The Vizio P Series Quantum X is an excellent 4k LED LCD TV. It delivers great overall picture quality with deep, uniform blacks, outstanding peak brightness, and a great local dimming feature. Motion looks great, thanks to the outstanding response time. It also has excellent low input lag, ensuring a responsive gaming experience, although it doesn't support any of the advanced gaming features, like FreeSync, found on some other TVs. Unfortunately, the image degrades when viewed at an angle, and there is noticeable banding in areas of similar color.
The Vizio P Series Quantum X has a great design, and is identical to last year's Vizio P Series Quantum. The stand has a nice metal finish and supports the TV well, but the two feet are nearly the full width of the TV, so you'll need a wide stand if you aren't VESA mounting it. This TV, like last year's, has very good build quality, with no obvious points of concern.
The stand is slim but well-built, and it supports the TV well. Unfortunately, the feet are very wide and can't be reversed, so you'll need a very wide table if you aren't wall-mounting it.
Footprint of the 65" stand: 50.8" x 11.7".
The back of the TV is plain, made up of a single textured plastic panel. The inputs face down and to the side, and they are easy to access when the TV is VESA mounted.
Unfortunately, there is no cable management.
The borders are thin and aren't distracting at all when watching TV.
The TV is relatively thin and doesn't stand out very much when viewed edge-on. It looks great when wall-mounted, but isn't as thin as OLED TVs like the LG C9.
This image was taken with a different camera, as our FLIR E8 is currently out for repair. We don't expect this to affect our results.
The P Series Quantum X appears to be well-built, with no obvious deficiencies or weak points.
The Vizio P Series Quantum X delivers great overall picture quality. It has an outstanding native contrast ratio, and the local dimming feature is great. Like last year's model, this is one of the brightest TVs on the market, and it has the widest Rec. 2020 color gamut we've measured so far. It has great black uniformity, excellent reflection handling, and decent gray uniformity. Unfortunately, like the majority of VA TVs, the image degrades when viewed at an angle. It also has worse-than-average gradient handling, which results in noticeable banding in some content.
The full array local dimming feature is extremely effective at dimming dark areas on the screen and is one of the best we've ever seen. It reacts quickly to fast scene changes, but can't always keep up, and it tends to dim the outside edges of bright, fast-moving objects, which can be noticeable in some scenes.
There is noticeably less blooming around bright objects than last year's model. There can still be some noticeable blooming around subtitles in dark scenes though, as well as around very bright objects in dark scenes, but it's better than previous models.
If you enjoy local dimming and don't mind some variation in screen brightness or blooming, then set local dimming to 'Medium'. This does increase the overall brightness of the image though, and can result in distracting blooming around bright objects. If you prefer a less aggressive local dimming implementation or find the brightness too high after decreasing the 'Backlight' then set it to 'Low', or disable local dimming completely if you don't like the changes in brightness.
The setting that controls the backlight is known as Active Full Array. During testing, we discovered that adjusting this setting sometimes caused the Black Frame Insertion feature to be disabled.
Note: The 75" model has more dimming zones, and we expect the local dimming feature to perform slightly better.
Update 07/16/2019: Text updated to clarify settings.
We measured the peak brightness after calibration, with the 'Calibrated Dark' Picture Mode, Local Dimming set to 'Medium', and the Color Temperature set to 'Normal'.
If you prefer a brighter image, or a colder color temperature over an accurate one, with the 'Standard' Picture Mode we measured a peak brightness of 2922 cd/m² for a short period of time, as measured on the 10% test window.
By design, the TV dims when it detects a static pattern, including our test patterns. Vizio sent us instructions on how to work around this, but we were still unable to get consistent results, as the TV's brightness is very finicky.
This TV can get extremely bright in HDR. Small highlights in some scenes are extremely bright, which is great. Even large, bright scenes are very bright, although not quite as bright as last year's model.
We tested the HDR peak brightness with no calibration settings, using the 'Calibrated Dark' Picture Mode, with the Backlight set to '50', and local dimming set to 'Medium'.
If accuracy isn't as important to you, or if you prefer a colder color temperature, the 'Standard' Picture Mode hit a peak brightness of 2741 cd/m² for a short period of time, with the Color Temperature set to 'cool', and local dimming on 'High'.
By design, this TV dims the screen when it detects static images, like our test patterns. Vizio sent us instructions on how to work around this, but we still weren't able to get consistent results.
Decent gray uniformity, but the sides of the screen are noticeably darker. There is also noticeable dirty screen effect (DSE) in the center of the screen, which isn't great for watching sports. In near-dark scenes, the uniformity is much better, with no significant issues.
The P Series Quantum X has a poor viewing angle. Moving off-center, the image loses brightness, and the black level increases, causing the image to appear washed-out. At even moderate angles colors lose accuracy and appear washed-out.
Like the Vizio P Series Quantum, this TV has an optional 'Enhanced Viewing Angle' feature, which is intended to improve viewing angle performance. We measured both and found no advantage for enabling this feature. When it is enabled, it changes the TV's sub-pixel dimming, which reduces the overall color resolution and causes some noticeable issues.
During testing, when changing inputs the Enhanced Viewing Angle function would engage itself automatically, but the setting still shows 'Off'. To disable it, we had to turn it on, then off again.
Great black uniformity, which is great for dark-room viewing. With local dimming disabled, there is some very slight clouding visible. Once local dimming is enabled, though, the black uniformity is significantly better, and there is no noticeable clouding around the white test cross.
Excellent reflection handling, very similar to last year's P Series Quantum. Unlike many high-end TVs, there is no purplish tint from the anti-reflective layer.
With our pre-calibration settings, this TV has decent accuracy. There are some noticeable color inaccuracies, and there are noticeable inaccuracies in brighter shades of gray. The average gamma is close to the calibration target of 2.2, but some scenes are over-brightened, and some are too dark.
This TV has a full white balance and color calibration system, and after calibration, it has outstanding accuracy. Color and white balance accuracy are both significantly improved, and any remaining inaccuracies aren't noticeable. The color temperature is close to our target of 6500K, and gamma follows the target almost perfectly.
You can see our recommended settings here.
Like all other Vizio TVs we've tested, 480p content, like DVDs, is upscaled decently but appears a bit more blocky than other TVs.
720p content, like from a cable box, looks decent, but like other Vizio TVs we've tested, the image is a bit worse than most other TVs.
1080p content, like Blu-ray movies or older game consoles, looks almost as good as native 4k content.
4k content looks great. When the TV's Enhanced Viewing Angle feature is enabled, the TV uses spatial dithering, which can cause issues with some content, as shown by the shadows in this image.
This TV also always applies an edge enhancement, even when Sharpness is set to '0'. This results in some noticeable issues, as seen here.
The P Series Quantum X has an outstanding color gamut, one of the best we've ever measured. It covers almost the entire DCI-P3 color space, and has the best Rec. 2020 coverage of any TV we've tested so far.
Some dark scenes appear too dark, but otherwise this TV follows the PQ EOTF curve well, before tone-mapping near the TV's peak brightness. In 'Game' mode, the EOTF is identical.
This TV has great color volume. It can display dark saturated colors, and bright colors are close to the TV's peak brightness.
Update 08/19/2019: We updated the firmware to version 126.96.36.199-1 and retested the gradients. There is slightly less banding in all colors, but not enough to make a noticeable difference.
Decent gradient handling, but there is mild banding in almost all shades, and there is more significant banding in dark greens and grays. Unfortunately, the Reduce Noise feature does not appear to improve gradients at all.
There is no noticeable image retention on the PX65-G1, even immediately after displaying our high-contrast test image for 10 minutes.
We don't expect VA panels to experience permanent image retention, as the VA panel in our long-term test appears immune.
When the enhanced viewing angle feature is enabled, some subpixels are partially dimmed, as shown here.
The P Series Quantum X 2019 has very good motion handling. It has an excellent response time, but there is some ghosting in some scenes. It also has an optional black frame insertion feature, which can help to improve motion clarity, but we had some issues getting it to work properly. Unfortunately, this model also uses PWM to dim the backlight; this flicker can cause duplications in motion and can bother some people.
The Vizio PX65-G1 has an excellent response time, very similar to last year's model. There is some overshoot in some transitions, which can cause some inverse ghosting, but this shouldn't be that noticeable. There are noticeable duplications in our response time photo due to the backlight flicker.
Unfortunately, this TV uses PWM to dim the backlight, and there is a 120Hz flicker at all backlight levels other than max. This results in duplications in motion, which might be noticeable in certain content.
Although we initially measured a 960Hz flicker on the Vizio P Series 2018 and Vizio P Series Quantum, which is much less noticeable, we have retested them and found that they also flicker at 120Hz now. We don't know when this change occurred, but it was likely in one of the firmware updates over the past year.
For even clearer motion, this TV has an optional black frame insertion(BFI) feature, which reduces the backlight flicker frequency to 60Hz. There was a bug during testing, where adjusting the local dimming feature to a higher setting disabled this feature.
We found the BFI feature to behave very erratically. When enabling this feature, we found that it wouldn't always start flickering at the right time, which resulted in strobe crosstalk duplications. It appears to be random, but enabling Game Low Latency appears to be more likely to get a perfect image.
When BFI is enabled, a compensation algorithm is engaged to try and compensate for the normally reduced brightness. This is why the image appears so different from our usual BFI photos.
The Vizio P Series Quantum X has a 120Hz panel and can interpolate lower frame rate content up to that refresh rate. Like last year's model, the motion interpolation feature is very aggressive, and there are noticeable artifacts in busy scenes.
Learn more about the motion interpolation feature, and how to adjust it, here.
Due to the fast response time, there is some noticeable stutter, especially when watching 24p content like movies. This is especially noticeable with slow, panning shots. If stutter bothers you, the motion interpolation feature can help, by increasing the frame rate of your content.
The Vizio P Series Quantum X can remove judder from any 24p source, including from the native apps, but it can't remove judder from 60 i/p sources, like a cable box. For 24p sources, no special settings are required; the TV always plays them without judder.
The P Series Quantum X 2019 has a 120Hz refresh rate, but it doesn't support any variable refresh rate technologies, like FreeSync or HDMI Forum's VRR feature.
The P Series Quantum X has excellent low input lag, especially when connected to HDMI port 5, which is a dedicated low latency port. It supports most of the common formats but does not support 1440p, which may disappoint some gamers. Like the 2018 Vizio TVs, this one has a built-in TV tuner, which is great for cord-cutters.
The Vizio P Series Quantum X has excellent low input lag. Unlike most other TVs, the low latency mode can be applied to any picture mode, simply by enabling the Low Latency setting.
This TV, like previous Vizio TVs, has a low latency port (HDMI Port 5). This port delivers the lowest input lag possible, but does not support HDR.
We also measured the input lag on HDMI port 1:
|Test||HDMI 1||HDMI 5|
|1080p @ 60 Hz||25.6||14.7|
|Out of Game Mode||136.8||89.7|
|1080p @ 120 Hz||29.6||10.5|
|4k @ 60 Hz||26.0||16.6|
|Out of Game Mode||151.1||83.1|
This TV does not support auto low latency mode (ALLM).
The P Series Quantum X supports most common input formats but does not support 1440p. All supported formats can display proper 4:4:4, as long as the Picture Mode is set to 'Computer'. This is especially important when using it as a PC monitor. Some formats require the full bandwidth of HDMI 2.0, and the Full UHD Color setting has to be enabled for the port used.
HDMI port 5 is a low-latency port, and it does not support some formats. HDR is not supported, and although 4k @ 60Hz is supported, it only works at 4:2:0.
HDMI port 5 is a low bandwidth port designed for low input lag, but it does not support some formats, including HDR and 4:4:4.
The P Series Quantum X does not support eARC.
To output DTS over the optical connection, we had to manually set the audio to 'Bitstream'.
The Vizio P Series Quantum X that we tested has disappointing sound, but something might be wrong with our unit, so your experience may vary. Our unit can't get very loud and has very little bass, with no thump or rumble and very little punch. It delivers clear dialog, though, and there is very little distortion, which is great. Per our out of spec policy, it's up to the manufacturer to decide if this warrants buying a new unit. If you bought this TV, let us know how it sounds in the discussions below.
The frequency response of our unit is bad, but something might be wrong with our unit, so your experience may vary. For reference, last year's P Series Quantum frequency response was average.
Low-frequency extension (LFE) is very high, and this TV has very little bass, with no thump or rumble and very little punch, but it produces well-balanced and clear dialog. Our unit can't get very loud, though, and is not suited for loud environments.
Note that there is an error in our graph due to a bug, which scales the green line up to 80dB. This line should be at the same place as the red and blue lines.
As our unit can't get very loud, there is very little distortion, which is great. Total distortion at 80 and at Max were both measured at the TV's maximum volume of about 70 dB SPL.
The Vizio P Series Quantum X 2019 has decent, but very basic, smart features. The interface is very intuitive and has a great design, but it's unfortunately quite slow and not very smooth. There are a few built-in apps, but unfortunately, like most Vizio TVs, there is no way to add additional apps. The included remote is the same basic remote found on lower-end Vizio TVs.
The interface is very easy to use, as it isn't very complex, but it isn't smooth and we found it to be quite laggy. Many simple tasks take longer than on most current TVs.