A Review of the LG UM6900 4K HDR LCD TV (43UM6900, 49UM6900, 55UM6900, 65UM6900)
Stephan Jukic – January 20, 2020
The LG UM6900 is one of the brand’s most affordable and economical 4K UHD TVs of 2019 and 2020. That said, it’s a fairly decent television that has several useful specs to offer for a rock bottom price that includes performance which is pretty good for an entry level ultra HD TV. The UM6900 is especially good for use as a gaming TV and as an extra studio, bedroom or dorm television, its price makes it pretty enticing.
One extremely notable thing about this 4K TV is that it comes with LG’s RGBW display pixel technology, which offers what is only debatably called true 4K UHD resolution of the kind that’s normally found in 4K TVs. Among the major brands, only LG’s ultra-budget UHD TVs come with this, and while the total number of pixels is the same, the white subpixel definitely weakens certain aspects of display performance because only one out of four pixels comes with full, normal RGB subpixels.
• Very Low input lag & response time for gaming performance
• Excellent IPS viewing angles
• Great color accuracy and 10-bit HDR color
• Great smart TV platform
• LG’s pseudo-4K RGBW white subpixel setup
• Crappy contrast and black uniformity/level (because of IPS display)
• Weak SDR brightness
• Really weak HDR performance
• Native Audio is really bad
For an ultra-budget 4K UHD TV with very basic HDR and RGBW alternating white sub-pixel display, the UM6900 actually performs fairly decently for most casual movie, TV or gaming needs. Considering its price and numerous size options, we recommend it as an extremely affordable starter or extra bedroom TV. For use in your main home theater system, we’d suggest something a bit better though.
Our comprehensive review of the best IPS TV we’ve ever reviewed, LG’s powerful new SM9000 4K HDR edition
What We Liked about the UM6900
Despite some major issues with its performance that we’re going to cover shortly, the LG UM6900 is actually pretty decent overall as a very basic, cheap budget ultra HD TV. It delivers the essentials and even handles some of them very well. As a basic 4K HDR gaming TV, it’s particularly recommendable. Other strong, likeable aspects of this television’s performance include the following:
Gaming connectivity & performance
The gaming chops of the UM6900 are a bit variable because this TV doesn’t support any resolution at more than the 60Hz that correspond to its native display refresh rate. This means no playing games via console or PC at above 60fps. However if you keep this limitation in mind, the UM6900 is one excellent performer in terms of low input lag for gaming at all lower frame rates. It also delivers its low input lag in assorted resolutions, color settings and with HDR on or off. An additional benefit of this TV is its extremely fast pixel response time, which helps keep motion blur nicely low as pixels rapidly shift colors on the screen. This too helps keep gaming smooth and crisp.
Great viewing angles
IPS TVs like the UM6900 come with a display technology whose pixels are aligned more horizontally instead of vertically. The opposite, called VA (vertical alignment) is more common in today’s LCD 4K HDR TVs and while the VA variant means much stronger contrast ratios and black levels/uniformity, the UM6900’s IPS screen does offer far better viewing angles. Your average VA TV rapidly loses color and contrast quality when viewed from even a bit off from dead center. The IPS screen of the UM6900 doesn’t have this problem, which is useful if you have a widely arranged viewing space in a squashed room.
Very decent color support on key specs
As we’ll cover shortly, the UM6900 isn’t actually a particularly great HDR TV. It lacks too many of the key specs for really strong HDR rendering in the right kind of content. However, what this TV does offer is generally strong color performance. On the one hand, the UM6900 delivers this in the form of excellent color accuracy for both SDR and HDR content, after the TV has been calibrated a bit via its picture settings menu controls. Secondly, the UM6900 delivers the HDR color spec of 10-bit color really nicely, with mostly smooth gradation between 1.07 billion different values of the red green and blue subpixels that work to create all other visible colors on this TV’s screen.
In basic terms, for both SDR and HDR content, the UM6900 will deliver reasonably vibrant and exceptionally accurate color rendering unless the content it’s displaying was badly mastered.
LG’s superb smart TV platform
The LG WebOS smart TV platform is one of our favorite native smart TV interfaces to-date. We have always liked it because of its extremely smooth functionality, highly intuitive user interface and usability for accessing content from potentially hundreds of different media apps. The version installed in the UM6900 is WebOS 4.5 and it’s the best we’ve seen yet. Unfortunately, the UM6900’s remote doesn’t come with smart features like voice control, but the smart platform itself is the same as it is in any of this brand’s priciest 4K HDR TVs.
Our comprehensive review of the best IPS TV we’ve ever reviewed, LG’s powerful new SM9000 4K HDR edition
What We Didn’t Like
Despite its saving graces as a budget ultra HD TV, the UM6900 edition comes with plenty of flaws. A couple of them are very serious and the UM6900’s RGBW issue is our biggest peeve of all. On the other hand, we don’t think any of the defects we’re about to cover necessarily make this TV a total loss when you consider its low price and generally decent performance for most content.
the RGBW alternating white sub-pixel design
First and worst of all among the LG UM6900’s flaws is this 4K TV’s RGBW display design with alternating white subpixel. Now, RGBW basically means that for every normal three subpixels for red, green and blue respectively (RGB) inside any given full pixel, an additional white subpixel is included. This by itself isn’t a problem in 4K TVs and some of LG and Sony’s absolute priciest OLED TVs come with exactly this same technology. However, in the case of these pricier editions, the RGBW always includes red, green and blue along with the additional white in each full pixel.
The difference in LG RGBW budget TVs like the UM6900 is that instead of a complete set of RGB subpixels next to each white subpixel within each full pixel, what you get instead are two of these colors then white per pixel until it rotates back, like this: RGB, WRG, BWR, and GBW, then RGB again and repeat. Thus, only one out of every four full pixels comes with RGB colors. What that means is a lot of extra white light taking the place of the full RGB array.
Surprisingly, the effect isn’t as noticeable as you might think while you’re watching most regular content on the UM6900, but what it does do is weaken overall contrast and black level performance even more than the IPS display already does with its innate backlight bleed-through, and thus the RGBW can sometimes screw with how richly colors render for certain types of content. This pixel setup is also arguably not full 4K resolution since white subpixels take up the equivalent of a full quarter of all 8.29 million pixels on the screen, even if they’re blended deeply in.
Very weak SDR display brightness
In addition to its weak contrast, weak black levels and the above-mentioned RGBW design screwing with the UM6900’s display performance, this 4K TV also delivers only mediocre peak brightness when used for regular content outside of HDR mode. The UM6900’s HDR luminosity isn’t exceptional at all either but it’s at least decent. The SDR brightness for regular content on the other hand is just disappointing. It never even reaches above 200 nits.
General HDR performance
All of the details above combine to do one major thing in the UM6900, which is ensuring that this is definitely not a great 4K TV for HDR content. Since the UM6900 doesn’t support wide color gamut for full HDR color, doesn’t deliver deep black levels and contrast for HDR shadows and doesn’t get very bright for strong HDR highlights, the overall result is a 4K HDR TV that barely manages a minimum of visible HDR support. What little it does pull off is in the form of strong color accuracy and smooth 10-bit color variation for high dynamic range movies, games and streaming content.
Crappy native audio
To finish off our section of negative aspects of the UM6900, we come down to its native audio support, which is basically crap. This 4K TVs internal speakers are okay for casual news or background TV audio but if you want any kick at all for movies, games or music, you’ll definitely need an external sound system.
Value for Price & Bottom Line
The LG UM6900 4K HDR TV isn’t bad despite all its flaws, because when you actually watch high quality content and TV programming on it, it still looks very good, and this TV delivers motion handling very decently as well. However, unless you need a very cheap IPS TV in particular, there are better options available for similar prices. We particularly recommend Samsung or TCL 4K TVs in the budget range as alternatives.
Key LG UM6900 Specs
• Screen sizes: 43 inch 43UM6900, 49 inch 49UM6900, 50 inch 50UM6900 55 inch 55UM6900, 60 inch 60UM6900, 65 inch 65UM6900, 70 inch 70UM6900, 75 inch 75UM6900 (TV being reviewed is 50 inches)
• Smart TV: WebOS 4.5 2019 Edition
• HEVC (H.265) Included: Yes
• VP9 Included. Yes
• HD to UHD to 4K upscaling: Yes
• HDCP 2.2 Compliance: Yes
• HDR Support: Yes, HDR10, Hybrid Log Gamma
• Refresh Rate: 60Hz refresh rate
• Screen Lighting: IPS LCD Display with edge-lit backlighting, no local dimming
• Resolution: 3840 × 2160 pixels 4K UHD
• Wireless Connectivity: Yes, includes both built-in WiFi and Ethernet port
• Remotes: LG button remote
• Connectivity: 3 HDMI ports (all of them 2.0a and with HDCP 2.2, 2 USB ports, 1 Ethernet port, 1 Digital Audio Out
• Contrast Ratio: 978:1 (native, real maximum contrast)
• Absolute Maximum Peak Brightness: 333 nits (cd/m2)
• 3D Technology: N/A
Display Performance Metrics
In the sections bellows, we cover the specs that matter most for judging how well the LG UM6900 4K HDR LCD TV delivers on quality home theater handling. The following metrics detail the key specs of brightness, color, motion handling, and other crucial things that really matter. They are in fact what matters most for movies, TV shows, broadcast content, gaming and even hookup of the TV as a PC monitor if you prefer. We cut out all the fluff and marketing jargon that doesn’t really explain genuine quality anyhow.
We’ve based the following measurements and conclusions on the specific model being reviewed, but their accuracy is exact enough to reflect what they should be like for any normally functioning editions of the LG UM6900. Slight variations for some of the specs in the sections below might be the case from unit to unit and with editions of different sizes.
Black Level, uniformity, Local Dimming and Contrast:
As we already mentioned above, the UM6900 is an IPS 4K TV with the added weakness of RGBW pixel design in which three out of every four pixels replaces one of its RGB subpixels with a white subpixel. The overall result of this combination is a level of black level performance and contrast that’s nearly abysmal. The UM6900 just doesn’t deliver any kind of strong, rich black depth, and its black uniformity is pretty lackluster. As a result, the peak contrast ratio of this 4K TV is also really low even by IPS 4K TV standards. It tops out at no more than 978:1. All other LG LCD 4K TVs with IPS display do a fair bit better than this.
As a result of the above, the UM6900’s HDR and SDR video quality is only okay. The tradeoff here is that the IPS display does deliver great viewing angles but other IPS TVs do the same with better contrast. The UM6900 also isn’t helped by its lack of local dimming. This technology -which selectively dims LEDs behind the screen for better dark levels- would have gone a long way towards making an IPS TV like the UM6900 deliver much better picture performance.
The UM6900’s peak and sustained brightness is mediocre when not turned to full HDR mode and even when set to HDR, it performs only modestly well. For qualities like these, LG’s own SM7300 IPS TV gets noticeably brighter even though it costs a bit more. The modest brightness of the UM6900 is also slightly hampered by its weak black levels and contrast, which make its bright highlights stand out less than they could.
LG UM6900 SDR Brightness
- Overall SDR peak brightness for normal content: 165 nits
- Peak 2% display area display SDR brightness: 189 nits
- Peak 10% display area SDR brightness: 192 nits
- Peak 100% display area SDR brightness: 189 nits
- Sustained 10% SDR brightness: 190 nits
- Sustained 100% SDR brightness: 193 nits
LG UM6900 TV HDR Brightness
- Overall HDR peak brightness for normal content: 289 nits
- Peak 2% display area display HDR brightness: 319 nits
- Peak 10% display area HDR brightness: 333 nits
- Peak 100% display area HDR brightness: 322 nits
- Sustained 10% HDR brightness: 321 nits
- Sustained 100% HDR brightness: 322 nits
The LG UM6900’s color performance is surprisingly good despite its RGBW display technology and weak black levels (both can mess with perceived color quality.) This TV doesn’t offer wide color gamut but it can handle 10-bit color rendering quite nicely. Furthermore, after a bit of calibration, the UM6900 offers superbly good color accuracy once it’s been calibrated in the picture settings options out of the box. That said, color quality in the UM6900 does deteriorate when the TV plays back very bright or very dark scenes.
In general, the important thing to note about the UM6900 is that it will output mostly rich colors that look realistic when it’s used to play both ordinary TV content and more dynamic HDR video sources. For users who’ve never before owned an HDR 4K TV, the perceived picture quality won’t look bad at all. The color vibrancy of the UM6900 is spoiled a bit by the IPS display and RGBW pixels of this TV but if the effect isn’t as bad as we expected. Furthermore, because of its IPS display, the UM6900 delivers excellent color saturation even when viewed from way off dead center. Typical LCD TVs with VA display can’t manage this.
Here are the UM6900’s key color delivery specs:
- Pre-calibration White Balance delta-E: 4.91
- Pre-calibration Color delta-E: 3.70
- Pre-calibration Gamma: 2.25
- Post-calibration White Balance delta-E: 0.35
- Post-calibration Color delta-E: 1.82
- Post-calibration Gamma: 2.12
- Wide Color Gamut: 82.8%
Motion Handling & Upscaling:
LG’s UM6900 offers good but not exceptional motion handling. Combined with this TV’s excellent gaming chops for low input lag, it works nicely for most uses but can’t deliver content at above 60fps, even with motion interpolation, which is only moderately good in this TV. That said, this model does a very decent job at motion blur control due to its great pixel response time, which is fast at 5.1 milliseconds. This measures how quickly pixels change color as content shifts across the screen. This of course also means low motion blur for movies, TV viewing or sportscasts.
As for judder control with 24p content, the UM6900 can handle judder-free content delivery from disc media, broadcast, streaming and HDMI sources without a problem. On the other hand, it doesn’t offer this for movies from external 60Hz devices like cable boxes.
We should also note that the UM6900 comes with no variable refresh rate technologies like AMD FreeSync or NVIDIA G-Sync. Most casual gamers won’t have a problem with this though.
In terms of content upscaling for video sources that are playing on the TV at resolutions below its native 4K ultra HD, like virtually all modern 4K UHD TVs, the UM6900 offers excellent sharpening of any well-mastered content from just about any source. 1080p video sources look wonderfully sharp on this edition and even 720p and 480p video is rendered sharply. This is of course very important simply because most of the content available from any and all sources today isn’t natively 4K ultra HD. The interesting thing here is that the UM6900 pulls off its strong upscaling despite its RGBW pixel structure, which reduces the number of full red, green and blue subpixels by a quarter.
Input Performance for Gaming and PC:
One of the things that the LG UM6900 truly excels at is how well it handles gaming input lag within the limits of its 60Hz display refresh rate. When set to game mode, this TV can really keep input lag down for console games in both 40 and 1080p, with HDR or without and at different color settings. One flaw is the lack of frame rate smoothing technology like FreeSync or G-Sync but unless you’re very serious about gaming, this isn’t a huge problem. Because the UM6900 lacks a native 120Hz refresh rate on its screen, it can’t deliver gaming refresh rates of more than 60Hz in any resolution, so this is worth remembering. It also doesn’t support 1440p resolution for some reason.
Here are the UM6900’s important input and PC connectivity specs:
- 4k @ 60Hz: 10.9 ms
- 1080p @ 60Hz: 10.2 ms
- 1080p @ 120Hz: N/A
- 1080p @ 60Hz outside Game Mode: 101 ms
- 4k @ 60Hz + HDR: 12.5 ms
- 1440p @ 60Hz: N/A
- 4k @ 60Hz Outside Game Mode : 110.2 ms
- 4k @ 60Hz @ 4:4:4: 9.5 ms
- 4K @ 120Hz: N/A
- 1440p @ 120Hz: N/A ms
- 1080p with FreeSync: N/A
- 4K with interpolation activated: 108.7 ms
PC Gaming Input Connectivity
- 1080p @ 120Hz: No
- 1080p @ 60Hz @ 4:4:4: Yes
- 4k @ 60Hz + 4:4:4: Yes
- 1440p @ 60Hz: Yes
- 4k @ 120Hz : No
- 4k @ 60Hz @ 4:4:4: Yes
- 1440p @ 120Hz: No
The LG UM6900 basically includes the full scope of up to date connectivity specs for any normal consumer 4K, HDR and other digital, cable or broadcast content. The only problem with this TV is that it comes with only 3 HDMI ports with 4K capability at 60Hz (HDMI 2.0a) and offers 2 USB ports instead of the more typical 3. There’s also full high speed WiFi connectivity and an Ethernet port.
The following are the LG UM6900’s ports and their specifications:
- HDMI : 3 (HDCP 2.2 & full HDMI 2.0a capacity)
- HDMI 2.1 : N/A
- USB : 2 (USB 2.0 x 2)
- Digital Optical Audio Out : 1
- Analog Audio Out 3.5 mm : 1
- Tuner (Cable/Ant) : 1
- Ethernet : 1
- HDR10 support: Yes
- HDR10+ support: No
- Dolby Vision HDR support: No
- Hybrid Log Gamma HDR support: Yes
The LG UM6900 TV models also offer audio connectivity in the following types.
- 1 Passthrough ARC Dolby Digital
- 1 Passthrough Dolby Digital via ARC
- 1 Passthrough Optical Dolby Digital
- 1 Passthrough DTS via Optical
- 1 Passthrough ARC
LG is selling the UM6900 4K ultra HD HDR LCD Smart TV models in numerous different sizes. Thus, you have an exceptional range of choices with this TV. Available units come in: 43, 49, 50, 55, 60, 65, 70 and 75 inch size ranges. All of them are highly affordable for their
These editions all sell for the following prices, found in the link below at the time of this writing. Bear in mind that these are subject to sometimes frequent downward change and it’s a good idea to click the following Amazon links for real-time pricing and all available discounts on this model.