You can also use it to enhance the sound of Google Assistant and Amazon Alexa devices that might have lackluster audio on their own. Unlike some other Vizio soundbars, the M51a-H6 lacks SmartCast, Vizio’s app for controlling home theater devices from your phone. Some users may find this disappointing, but I personally didn’t miss it, as I find the app somewhat unreliable.

Setting up the M51a-H6 was remarkably straightforward. Plug in the HDMI cables where they’re supposed to go, and you’re good to go. There are no complicated pairing procedures to worry about. Simply plug it into a power source and press the power button. The only decision that requires some thought is how to position the satellite speakers. In my setup, I was able to place them behind me, to the left and right, with the subwoofer off to the side of my couch, creating a "traditional" 5.1 configuration. However, if your space doesn’t allow for that, you can place all the speakers in a front-facing arrangement. Keep in mind that this isn’t ideal for true surround sound. The connecting cables for the satellite speakers are long enough and color-coded, but you might want to invest in some cable ties to avoid tripping hazards. You can also wall-mount the soundbar, but I didn’t attempt this myself, so I can’t comment on the ease of the process.

So far, the M51a-H6 is a pretty standard soundbar. There’s nothing flashy or gimmicky here, which is actually a relief when it comes to Dolby Atmos soundbar marketing. But convenience isn’t the only reason to buy a soundbar. Ultimately, you want an audio experience that’s significantly better than your TV’s built-in speakers.

For regular 5.1 surround sound, the M15a-H6 performs admirably. I watched Netflix’s "Umbrella Academy" and season 1 of Amazon’s "The Boys," and everything sounded great. Cars whizzed by in the appropriate directions, and explosions boomed—though they weren’t quite as impactful as on systems with larger subwoofers. I have a hard time hearing dialogue sometimes, but that wasn’t much of a problem here. And even at higher volumes, there was no noticeable distortion. I was surprised, then, by how the soundbar handled music.

The M15a-H6 had a relatively neutral sound profile with the Music EQ setting—not overly bass-heavy, and the mids weren’t too muddy. Again, it wasn’t as thumpy as some other soundbar systems I’ve tested, but that’s to be expected from a smaller subwoofer. The trouble began when I played Fleetwood Mac’s "Dreams" to evaluate the treble. The treble itself was fine! Stevie Nicks’ vocals were crisp, if a bit hollow. The problem was I heard a subtle popping noise. The volume wasn’t at max, so that was concerning. I switched to Olivia Rodrigo’s "Driver’s License," a song with more bass, and I heard faint pops there as well. To make sure I wasn’t imagining things, I asked my husband if he heard any popping, and he confirmed it. Oddly, the popping disappeared on Gershwin’s "Rhapsody in Blue," a song I use to test how soundbars handle dynamic shifts in volume. There was no crackling or distortion, but it also didn’t do the song justice. Overall, the M51a-H6 would be adequate for casual house parties, but I wouldn’t crank up the volume too much.

For Dolby Atmos content, I watched scenes from "The Mandalorian," "Star Wars: The Last Jedi," and "Star Wars: The Force Awakens" on Disney+ with the Movie EQ setting. The sound was pretty good, though there was a mildly tinny, hollow quality to it. I admit it’s not that noticeable unless you’ve heard a truly great soundbar and have others on hand for comparison. The Sony HT-G700 is another Dolby Atmos soundbar on the more affordable side, and it handled regular dialogue and music without that hollowness. However, unless you’re a serious audiophile, it’s unlikely to significantly detract from your viewing experience.

As for spatial sound, you get a good sense of depth and lateral space. You can clearly hear which direction spaceships are flying and where explosions are occurring. Again, explosions didn’t rumble as much as I would have liked, but it sounds better than single soundbar solutions like the Sonos Arc or the Panasonic SoundSlayer. During Kylo Ren and Rey’s Force Skype sessions in "The Last Jedi," it did a decent job of recreating the echo-y sound effect and indicating where each character’s voice was coming from. However, it wasn’t as crisp or well-executed as Vizio’s higher-end soundbar system, the Vizio Elevate.

The M51a-H6 struggled to simulate height. This isn’t a problem unique to this soundbar. Like the Sony HT-G700, this soundbar doesn’t have upward-firing speakers. The only reason I felt any degree of height is that the satellite speakers in my setup are positioned above ear level. However, I only heard spaceships flying overhead when they were swooping from the front to the rear. If the sound didn’t play on the rear speakers, I didn’t get a sense of anything happening above me. If you were to use a front-facing configuration, I doubt you’d get any sense of height at all.

The overall sound quality is fine—not amazing, but pretty good considering the soundbar’s suggested retail price of $350. (It’s currently listed at $250 on Vizio’s website, and you might be able to find it for even less at Costco.) And compared to the SoundSlayer, which retails for $300, this is a far better investment if you have the space.

Personally, I’m a cheapskate. I appreciated the Vizio Elevate’s rotating speakers and impressive sound, but I would have a hard time justifying spending that much money when my TV cost only $600. It seems a bit counterintuitive to skimp on your TV and then splurge on your home entertainment system. Compared to the $500 Roku 5.1 Surround Sound System and the $600 Sony HT-G700, the M51a-H6 holds its own, and for a couple hundred dollars less. You can’t add additional speakers if you ever want to expand your setup, but for under $350, it’s hard to argue with that kind of value.

To be honest, if I were creating a wishlist for someone else to buy me a 5.1 soundbar system with Dolby Atmos, this probably wouldn’t be my top choice. I’d probably opt for something more expensive with upward-firing speakers. However, if I were paying with my own money, I’d be perfectly content with this soundbar.

Pros:

• An inexpensive 5.1 Dolby Atmos-compatible system that doesn’t sound terrible.
• A simple, no-fuss system that’s easy to set up and should fit nicely in smaller spaces.
• Offers good sound quality for the price.

Cons:

• The Atmos experience isn’t the best, because there are no height channels.
• It’s not going to outperform higher-end speakers.

Verdict:

It’s hard to beat the price, and it can often be found at even lower prices at Costco and Sam’s Clubs.