The Vizio M Series M51ax-J6 is a 5.1 setup that's the next generation of the Vizio M Series M51a-H6. On its 'Direct' preset, it has a very neutral, balanced sound profile suitable for listening to many different types of audio content. There are some EQ presets to help you customize its sound, and it gets pretty loud. It also supports Dolby Atmos content and comes with discrete surround speakers to help clearly represent surround objects in the sound image. That said, it lacks more premium sound enhancement features, like a graphic EQ or room correction.
Our Verdict
The Vizio M51ax-J6 is very good for mixed usage. This 5.1 setup offers a neutral, balanced sound profile suitable for listening to many different types of audio content. It gets pretty loud, too, and some sound enhancement features are available to help customize your listening experience. It even comes with discrete surround speakers and supports Dolby Atmos content. It lacks more premium sound enhancement features like room correction, and its Atmos experience isn't the most immersive.
- Bass and treble adjustments.
- Gets loud.
- Supports Atmos content.
- No graphic EQ.
- Fairly high latency.
The Vizio M51ax-J6 is great for dialogue-centric content like TV shows. Its balanced mid-range helps reproduce voices clearly and with detail, and its discrete center channel accurately localizes dialogue to a pinpoint location in the sound image. There's even a dialogue enhancement feature to make voices more clear and crisp and a TruVolume mode to balance the volume across different programs. That said, it only supports Bluetooth connectivity, which can be disappointing if you like to wirelessly stream podcasts and audiobooks to the bar via other connections.
- Bluetooth connectivity.
- Dialogue enhancement feature.
- Doesn't support Wi-Fi, Chromecast built-in, or Apple AirPlay.
The Vizio M51ax-J6 is good for music. With its 'Direct' preset, this soundbar has a very neutral, balanced sound profile suitable for listening to many different types of audio content. It gets pretty loud, too, and there are a few EQ presets and bass and treble adjustments to help you customize its sound. It lacks more premium sound customization features like a graphic EQ.
- Bass and treble adjustments.
- Gets loud.
- No graphic EQ.
The Vizio M51ax-J6 is very good for movies. Its neutral sound profile accurately reproduces the thump and rumble in action-packed scenes, and dialogue is clear and detailed. It also comes with discrete satellite speakers that help to more clearly represent surround objects when watching surround content. Also, it supports Dolby Atmos content, though it doesn't offer the most immersive listening experience.
- Gets loud.
- Supports Atmos content.
- Fairly high latency.
Changelog
- Updated Sep 04, 2024: Updated the Stereo Dynamics, Stereo Frequency Response With Preliminary Calibrations, and Surround 5.1 results with new methodology from Test Bench 1.3 and accompanying text. Added text to the Audio Latency: ARC, Audio Latency: HDMI In, and Audio Latency: Optical boxes.
- Updated Aug 28, 2024: We've converted this review to Test Bench Update 1.3. If applicable, we've retested stereo sound based on the manufacturer's recommendations. Additionally, we've expanded our audio latency tests to the following boxes: Audio Latency: ARC, Audio Latency: HDMI In, and Audio Latency: Optical. You can see the full changelog here.
- Updated Jan 05, 2024: Added market comparison for the Hisense AX5125H in the Sound Enhancement Features box.
- Updated Jun 13, 2023: Converted to Test Bench 1.2. Updated the results for audio format support via ARC/eARC, HDMI In, and Optical. Added Video Passthrough to TV results as well.
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Differences Between Sizes And Variants
The Vizio M51ax-J6 comes in 'Dark Charcoal', and you can see the label for the model we tested here.
If you come across another version, let us know in the discussions, and we'll update our review.
Popular Soundbar Comparisons
The Vizio M51ax-J6 is a 5.1 setup released in 2021 that's the next generation of the Vizio M Series M51a-H6. As part of the M Series lineup, it offers a slightly better overall performance compared to the more budget-friendly V Series. It even supports Dolby Atmos content, unlike the Vizio V Series V51x-J6. That said, it doesn't offer as many premium sound enhancement features as the Vizio Elevate.
See our recommendations for the best soundbars under $500, the best Dolby Atmos soundbars, and the best Vizio soundbars.
The Vizio M Series M51ax-J6 is slightly better than the Vizio M Series M512a-H6 if you watch a lot of 5.1 surround sound content or play audio loudly. However, the M512a-H6 is better for music, has a better soundstage, and is better built, with slightly greater passthrough capabilities. It even comes with two up-firing speakers.
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 port, though HDMI In has higher latency. It also reproduces a more extended low bass to help you feel thump and rumble.
The Vizio M Series M51ax-J6 has a better performance than the Vizio V Series V51-H6. The M Series supports Dolby Atmos content and has a better surround performance. Unlike the V Series, it has a Full HDMI In port supporting high-quality passthrough.
The main difference between the Hisense AX5125H and the Vizio M Series M51ax-J6 is the number of height channels. While the Hisense has two up-firing channels built into the bar to simulate height with content like Dolby Atmos, the Vizio relies on front-firing channels to perform a similar function. Still, there isn't much difference between the two's overall immersive feel. The Vizio ranks higher because it has more sound enhancement features and offers better latency.
The Vizio M Series M51ax-J6 is better for mixed usage than the Vizio SB36512-F6. The M Series has better surround performance and comes with more sound enhancement features, like dialogue enhancement and greater audio format support. It also has an AUX VA In port for connecting third-party voice assistant devices. However, the SB36512-F6 has more wireless playback options.
The Vizio M Series M51ax-J6 and Amazon Fire TV Soundbar Plus with Sub + Speakers are similar 5.1-channel soundbars with external subwoofers and satellite speakers. The Amazon is built better and reaches similar levels at max volumes in individual channel tests. That said, the Vizio is priced more competitively and supports PCM-7.1 channel input via HDMI and can pass through 4k @ 120Hz video.
The Vizio M Series M51ax-J6 is better than the onn. 42" 5.1. 2. Dolby Atmos Soundbar. They're both affordable 5.1.2 setups with Atmos support, but the Vizio soundbar's Atmos performance is better. The Vizio comes with discrete satellites for a better surround sound, too. More sound enhancement features are also available, and DTS support, which the onn. lacks.
The Vizio M Series M51ax-J6 is better for mixed usage than the Vizio SB46514-F6. The M Series is a 5.1 setup with a better center channel performance and more sound enhancement features, including dialogue enhancement with greater support for different audio formats. That said, the SB46514-F6 is better built and has a slightly better Atmos performance.
The Vizio M Series M51ax-J6 is better than the Samsung HW-A650. The Vizio is a 5.1 setup with discrete satellites; it offers better surround performance. Unlike the Samsung soundbar, it supports Atmos content and can reproduce a slightly more extended low bass. However, the 3.1 Samsung is better built and has a graphic EQ.
The Vizio M Series M51ax-J6 is a better soundbar than the Vizio V Series V51x-J6. The M Series reproduces a more extended low bass and offers a better surround performance. Unlike the V Series, it supports Dolby Atmos content and has a Full HDMI In port.
The Vizio M Series M51ax-J6 is a 5.1 Dolby Atmos soundbar just like the Samsung HW-Q67CB. They're similar, but the Vizio is better overall. It reproduces more bass, so you feel more thump and rumble in music and movies. There's less compression as you crank up the volume, too. It doesn't have a graphic EQ like the Samsung, but there are still bass and treble adjustments to give you some control over its sound.
The Vizio M Series M51ax-J6 is better than the Vizio M Series M215a-J6. They're both 2021 models from the manufacturer, but the M51ax-J6 is a 5.1 setup and comes with two rear satellites. As a result, it performs much better with surround and Atmos content, and it has a center channel to improve vocal clarity. It's pricier than the M215a-J6, so if you mostly listen to music, you may want to stick with the cheaper model. However, the M51ax-J6 is a more versatile soundbar.
The JBL Bar 9.1 and the Vizio M Series M51ax-J6 are both very versatile 5.1 soundbars with Dolby Atmos support. The JBL offers a better soundstage, and its surround performance is a bit better. That said, the Vizio offers a better value if you're shopping on a budget.
The Vizio M Series M51ax-J6 is better than the Samsung HW-Q59CT. The Vizio supports Dolby Atmos content and has better center and surround performances. It also reproduces a more extended low bass. However, the Samsung is better built and has a graphic EQ.
The Vizio M Series M51ax-J6 is better than the Polk Audio MagniFi MAX SR. The Vizio is a 5.1 setup with better surround sound performance. Unlike the Polk, it also supports Dolby Atmos content and has more sound enhancement features.
The Vizio M Series M51ax-J6 is better than the Samsung HW-A550. The Vizio is a 5.1 setup that comes with discrete satellites. Unlike the Samsung, it supports Dolby Atmos content. It has a better surround performance and can reproduce a more extended low bass. That said, the 2.1 Samsung is still a good choice for vocal-centric content like TV shows and music.
The Vizio M Series M51ax-J6 is a better soundbar than the standalone Sonos Arc. The Vizio reproduces a more extended low bass and offers a better surround performance. It also comes with EQ presets for sound customization and a Full HDMI In port, unlike the Sonos. The Sonos is better built with better soundstage and Atmos performance. It also can be upgraded to the Sonos Arc with Sub + One SL Speakers for better performance. It also has built-in voice assistant support, whereas the Vizio only supports voice assistants when you connect a third-party device.
The Vizio M Series M51ax-J6 is better than the Samsung HW-Q600A. The Vizio is a 5.1 setup with discrete satellites. It has better surround performance and can reproduce a more extended low bass. Also, it gets louder, with a bit less compression, when you push it to max volume. That said, the 3.1.2 Samsung is better built. There's also a graphic EQ available, which some listeners may prefer for sound customization.
The Vizio M Series M51ax-J6 is better than the Samsung HW-Q700A. The Vizio is a 5.1 setup with discrete satellites. It can reproduce a more extended low bass and has better surround performance. Also, it gets louder with less compression at max volume. That said, the 3.1.2 Samsung is better built and has a slightly better soundstage.
Depending on your listening habits, you may prefer either the Vizio M Series M51ax-J6 or the Samsung HW-Q800A. The Vizio is a 5.1 setup with discrete satellites. It has a much better surround performance. However, the 3.1.2 Samsung is better built with a better soundstage and a frequency response that suits dialogue well. It even comes with built-in voice assistant capabilities.
Depending on your listening habits, you may prefer either the Vizio M Series M51ax-J6 or the Samsung HW-Q850A. The Vizio is a 5.1 setup that gets louder with less compression at max volume. It also has better center channel performance. However, the 5.1.2 Samsung is better built and has better soundstage, surround, and Atmos performance.
The Vizio M Series M51ax-J6 is better than the Samsung HW-Q65T. Unlike the Samsung, the Vizio supports Dolby Atmos content. It also reproduces a more extended low bass and has a better center channel performance. That said, the Samsung is better built.
Depending on your listening habits, you may prefer either the LG SP9YA or the Vizio M Series M51ax-J6. The LG is a 5.1.2 setup with a better soundstage and more sound enhancement features, including room correction. The Vizio has a better surround performance thanks to the included satellites. While you can purchase satellites for the LG separately, the Vizio offers a better value overall.
The Vizio Elevate is a slightly better soundbar than the Vizio M Series M51ax-J6. The Elevate is better-built, with a unique design that features rotating sides to help create a better soundstage performance. It also comes with more wireless playback support. However, it exhibits higher latency and a smaller stereo soundstage than the M Series M51ax-J6.
The Vizio M Series M51ax-J6 and the Vizio M-Series M21d-H8R are very different soundbar setups. The M21d-H8R is a 2.1 standalone soundbar that's ideal for listening to vocal-centric content like TV shows. That said, the M51ax-J6 is better overall. It's a 5.1 bar with Dolby Atmos support that can reproduce a more extended low bass thanks to its dedicated sub. Its satellites offer a better surround performance, too, and it has a better soundstage.
Test Results
The Vizio M51ax-J6 is a soundbar with a simple, sleek design. The bar is mostly made of plastic, and there's a thin fabric covering the front and the sides.
The sub sits on four plastic pegs with rubber grips. It's mostly made of melamine, and the port is located in the rear. The speaker is located underneath.
The satellites have a similar design to the bar. They're mostly plastic, with a thin fabric covering the front and the sides. They need to be wired to the sub to function. If you don't have room in your setup for satellites, you can always check out an option that comes without them, like the Vizio M Series M215a-J6.
The Vizio M51ax-J6 isn't very wide, but it may not fit between the legs of a 55" TV stand. That said, it also isn't very tall, so it shouldn't obscure your TV screen unless your TV sits flush on the table.
The sub is roughly the same size as that of the Vizio M Series M51a-H6. It's a bit shorter than the average desktop PC.
The satellites are fairly small. You only need to plug them into the sub to get them to work, so you have some flexibility when placing them in your setup.
The Vizio M51ax-J6 has a decent build quality. It has a very similar look and feel to the Vizio M Series M51a-H6. The bar and the satellites are mostly made of matte-textured plastic, which feels solid and durable overall. However, the fabric coverings on the front and sides seem like they could rip or collect dust easily. The sub is mostly made of melamine, which feels solid. For a better built soundbar, check out the Samsung HW-Q59CT.
- Manuals
- Mounting template
- 4x wall mount brackets
- 4x wall mount screws
- Remote with batteries (2x AAA)
- 2x power cable (8.5 ft / 2.6m and 4.9 ft / 1.5m)
- 2x surround speaker audio cable (26 ft / 8.0m)
- Optical cable (4.9 / 1.5m)
- HDMI cable (6.2 ft / 1.9m)
- 4x cable ties
The Vizio M51ax-J6 has a very good stereo frequency response. With its 'Direct' preset, it has a neutral, balanced sound profile that's suitable for listening to lots of different types of audio content, though it's a bit bassy. While we noticed some port noises and rumbling in the low bass, this may be unique to our testing unit. You can also customize its sound using the EQ presets as well as the bass and treble adjustments.
The Vizio M51ax-J6 comes with bass and treble adjustments, and EQ presets to help you customize its sound profile. While we tested the bar in several configurations, we found that bass at '-3' offers the most neutral response.
The Vizio M51ax-J6 has a decent stereo soundstage performance. The soundstage is perceived to be a little bit wider than the bar itself, but it doesn't have any tricks to make it seem wider than that. It has good focus, though, so objects in the soundstage, like voices, seem to come from a pinpoint location rather than a general area.
The Vizio M51ax-J6 has excellent stereo dynamics performance. This soundbar gets pretty loud, and there isn't much compression when you push it to the maximum volume. You can crank up the volume to fill large spaces and crowded parties, and audio reproduction remains mostly clean.
The Vizio M51ax-J6 has a great center channel performance. This 5.1 setup has a discrete center channel that helps accurately localize voices to a pinpoint location in the sound image. It also has a neutral frequency response, especially in the mid-range, where dialogue reproduces, so voices are clear and detailed.
The Vizio M51ax-J6 has a good 5.1 surround performance. Thanks to its discrete surround speakers, surround objects like voices are clearly and accurately represented in the soundstage. Its frequency response is slightly bass-heavy, so audio content has extra thump and punch.
The Vizio M51ax-J6 has a middling Atmos performance. It uses front-firing speakers on its satellites to bounce sound off the ceiling and back down toward you to create the illusion of height. However, this doesn't sound as real as discrete down-firing speakers in a home theater setup.
The Vizio M51ax-J6 has a decent selection of sound enhancement features, especially compared to similarly-priced models like the Hisense AX5125H. There are some EQ presets so you can customize its sound, including 'Direct', 'Movie', 'Music', and 'Game'. You can use the dialogue enhancement feature to make voices more clear and crisp, and the TruVolume feature provides a consistent volume level across programs. However, it lacks more premium features like a graphic EQ or room correction, so it may sound a bit different depending on the room you're listening in.
The Vizio M51ax-J6 has several inputs. There's a Full HDMI In port, so you can use it as a hub between different devices. You can also use the AUX In port to connect older devices for audio playback.
The Vizio M51ax-J6 supports all of the audio formats that we test for via ARC. It supports Dolby Digital content, which is the most commonly found surround sound format. It also supports lossless and object-based surround formats like Dolby Atmos.
We received feedback from a user who experienced issues playing LPCM content over Apple TV and Xbox. However, we weren't able to replicate this phenomenon in our tests. We confirmed that the bar can playback 5.1 PCM.
The Vizio M51ax-J6 has incredible audio format support via Full HDMI In. It supports surround sound formats commonly found on streaming platforms and Blu-ray discs like Dolby Digital and DTS.
We received feedback from a user who experienced issues playing LPCM content over Apple TV and Xbox. However, we weren't able to replicate this phenomenon in our tests. We confirmed that the bar can playback 5.1 PCM.
The Vizio M51ax-J6 also supports both Dolby Digital and DTS content via Optical. You can often find these formats on streaming platforms and Blu-ray discs.
The soundbar has fantastic ARC latency with most formats. ARC over Dolby Digital has fairly low latency, while object-based surround sound, Dolby Atmos, and Dolby Atmos Plus, which tend to have higher latency, still have relatively low latency. 5.1 PCM has the highest latency out of the formats, but latency can vary somewhat, and you can compensate with some apps or your TV's settings.
The HDMI In audio latency is alright. PCM formats have the lowest latency, while Dolby Digital has the highest latency. You'll notice a bit of sync mismatch between the audio and video over all formats, more so Dolby Digital and Dolby Atmos formats than PCM, which may require using the TV settings or apps to compensate, though your real-world experience can vary.
The soundbar's audio latency over Optical is satisfactory. However, the lag of both PCM and Dolby Digital is high enough that you'll notice a mismatch between the video and audio. Some TVs and apps can compensate for this lag, and your experience can vary.
This soundbar can passthrough high bandwidth signals, including select 4k at 120Hz in select modes and even 8k at 60Hz. When connected between your PC and your TV, text on the screen appears clear and crisp.
The Vizio M Series M51ax-J6 only supports Bluetooth connectivity, so you can wirelessly stream audio from mobile devices to the bar over this connection.
There's a set of vertical lights on the left side of the bar that flash different patterns depending on the settings you adjust. It also displays the volume level. Also, you get audio feedback when switching between the different preset modes and inputs.
Several physical buttons on the top of the bar let you power it on/off, change the input, enter Bluetooth pairing mode, and adjust the volume.
The remote is fairly simple and lets you control all the bar's settings, including the volume and the EQ preset.
This soundbar doesn't have built-in voice assistant support. You can plug in a voice assistant-enabled device like an Amazon Echo using the AUX VA In port. However, since this requires purchasing a third-party device, we don't test for it.