Vizio M-Series Quantum X 50-inch Class 4K TV review

In creating the Vizio M-Series Quantum X, Vizio was attempting to bring much of the same technology found in its popular — but expensive — Vizio P-Series Quantum X to a more affordable screen. By working in quantum dots with full array local dimming, a 120Hz native refresh rate and HDMI ports with the latest spec, the M-Series Quantum X checks all the boxes. That said, its bulky body and less-than-ideal peak brightness hold it back from beating other top-performing TVs at this price range.

But where does it stand against the competition? Similarly priced screens will be missing many of the M-Series Quantum X’s key gaming features: a native 120Hz refresh rate with HDMI 2.1 ports and support for Dolby Vision Gaming. On the flip side, though, other screens from TCL that cost around the same do have a bit better HDR performance and less bulky design, so there are trade-offs to be made here.

Ultimately you’ll want the M-Series Quantum X if you’re looking for great gaming performance on a budget and a decent smart platform, and you don’t mind the bulkiness of the screen or the lackluster peak brightness.

Vizio M-Series Quantum X 50-inch Class review: Pricing and availability

The Vizio M-Series Quantum X series comes in three sizes — a 50-inch (reviewed here), a 65-inch and a 75-inch model. Most specs carry over across the sizes, but it’s worth noting that there are some important differences between them that we’ll be pointing out throughout the review.

• M-Series QX 50-inch 4K Quantum Color Smart TV (M50QXM-K01): $629.99
• M-Series QX 65-inch 4K Quantum Color Smart TV (M65QXM-K03): $849.99
• M-Series QX 75-inch 4K Quantum Color Smart TV (M75QXM-K03): $1,199.99

In terms of a release date, the Vizio M-Series Quantum X became available starting in July 2022 for $629. That price is similar to what we’ve seen from other mid-range performance-focused TVs like the TCL 6-Series and the Samsung Q60A  that often sell for $699. We like the Vizio slightly less than the TCL 6-Series, but it does feel like a better TV than the Samsung Q60A that uses edge lighting instead of full array with local dimming.

Vizio M-Series Quantum X 50-inch Class review: Design

The Vizio M-Series Quantum X takes two steps forwards and one step back in the design department. It’s easy to love the incredibly thin bezel on the front of the TV and the solid metal strip along the bottom, but it’s a bit chunky compared to similarly sized TVs. 

At 26 pounds, it’s relatively light, but wall-mounting it higher than your shoulders is going to take a bit of effort given the bulkiness of the screen. Even then the TV will jut out over 3 inches from the wall, which is more than other QLED TVs. Its full measurements without a stand are 43.81 x 25.48 x 3.41 inches. Thankfully, the TV uses a standard 200mm x 200mm VESA mount so it should be compatible with most cheap mounts out there.

It’s a shame that this TV is so heavy for its size and bulky in the back. It’s going to look better on a shelf than on your wall, because from the front there’s nothing to complain about. 

The true saving grace for the TV’s design, however, is the integration of HDMI 2.1 ports with one that can hit 4K/120Hz gaming and up to 240Hz when paired with a PC. That said, the 240Hz mode is limited to the 50-inch model. If you choose something bigger, you’ll lose out there — but don’t worry, there are some benefits that we’ll cover in the next section. One port with 4K/120Hz support is better than none, but we wish there were more ports with that spec.

Vizio M-Series Quantum X 50-inch Class review: Performance

The design might be a bit of a letdown, but the performance is every bit of what we’d expect from a mid-range 4K HDR TV and then some. We tested the set using an X-Rite i1 Pro spectrophotometer, a SpectraCal VideoForge Pro pattern generator, and Portrait Displays’ Calman calibration software and encountered some strong results for a TV in this price range.

In Bright SDR mode, basically what you’d see out of the box if you didn’t change any of the other settings besides the picture mode, you’ll get around 500 nits of peak brightness. That’s perfect for your basic cable TV. Upscaling is decent thanks to Vizio’s IQ Ultra+ Processor and motion really wasn’t an issue. In terms of color coverage, we measured its Rec.709 Gamut Coverage at 99.9194% but a Delta-E — which measures how the source color differs from the displayed color (with lower numbers being better) — at a 9.09, which was a bit high.

Instead of watching in Bright mode, we tend to recommend the Calibrated mode instead. It’s darker and less colorful, unfortunately, but you’ll get more accurate colors. In Calibrated mode, we measured peak brightness at 428 nits, Rec.709 Gamut Coverage at 97.8749% but a much better Delta-E of 1.7444. Those numbers, for a mid-range TV, are terrific.

Our HDR test results, while still good in their own right, didn’t impress us as much.

In Bright mode with HDR content we measured a peak luminance of 495 nits in a 10% window. That’s around what you’d get with some older OLED TVs, but it’s not great for a QLED TV like this one. If you switch it to Calibrated mode where the color gamut coverage is better and more accurate, you’re looking at a peak brightness of only 426 nits. Considering a 55-inch Sony A80J OLED can hit over 700 nits, these numbers aren’t exactly wonderful.

Numbers are just numbers, however. In practice, shows and movies looked generally good on the M-Series Quantum X. It may not be in the top echelon with the likes of Samsung’s new QLED or the Sony QD-OLED, but it has a workman-like performance. Re-watching Game of Thrones in 4K Dolby Vision was nice and crisp, with great motion in Calibrated mode. The colors weren’t vivid and the shining city of King’s Landing wasn’t as bright as we believe they could have been, but the picture performance was consistently good.

Watching Lightyear on Disney Plus in Dolby Vision, the TV put out convincing black levels that were only occasionally marred by blooming when a bright object crossed an all dark background. Still, though the picture looked better than any TV under $700 had any right to be — minus the few issues we’ve already mentioned. 

Vizio M-Series Quantum X 50-inch Class review: Audio

The M-Series Quantum X’s audio isn’t anything to write home about — its two 10W speakers do create a wide soundstage, but they lack clarity when you use the DTS Virtual: X audio mode. Adversely, if you turn it off, you gain some clarity but lose the wide soundstage.

Sound effects, largely, aren’t impactful because of the limitations of the speakers. What that means is that, at some point, you’ll want to upgrade to a soundbar. 

The good news is that out-of-the-box sound is passable, especially mid-range dialogue, which can be heard especially well if you just disable the DTS Virtual:X sound.

Vizio M-Series Quantum X 50-inch Class review: Gaming

As far as gaming performance goes, the Vizio M-Series Quantum X performs as good or better than some of the best TVs this year. With 13.2ms of lag in game mode, the TV is well-under the 20ms we typically recommend for fast, responsive gameplay and with support for Dolby Vision, certain games in your collection are going to look brighter and more colorful than you’ve ever seen them.

Of course, why you’re really buying the M-Series Quantum X for is its HDMI 2.1 port that supports 4K/120Hz out of the box. We can confirm it works as advertised without any additional messing around with the settings. That said, we could only get it to work on HDMI 3 — thankfully a separate port from the eARC port in HDMI 1. 

If you have a gaming PC up to the task, you can even take things one step further by playing games at 1080p /240Hz. Without a powerful enough PC near to our TV testing station, we weren’t able to test it for this review, but we were able to watch some clips of this in action and the results — from what our ageing eyes could make out — looked even smoother.

No matter how neat 1080p/240Hz gameplay is, the issues that we talked about above with performance impact how games are going to look, obviously — i.e. capping the brightness at around 500 nits. It’s not a game-ruiner, especially at this price, but it’s a small drawback.

Vizio M-Series Quantum X 50-inch Class review: Smart features

As far as smart platforms are concerned, Vizio’s SmartCast is holding its own as one of the better — if not quite the best — smart TV platform. 

One of the reasons for that is because SmartCast has an interesting — and useful — layout. On the very top is a row of categories that include recommended movies and shows as well as free content (always with ads)  and Live TV provided by Vizio’s WatchFree+ service. Below that top row are the curated shows and movies, a recommended row of content and then, finally, a fixed number of apps in the center row that can be re-arranged depending on your preference. It’s clean and efficient.

The other unique aspect of SmartCast is its deep integration with Google’s Cast function that allows you to send content from your phone to the TV. Other TV manufacturers have some implementation of this, but Vizio TVs come with Chromecast Built-in essentially.

Big this year for SmartCast is the integration of Wi-Fi 6 into the TV for faster streaming with compatible routers, Bluetooth headphone support and a voice search remote with every TV in the lineup, all the way down to the value-focused D-Series. We’ll cover the remote down below, but the speed boost from a Wi-Fi 6 antenna won’t go unnoticed in your home.

In terms of app support, all the major players are here: Netflix, Hulu, Prime Video, Hulu, Apple TV, Disney Plus, HBO Max, Peacock, Sling TV and YouTube TV. The only problem with apps being pre-loaded onto the TV for you is that you don’t have a say what apps are installed versus not installed. It’s not a major detractor from SmartCast’s overall solid usability, however, you might notice a bit of lag when moving around the UI which could be a sign of potential issues down the road — but we’ll be watching this area closely.

Vizio M-Series Quantum X 50-inch Class review: Remote

The 2023 Vizio Voice Remote isn’t all that different from previous iterations. There are six shortcut buttons near the top that give you direct access to the most popular streaming services as well as a circular directional pad and volume controls. 

If you press and hold the microphone button on the remote, you’ll activate SmartCast’s built-in assistant that can help you find a show or movie. It’s not as smart as the mainstream smart assistants from Google or Amazon — it can’t answer questions like ‘what time is it?’, for example — but it does a good job of searching across all services.

There’s not really as much innovation happening with Vizio’s remotes as, say, Samsung’s that can now charge off of both sunlight and RF energy from your Wi-Fi router, but Vizio’s clicker at least nails the basics.

Vizio M-Series Quantum X 50-inch Class review: Verdict

For gamers, the Vizio M-Series Quantum X at a 50-inch size is going to be incredibly tempting, but it falls short of universal appeal for the most ardent of AV enthusiasts. Its HDR test results, while good, aren’t mind-boggling and have some real soft spots. The good news is that movies and shows still look nice on the Quantum X.

There’s a fundamental difference in light output between the 50-inch version we reviewed here and the larger 65- and 75-inch variations, so don’t let this review put you off from those — however, we ultimately found that the Vizio M-Series Quantum X brings the best of Vizio’s top-performing TV to a budget price point … with a few compromises.