Vizio M55Q6 Quantum 4K HDR TV Review

Published On: December 16, 2021
We May Earn From Purchases Via Links

Vizio M55Q6 Quantum 4K HDR TV Review

The Vizio M55Q6 Quantum has very good out-of-the-box performance, but there are areas where it is a step behind some of its competitors.

Vizio M55Q6 Quantum 4K HDR TV Review

By Author: John Higgins
John Higgins been a part of the AV industry since 2003, when he started working at the test studio for Home Theater Magazine, and later Sound & Vision. He’s since written for Wirecutter, IGN, Channel Guide Magazine, ProjectorCentral, and Cineluxe. When not focusing his attentions on whatever display or speakers he’s presently reviewing, John is probably either playing with his son or lost in a computer screen, working on his latest sound design, sound editing, film composition project.

Vizio has long been a purveyor of electronics that over-perform their price point. It seems as though it was their prime directive when they were founded almost two decades ago. Their first few years of existence were a tad rocky, as far as their consistent TV quality, but that is now a distant memory as they’ve been putting out some really good displays for years, across price ranges and—with their OLED release last year—across technologies, too. 

The M-Series is Vizio midrange TV, falling below their top-end P-Series and above the V-Series. Of the M-Series, the Q6 is the cheaper of the two models (with the recently-reviewed Q7 being the more expensive). The main differences between the Q6 and Q7 are the gaming engine used (V-Gaming Engine on the Q6 and ProGaming Engine on the Q7, although both have FreeSync) and the dimming zones, of which the Q6 doesn’t have any (it’s a full-array backlight TV). The question is whether or not the few hundred dollars saved are worth those sacrifices. 


When quantum dot technology first came out, it was reserved for higher-priced sets (as new technology generally is), but since last year’s models, the Vizio M-series has employed quantum dot technology (see, it’s right there in the name). The quantum dots are a photoemissive layer that improves the picture in (possibly) two ways. When the backlight hits the quantum dot layer, the dots, in turn, emit their own light, which is determined by the size of the dot (from small to large it’s blue, green, red). It’s a tad more complicated than that, but for all intents and purposes, this works. This increases the potential for accurate color and a wider color gamut, which is usually attached to HDR. The extra light emitted by the dots can also help boost the overall light output of the TV (although much of that still depends on the LED backlight output). 

Smart TV Capabilities 

As with the Q7, the M55Q6 runs on Vizio’s SmartCast OS. There are all of the expected streaming options here—including Disney+, Netflix, and Amazon. And if the content has a Dolby Vision version, it is supported by the M55Q6. In addition, across the top of the screen are ways to access movies, shows, and a Vizio exclusive—Watchfree+. The interface looks like a cable or satellite guide and includes news channels like CNN and NY or LA local CBS News stations, movie channels like Hallmark, The Walking Dead Universe, and Dust (which plays short films like Live, sound designed by yours truly), and even a channel devoted to Gordon Ramsey’s Hell’s Kitchen and Kitchen Nightmares. All of the supported apps come pre-installed on the TV, which is good because there doesn’t seem to be an external store to download them from. 

Built-in to the SmartCast OS is the ability to cast content from your mobile devices to the TV (again, right there in the name). The M-series supports Apple AirPlay and Chromecast. Both work extremely well and function easily. 

Setting Up the Vizio M55Q6 Quantum 

The M55Q6 has suitably thin bezels that keeps the design more about the picture than about the frame. The bottom bezel is slightly thicker than the other three sides and has a Vizio badge on the far right. The stands can only be attached at wide points. This leads to a sturdy TV, but does require a table or credenza that is at least 45-inches wide to hold the TV (although for anxiety’s sake, I’d make sure that table is a bit wider). 

The back of the TV is made a combination of aluminum and hard plastic that’s around the connection panels. 200x300mm VESA mounting points are on the back. The connection panels (one side-facing and one rear-facing) are around the right side of the TV and the hard-wired power cable is around the left side. There are no clips or built-in cable troughs for management. 


The side-facing connections are three HDMI 2.1 (one with eARC) and a USB 2.0 that can provide power for a streaming stick if you choose to use one instead of the SmartCast OS interface. While at first glance the inclusion of HDMI 2.1 might excite gamers, it’s important to note that the TV has a native 60Hz panel, so the TV is unable to fully take advantage of a 4K/120Hz signal from a PS5 or Xbox Series X. The rear-facing ports are an RF for an antenna, stereo RCA audio in and out, composite video in, optical audio out, and Ethernet (you can also connect via Wi-Fi). 


No one, in my opinion, should ever rely on TV speakers for anything near an immersive audio experience. Physics just won’t allow it. Some TVs do better than others (I find Sony TVs in particular to have pretty decent sound), but the M55Q6 is not one of them. It’s far from the worst audio performance I’ve heard, but I still highly recommend getting a soundbar at least to pair with the TV. Luckily Vizio has a selection of some excellent options that will match the design of the M-series. 

Interface and Control Settings 

The Vizio SmartCast interface has improved over the past couple of years, partly thanks to the IQ Active processor Vizio introduced last year. The interface’s response is quicker and smoother, although I still ran into the occasional pause or stutter. Menu navigation is easy for picture setup (calibration and to turn off pesky motion smoothing). 

The included remote has a mic for voice control capabilities that work reasonably well. The new remote is slim, light, and relatively limited (in a good way) on buttons. Six dedicated app buttons are at the top of the remote for Peacock, Netflix, Amazon Prime Video, Disney+, Crackle, and Tubi as well as one for the WatchFree+ service. They’re a little small and close together, so someone with larger fingers might have some difficulty pressing just one at a time. Beyond that, there’s a home, settings, back, CC, and mic activation button around a directional pad. Volume and mute are at the bottom of the remote. It’s all intuitive to navigate. 

How Does the Vizio M55Q6 Perform? 

It used to be in years past that cheaper TVs translated to a significant drop in color and grayscale accuracy and performance. While that still holds true for the no-name low-end brands, when you hit the $400 mark on 55-inch models, performance out of the box is pretty good. That’s the case with the Vizio M55Q6, which bears out in the measurements. 

I used my X-Rite i1Display Pro colorimeter profiled to a X-Rite i1 Pro 3, a Murideo Six-G pattern generator, and Portrait Display’s Calman color calibration software to measure the M55Q6. Before calibration, both the grayscale and color accuracy had DeltaE values of 2.5 and 2.2, respectively, in Calibrated Dark picture mode. (DeltaE is the numerical indication of how close to perfect a value is, with lower being better. At values below 3.0 it is difficult to discern any issues without a perfect example alongside the image.) The biggest problem with the grayscale is that the mid-tone grays were a bit too bright, which can rob the picture of some dimensionality. This comes across in the gamma curve, which falls below the 2.2target—closer to a 1.9—in those mid-tones. But in truth, this wasn’t a huge issue.  

Display brightness before calibration was a little below 300 nits, in both SDR and HDR. This is fine for SDR signals but is disappointing for HDR, which really needs at least twice this brightness to have a good effect. Black level is decent for its price range, but there’s no local dimming feature on the Q6. 

After calibration, the Vizio measured near perfect. Controls were easy to access to complete the calibration. Now the question is, is spending a few hundred dollars on a $580 TV worthwhile? Personally, I’d say the out-of-the-box performance is good enough that the extra calibration money would be better spent on either an upgrade on the TV or a decent soundbar (sorry, calibrators). 

A go-to disc for me over the past year has been the recently released Lord of the Rings 4K Blu-ray set. The transfers look absolutely amazing and there are so many scenes that can show off how good (or bad) a TV performs. One of those is when Frodo enters Shelob’s lair in Return of the King. It’s a dark scene, but still well lit so the crevices in the rock sides of the tunnel can be made out on a display with good contrast. On the Vizio, the shadows were closer to gray than black, and because of it there wasn’t as much depth to the scene as I’ve seen before. Part of that is because the M55Q6 doesn’t have local dimming, so it doesn’t have the ability to make greater differentiation between the lighter and darker sections of the cave as well. Its blacks are better on scenes where the vast majority of the screen is black, so as full space shots in The Expanse (although this causes another problem that I’ll address in The Downside below). 

The HDR presentation of both Lord of the Rings and The Expanse was lacking. There was no discernable pop to the image. It was maybe slightly better than SDR, but not in any great way. Dolby Vision titles—both through the SmartCast OS and my Roku Ultimate—had a slightly more dynamic look to them, but the limiting factor of a real “wow” performance was the overall brightness the Vizio is capable of. 

Color in both SDR and HDR looked great. The forest around Rivendell in The Fellowship of the Ring looked rich and vibrant, as does the variation in browns, reds, and grays of the bridges and buildings. Skin tones are natural with nobody looking sick or sunburned. 

The great color continues in gaming, with death scenes in Mortal Kombat 11 especially gruesome. The input lag is nice and low—I measured the 1080p lag at 13.9 ms with my Leo Bodnar lag tester—and with FreeSync on the Xbox Series X, I didn’t notice any screen tearing (FreeSync is not supported on the PS5). As mentioned above, the Vizio has a native 60Hz panel so it is incapable of displaying games at a high refresh rate. Still, the gaming experience looked really good and felt nice and responsive. 

HDR Issues

For a couple of years, one of the biggest buzzwords in the television world has been HDR—and rightfully so as it can really make an impact on the overall image quality perception. But this is where lower midrange TVs tend to suffer and the M55Q6 is, unfortunately, no exception in this regard. There just isn’t enough light output for HDR material to give that pop that is the hallmark of good HDR. 

As mentioned, the M55Q6 is a full-array backlight TV and doesn’t have local dimming capabilities, so while its black level is good (especially for the price range), there’s still some pretty evident bloom around bright images. This is most prominent in scenes like external space shots in The Expanse, where the light from a ship’s engine will extend out into the blackness of space, or the glow of a planet’s atmosphere creates an extended bloom, or with blocks of white text against a dark background. 

Comparison and Competition 

The two direct comparisons to the Vizio M55Q6 are the TCL 55S535 and the Hisense 55U6G. Both of them have an edge over Vizio because they have local dimming. The Hisense can also get brighter than the Vizio, so the HDR material on it has more pop—although still not truly great HDR. Color performance out of the box on all three is very good with the slight edge going to the Vizio. And the Vizio is the only one of the three that has a variable refresh rate (in the form of FreeSync). Beyond that, they are all very similar with 60Hz native panels and low input lag. 

So it really depends on where your interests lie. At this price point, the Vizio is a bit more tuned to gaming with the inclusion of FreeSync, but the overall image on both the TCL and the Hisense is better thanks to more light output. As much as I enjoy gaming, I personally would go with the Hisense because the better picture outweighs my need for variable refresh rate. 

Final Thoughts 

Vizio has been providing really good TV across all price ranges for a while now (their P-series has included some of my favorite LED TVs in the past), and the M55Q6 is a really good TV. Color and grayscale out of the box are great and you can get by without calibration, it has FreeSync VRR and low input lag for gamers, and it supports all versions of HDR including Dolby Vision. 

But with limited brightness, does having Dolby Vision really pay off as it should? And is the lack of local dimming too much to overcome its competitors? For me the answer is “not quite.” The Vizio M55Q6 is a good TV, but it’s just short of being in step with other TVs in its class. 

Subscribe To Home Theater Review

Get the latest weekly home theater news, sweepstakes and special offers delivered right to your inbox
Email Subscribe
© JRW Publishing Company, 2023
As an Amazon Associate we may earn from qualifying purchases.

linkedin facebook pinterest youtube rss twitter instagram facebook-blank rss-blank linkedin-blank pinterest youtube twitter instagram
Share to...