Vizio M Series M51a-H6 Soundbar Review

Tested using Methodology v1.0
Reviewed Mar 11, 2021 at 08:33 am
Vizio M Series M51a-H6 Picture
8.2
Mixed Usage
8.6
Dialogue/TV Shows
8.0
Music
8.1
Movies
This soundbar was replaced by the Vizio M Series M51ax-J6
Channels
5.1

The Vizio M Series M51a-H6 is a 5.1 setup from 2020. It's currently available from Costco and the manufacturer's website. This soundbar has a really neutral, balanced sound profile out-of-the-box, and its dedicated subwoofer helps to add a little extra kick in the bass range. There are even a few EQ presets to help you customize its sound to your liking. It also offers a great surround performance thanks to its dedicated satellites. While it supports Dolby Atmos content, its performance isn't the most impressive.

Our Verdict

8.2 Mixed Usage

The Vizio M51a-H6 is impressive for mixed usage. Out-of-the-box, it has a very neutral sound profile that's suitable for listening to lots of different types of audio content. Its dedicated subwoofer adds a little extra kick in the bass range that's ideal for watching action-packed movies or listening to bass-heavy music. It comes with dedicated surround speakers, and while it supports Atmos content, it doesn't provide the most immersive listening experience.

Pros
  • Supports Atmos content.
  • Gets loud.
  • EQ presets.
Cons
  • Middling height performance.
  • No graphic EQ.
8.6 Dialogue/TV Shows

The Vizio M51a-H6 is impressive for dialogue-centric content like TV shows. Thanks to its dedicated center channel and balanced mid-range, voices are reproduced clearly and accurately. There's even a dialogue enhancement feature to make voices sound more crisp, and it gets pretty loud, too. You can also wirelessly stream podcasts from your phone to the bar via Bluetooth, but unfortunately, it doesn't support Wi-Fi.

Pros
  • Gets loud.
  • Dialogue enhancement feature.
  • EQ presets.
Cons
  • Only supports Bluetooth wireless.
8.0 Music

The Vizio M51a-H6 is great for music. Its neutral sound profile is suitable for listening to lots of different genres, and there's even a little extra kick in the bass that can please fans of bass-heavy music like EDM. There are a few EQ presets as well as bass and treble adjustments to help you customize its sound, too. Unfortunately, it lacks a more comprehensive graphic EQ.

Pros
  • Gets loud.
  • EQ presets.
Cons
  • No graphic EQ.
8.1 Movies

The Vizio M51a-H6 is great for movies. It has a balanced, neutral sound profile with a little extra kick in the bass that's ideal for watching action-packed scenes. It comes with dedicated surround speakers, and it gets pretty loud, which is handy. While it can play Atmos content thanks to its front-firing speakers, unfortunately, it doesn't have a very impressive performance.

Pros
  • Supports Atmos content.
  • Gets loud.
  • Dialogue enhancement feature.
Cons
  • Middling height performance.
  • 8.2 Mixed Usage
  • 8.6 Dialogue/TV Shows
  • 8.0 Music
  • 8.1 Movies
  1. Updated Mar 11, 2021: Review published.
  2. Updated Mar 08, 2021: Early access published.

Test Results

perceptual testing image
Market Context
Market Context
Market Context

The Vizio M51a-H6 is a 5.1 soundbar from the company's 2020 lineup. It's part of Vizio's M-Series lineup, and unlike the 2.1 Vizio M-Series M21d-H8R, it comes with a dedicated subwoofer and two satellites. It's also more affordable than the Vizio Elevate, which was also released in 2020 and comes with up-firing speakers. Its main competitors include the Vizio V Series V51-H6, the Vizio SB36512-F6, and the Yamaha ATS-2090.

Design
Design
Style - Bar

The Vizio M51a-H6 is a simple, all-black soundbar. It's mostly made of plastic with a thin fabric covering the front and the sides.

Design
Style - Subwoofer

The sub sits on four plastic pegs that have rubber grips. It's mostly made of plastic. The port is located on the back of the sub, and the speaker is located underneath.

Design
Style - Satellites

This soundbar comes with two satellite speakers that have a similar design to the bar. They're mostly made of plastic with fabric covering the front and the sides.

Design
Dimensions - Bar
Width 36.0" (91.5 cm)
Height 2.3" (5.8 cm)
Depth 3.5" (9.0 cm)

The Vizio M51a-H6 isn't very wide, but it likely won't fit between the legs of a 55" TV. However, it isn't very tall, so it shouldn't block your TV screen unless your TV sits flush on the table.

Design
Dimensions - Subwoofer
Width 8.3" (21.2 cm)
Height 9.9" (25.2 cm)
Depth 11.7" (29.7 cm)

The subwoofer is roughly the same size as the subwoofer for the Vizio V Series V51-H6, though it's deeper. It's a bit shorter than the average desktop PC.

Design
Dimensions - Satellites
Width 5.7" (14.6 cm)
Height 2.3" (5.8 cm)
Depth 3.5" (9.0 cm)

The satellites are fairly small. They don't need a power cable to operate, but you need to wire them to the subwoofer to get them to work.

Design
Back - Bar
Bar Mounting
Universal (holes on underside)

On the back of the bar, there are two openings for the inputs and the power cable. There are also universal holes underneath it so you can wall-mount the bar.

Design
Back - Subwoofer
Enclosure
Ported

On the back of the subwoofer, there's an input for the power cable, as well as two jacks for the satellite speakers. There's also the port.

Design
Back - Satellites
Mounting
Proprietary

The satellites have a plain back with connections for the cable that connects them to the subwoofer. You can mount them to the wall using the included wall-mount screw and bracket, but you have to purchase the bracket screw separately.

7.0
Design
Build Quality

The Vizio M51a-H6 has a decent build quality. The bar and the satellites are mostly made of matte plastic, which feels quite solid. However, the fabric covering the front and the sides seems like it could rip or get dirty easily. The subwoofer is also made of plastic. For a better-built soundbar, check out the Samsung HW-Q65T or the Vizio M Series M512a-H6.

Design
In The Box
HDMI Cable Length
1.9 m (6.2 ft)
Digital Optical Cable Length
1.5 m (4.9 ft)

  • 2x power cables
  • 3.5mm to 3.5mm audio cable
  • Stereo RCA to 3.5mm audio cable
  • 2x Surround Speaker audio cables
  • Optical cable
  • HDMI cable
  • 4x Cable ties
  • Remote with batteries (2x AAA)
  • Wall Mount template
  • 4x Wall Mount brackets
  • 4x Wall Mount screws
  • User Manual

Sound
8.5
Sound
Stereo Frequency Response
Tested Preset
Direct
Slope
-0.41
Std. Err.
2.58 dB
Low-Frequency Extension
27.5 Hz
High-Frequency Extension
19.9 kHz

Out-of-the-box, the Vizio M51a-H6 has an excellent stereo frequency response. It has a very neutral sound profile, suitable for listening to lots of different types of audio content. There's a little extra boom in the bass range that can please fans of bass-heavy music like EDM and hip-hop, too.

8.5
Sound
Stereo Frequency Response With Preliminary Calibration
Suggested Preset
Direct
Suggested Bass Setting
0
Suggested Treble Setting
0
Slope
-0.41
Std. Err.
2.58 dB
Low-Frequency Extension
27.5 Hz
High-Frequency Extension
19.9 kHz

The Vizio M51a-H6 comes with bass and treble adjustments, as well as EQ presets to help you customize its sound profile to your liking. While we tested the bar in several different configurations, we found that its default sound profile offers the most neutral response.

7.0
Sound
Stereo Soundstage
Crosstalk Error
1.95 dB

The Vizio M Series 5.1 Soundbar has a decent stereo soundstage performance. The soundstage is perceived to be a little wider than the bar itself, but it doesn't have any tricks to make it sound wider than that. It has good focus, though, so objects in the soundstage seem to come from an accurate location rather than a general area.

8.1
Sound
Stereo Dynamics
SPL @ Max Volume
97.2 dB SPL
DRC @ Max Volume
1.88 dB

The Vizio M51a-H6 has impressive stereo dynamics. It gets pretty loud, and there isn't a lot of compression at max volume, so it's a solid choice for listening to music at crowded parties or in large rooms.

8.0
Sound
Stereo Total Harmonic Distortion
Weighted THD @ 80dB
0.32
Weighted THD @ Max Volume
1.86

This soundbar's stereo THD performance is great. At normal listening volumes, the amount of THD is within good limits, resulting in clean and pure audio reproduction. There's a slight jump in THD when you play it at max volume, but this may not be audible with real-life content.

8.6
Sound
Center
Localization
Discrete
Slope
0.03
Std. Err.
2.36 dB
SPL @ Max Volume
94.1 dB SPL
Weighted THD @ 80dB
0.40
Weighted THD @ Max Volume
1.69

The Vizio M51a-H6 is a 5.1 setup with an amazing center channel performance. Due to its configuration, it has a dedicated center speaker that can reproduce dialogue more clearly and accurately. It can get pretty loud, too.

7.5
Sound
Surround 5.1
Localization
Discrete
Slope
-0.64
Std. Err.
4.05 dB
SPL @ Max Volume
93.1 dB SPL
Weighted THD @ 80dB
0.33
Weighted THD @ Max Volume
1.19
7.1 Rears
No

The Vizio M51a-H6 has a good surrounds performance. Its discrete surround speakers help to clearly and accurately represent objects like voices and footsteps in the surround stage. Its sound profile is also pretty neutral, though slightly bass-heavy, so audio content packs a little extra thump and punch.

5.9
Sound
Height (Atmos)
Localization
Phantom (Front Firing, Satellites)
Slope
-0.53
Std. Err.
3.83 dB
SPL @ Max Volume
85.5 dB SPL
Weighted THD @ 80dB
3.58
Weighted THD @ Max Volume
0.42

The Vizio M51a-H6 has a middling Atmos performance. Unlike the Vizio V Series V51x-J6, it uses front-firing speakers on its satellites to ricochet sound off the ceiling and back down to you to help create the illusion of height. However, it doesn't sound as real as dedicated down-firing speakers in a home theater setup.

7.0
Sound
Sound Enhancement Features
Room Correction
No
Dialogue Enhancement
Yes
Auto-Volume/Night Mode
Yes
Subwoofer Level Adjustment
Yes
Bass Adjustment
Yes
Treble Adjustment
Yes
EQ
Presets
Surround Level Adjustment
Yes
Rear Level Adjustment
No
Height Level Adjustment
No
Virtual Surround
Yes

The Vizio M51a-H6 has a decent selection of sound enhancement features. There are four EQ presets to help you customize its sound, including 'Movie', 'Music', 'Direct', and 'Game'. There's also a dialogue enhancement feature to help make voices sound more clear and crisp, as well as a TruVolume feature that balances out the volume level across different programs.

Connectivity
Connectivity
Physical Inputs - Bar
Optical Audio In
1
HDMI ARC
1 (shared)
HDMI Out
1 (shared)
Full HDMI In
1
Analog Audio In 3.5mm (Aux)
1
RCA In
No
USB for Files
1
Ethernet
No

The Vizio M51a-H6 has several inputs, including a 3.5mm AUX port that lets you connect older devices to the bar over a wired connection. There's also a Full HDMI In port, so you can use the bar as a hub between your different devices.

10
Connectivity
Audio Format Support - ARC
eARC
Yes
Dolby Atmos
Yes
Dolby Digital
Yes
Dolby Digital Plus
Yes
DTS
Yes
DTS:X (eARC only)
Yes
Dolby TrueHD (eARC only)
Yes
DTS-HD MA (eARC only)
Yes
5.1 PCM (eARC only)
Yes

Over its HDMI ARC port, this soundbar supports lots of different audio formats. It supports Dolby Digital and DTS, which are two of the most common formats found on streaming platforms and Blu-ray discs. It even supports higher-end formats like Dolby Atmos.

10
Connectivity
Audio Format Support - Full HDMI In
Dolby Atmos
Yes
DTS:X
Yes
Dolby Digital
Yes
Dolby Digital Plus
Yes
DTS
Yes
Dolby TrueHD
Yes
DTS-HD MA
Yes
5.1 PCM
Yes

The Vizio M51a-H6 also has incredible sound format support via Full HDMI In. You can playback surround sound formats commonly found on streaming platforms like Netflix and Hulu like Dolby Digital and DTS.

10
Connectivity
Audio Format Support - Optical
Dolby Digital
Yes
DTS
Yes

The Vizio M51a-H6 also supports Dolby Digital and DTS content through its Optical In port. These formats are commonly found on streaming platforms as well as Blu-ray discs.

9.5
Connectivity
Latency
ARC
-23 ms
Optical
-8 ms
Full HDMI In
22 ms

The Vizio M51a-H6 has a fantastic latency performance. It has low latency via its ARC, Optical, and Full HDMI In ports, so it's a solid choice for watching videos and movies. However, some apps and some TVs compensate for latency differently, so your real-world experience may vary.

6.0
Connectivity
Wireless Playback
Bluetooth
Yes
Wi-Fi
No
Chromecast built-in
No
Apple AirPlay
No

You can stream audio wirelessly from your phone or your tablet to the soundbar via Bluetooth.

Connectivity
Other Input Specifications
4k @ 60 Hz Passthrough
Yes
4k @ 60 Hz @ 10 bit Passthrough
Yes
4k @ 60 Hz @ 4:4:4 Passthrough
Yes
HDR10 Passthrough
Yes

This soundbar can passthrough the highest bandwidth signals. When connected between your PC and your TV, text looks clear and crisp on your TV.

Connectivity
Connectivity - Subwoofer
Sub Wireless
Yes

The subwoofer wirelessly connects to the soundbar. However, there's a wired connection to each of the surround satellites as well as the power cable.

Connectivity
Connectivity - Satellites
Sat Wireless
Partial, wired to wireless sub

The satellites connect to the subwoofer over a wired connection, which may limit where you can place them in your room.

Additional Features
Additional Features
Interface
Display
No

There is a set of vertical lights on the left side of the bar that flashes depending on the settings you control and adjust. It also displays the volume level. There's audio feedback when you change between the different EQ presets and change the input.

Additional Features
Bar Controls

The Vizio M51a-H6 has several physical buttons on top of the bar. You can power the bar on/off, change the input, activate Bluetooth pairing mode, and adjust the volume.

Additional Features
Remote
Universal Remote
No

The remote is fairly simple and lets you control all of the bar's settings. It also has a display screen.

Additional Features
Voice Assistants Support
Amazon Alexa
No
Google Assistant
No
Apple Siri
No

If you want a soundbar with an AUX port for connecting third-party voice assistant devices, check out the Vizio M Series M51ax-J6.

Additional Features
App
App Name No App
iOS No
Android No
Acts As A Remote
No
Controls Soundbar's Settings
No
Casts Device Files
No
Additional Features
Other Features
Power Saving
Auto-off
HDMI CEC (TV Remote Control)
Yes

The Vizio M51a-H6 automatically shuts down after a period of inactivity when you enable its Eco Power mode. You can also disable this feature by holding the Power and Volume Down buttons for five seconds. Also, you can use your TV remote to control some of the bar's basic functions since it has HDMI CEC support.

Differences Between Sizes And Variants

The Vizio M51a-H6 is available in 'Black', and you can see the label for the model we tested here.

If you come across another version, let us know in the discussions so we can update our review.

Compared To Other Soundbars

The Vizio M51a-H6 is a 5.1 setup from 2020 that offers very versatile performance for a budget-level price. It has a balanced sound profile out-of-the-box with an extended low-bass, and its dedicated satellites offer a good surrounds performance. While it supports Dolby Atmos content, it doesn't offer a very immersive listening experience. See also our recommendations for the best soundbars, the best soundbars under $500, and the best Vizio soundbars.

Vizio M Series M512a-H6

The Vizio M Series M51a-H6 and the Vizio M Series M512a-H6 are similar. The M51a-H6 has lower latency via its ARC, Optical, and Full HDMI In ports, though some apps and TVs compensate for latency differently, and your experience may vary. That said, the M512a-H6 is better built, with a better soundstage performance. It also comes with two up-firing speakers.

Vizio M Series M51ax-J6

The Vizio M Series M51a-H6 is a better soundbar for mixed usage than the Vizio M Series M51ax-J6. The M51a-H6 offers a better latency performance over its ARC, Optical, and Full HDMI In ports. It also reproduces a more extended low-bass to help you feel thump and rumble. That said, only the M51ax-J6 has an AUX In port for connecting third-party voice assistant devices.

Sonos Arc

The Vizio M Series M51a-H6 is a better soundbar than the standalone Sonos Arc. The Vizio gets louder with less compression at max volume, and it has a more extended low-bass thanks to its dedicated subwoofer. Its satellites help create a more immersive surrounds experience. It also offers some EQ presets and a Full HDMI In port. However, the Sonos is better-built, with a better soundstage performance and a room correction feature. You may also want to compare this bar with the Sonos Arc with Sub + One SL Speakers.

Vizio V Series V51-H6

The Vizio M Series M51a-H6 is a better soundbar than the Vizio V Series V51-H6. The M Series has a more neutral sound profile out-of-the-box, and it has a better surrounds performance. It also supports Dolby Atmos content, and because it comes with a Full HDMI In port, it can support 4k passthrough.

Vizio SB36512-F6

The Vizio M Series M51a-H6 is a better soundbar than the Vizio SB36512-F6. The M Series has a more neutral sound profile out-of-the-box, and it can get louder. It has a better surrounds performance, more sound enhancement features, and it supports DTS:X. However, the SB36512-F6 is Wi-Fi compatible and has Chromecast built-in.

Vizio Elevate

The Vizio Elevate and the Vizio M Series M51a-H6 are both very versatile soundbars, and depending on your listening habits, you may prefer one over the other. The Elevate has a unique design with sides that rotate upwards to create a more immersive listening experience. It's better-built, it has a better stereo soundstage performance, and it supports Wi-Fi and Chromecast built-in. However, the M Series has a better surrounds performance, and there's less compression present when you play it at max volume.

Vizio SB46514-F6

The Vizio M Series M51a-H6 is better than the Vizio SB46514-F6. The M51a-H6 has more sound enhancement features, including dialogue enhancement. It also has more extended low-bass, and a better center performance. However, the SB46514-F6 has a better Atmos performance. It's also better-built with more wireless playback options.

Samsung HW-Q950A

The Samsung HW-Q950A is better than the Vizio M Series M51a-H6. The Samsung is an 11.1.4 setup that's better built and gets louder. It has better soundstage, surround, and Atmos performances, too. There are also more sound enhancement features, like room correction and a graphic EQ. It supports more wireless playback options than the Vizio, and it also comes with built-in voice assistant support.

Sonos Beam

The Vizio M Series M51a-H6 is better than the Sonos Beam. The Vizio is a 5.1 setup with a dedicated sub that helps reproduce a more extended low-bass. Thanks to its satellites, it also has a better surround performance. Unlike the Sonos, it supports Atmos content and comes with EQ presets as well as a Full HDMI In port. That said, some listeners may prefer the Sonos' better-built, more compact design. Unlike the Vizio, the Sonos has room correction and built-in voice assistant support. Its stereo soundstage performance is better, too.

Samsung HW-A650

The Vizio M Series M51a-H6 is better than the Samsung HW-A650. The Vizio is a 5.1 setup that supports Dolby Atmos content and comes with discrete satellites, unlike the Samsung. It also reproduces a more extended low-bass, and it has a better surrounds performance. However, the 3.1 Samsung is better-built, and some users may prefer its graphic EQ for sound customization.

Vizio M-Series M21d-H8R

The Vizio M Series M51a-H6 is better than the Vizio M-Series M21d-H8R. The M51a-H6 is a 5.1 setup with a dedicated sub and two satellite speakers. It has better soundstage, center, and surround performances, and it supports Atmos content. It also gets louder with much less compression at max volume. However, the 2.1 M21d-H8R is better built.

Samsung HW-Q600A

The Vizio M Series M51a-H6 is better than the Samsung HW-Q600A. The Vizio is a 5.1 setup that comes with discrete satellite speakers and offers better surround and Atmos performances. It also reproduces a more extended low-bass, so you feel more thump and rumble in your audio. That said, the Samsung is better-built. Unlike the Vizio, it has a graphic EQ to help you customize its sound.

Sonos Arc with Sub + One SL Speakers

The Sonos Arc with Sub + One SL Speakers is better for most uses than the Vizio M Series M51a-H6. The Sonos is better-built, with better soundstage, surround, and Atmos performances. Unlike the Vizio, it has room correction and built-in voice assistant support. That said, some listeners may prefer the Vizio's more neutral sound profile out-of-the-box. The Vizio also has a Full HDMI In port that supports high quality passthrough, unlike the Sonos.

JBL Bar 5.1 Surround

The Vizio M Series M51a-H6 is better than the JBL Bar 5.1 Surround. The Vizio comes with dedicated satellites, and it supports Dolby Atmos content. It gets louder with less compression at max volume, and it has better soundstage and surround performances. That said, the JBL is better built with more wireless playback options.

LG SP8YA

The Vizio M Series M51a-H6 is better than the LG SP8YA. The Vizio is a 5.1 setup with discrete satellites, so it offers a better surrounds performance. However, the 3.1.2 LG is better built with more wireless playback options. Unlike the Vizio, it also has room correction.

Vizio V Series V51x-J6

The Vizio M Series M51a-H6 is a better soundbar than the Vizio V Series V51x-J6. The M Series supports Dolby Atmos content and offers a better surround performance. It also reproduces a more extended low-bass. Unlike the V Series, it comes with a Full HDMI In port that supports high-quality passthrough. However, only the V Series comes with an AUX In port for voice assistant-enabled devices.

Samsung HW-Q65T

The Vizio M Series M51a-H6 is a better soundbar than the Samsung HW-Q65T. The Vizio has a more extended low-bass and a more neutral sound profile out-of-the-box. Also, it supports Dolby Atmos content. However, the Samsung is better-built and comes with a graphic EQ for sound customization.

JBL Bar 9.1

The Vizio M Series M51a-H6 is better than the JBL Bar 9.1. The Vizio reproduces a more extended low-bass, so you feel more thump and rumble in your audio. It gets louder, and it has a dialogue enhancement feature. However, the JBL is better-built with more wireless playback options. It has a better soundstage and a room correction feature.

Samsung HW-T650

The Vizio M Series M51a-H6 is a better soundbar than the Samsung HW-T650. The Vizio is a 5.1 setup with a better surrounds performance that also supports Atmos and DTS:X content. It also has a more extended low-bass, and it can support 4k passthrough. However, the Samsung is better built and offers a better stereo soundstage performance.

Monoprice SB-600

The 5.1 Vizio M Series M51a-H6 is a better soundbar than the 5.1.2 Monoprice SB-600. The Vizio has a much more neutral sound profile, and it can produce a more extended low-bass. It gets louder than the Monoprice with less compression present at max volume. Also, it provides a more immersive surround sound experience. Although the Monoprice has slightly less distortion when used at max volume, there likely isn't a noticeable difference for real-life content.

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