With the 48 “CX from LG, there is finally a smaller size OLED television for sale. It performs very well, but is still very expensive for the time being. The image quality is excellent and the operation is, thanks to webOS and the Magic Remote, very pleasant. Low input lag and support for variable frame rates make it the ideal TV for gamers.
LG CX 48 OLED TV Pros:
- Very good contrast
- Very accurate representation
- Good viewing angles
- Good sound
- Low input stroke
LG CX 48 OLED TV Cons:
- Too expensive for the size
- Short power cord
- No DTS sound
LG CX 48 OLED TV Review
All OLED panels for televisions that you can buy nowadays come from LG. Although Sony already put an 11 model on the market in 2008 and Samsung also briefly sold an OLED TV, only LG has succeeded in making OLED panels for televisions a commercial success. LG owes this success to patents. for white oleds that took over from the then ailing Kodak in 2009. In 2012, the once powerful photography giant went bankrupt due to the transition from analogue to digital photography, despite the company being at the basis of today’s highly successful digital technologies such as OLED and camera sensors.
LG OLED screens, based on white OLED with color filters, were introduced in 2013 with a 55 “screen size. Over time, sizes 65”, 77 “and 88” have been added. LG has opted to initially only make large sizes, because there is more margin on that. The investment in development and the construction of factories naturally had to be recouped. Over time, production costs have been drastically reduced by the construction of ever-larger factories. And now, after years of waiting, a 48 “model is finally available.
As of this year, the CX, the successor to the popular C9, will be available in the new 48 “size that we are testing in this review. In addition, the CX is also available in the familiar 55”, 65 “and 77” image sizes. The 4k uhd panel in the CX is powered by the third generation of LG’s ‘α9 Intelligent Processor’. Of course there is smart TV in the form of WebOS and you get a Magic Remote. At the time of writing, the 48 “version of the CX we tested was priced at around 1,700 euros in the Pricewatch. Remarkably, the 55” version was about 100 euros cheaper.
Appearance and connections
LG has not put too much effort into the design of the CX, it is almost the same as that of last year’s C9. We don’t find that a problem, because the CX still looks very sleek. Around the OLED panel is a thin, black finished metal decorative edge and the back is made of brushed metal. As with more OLED models, the TV is only a few millimeters thick at the top, but because the cabinet is four centimeters thicker at the bottom, you cannot hang the TV very close to a wall. At the center of the screen is a small bulge that houses the infrared receiver and an LED indicator.
The lower part of the housing on the back, which houses the speakers and electronics, is made of black plastic. It has a horizontal line structure, which makes it reminiscent of brushed metal from a distance. The glass plate in front of the image panel occupies the entire front, but the active image does not extend all the way to the edge, which means that when the TV is on, there is a narrow black border around the screen. This edge is a few millimeters wider at the bottom, because that is where the connections of the OLED panel are located.
Most of the base is on the back of the TV; it protrudes only a few centimeters at the front. The visible part of the base is one meter wide and made entirely of brushed metal. To prevent the TV from falling forward too quickly, LG has placed a substantial counterweight at the back. As a result, the CX cannot be placed too close to a wall on a piece of furniture. What is handy is the gutter integrated in the base, which keeps cables neatly out of sight.
Unfortunately, the power cord is still not detachable. Moreover, with a length of one and a half meters it is quite a bit on the short side. That is very inconvenient if you want to mount the TV on the wall, but also if you place it on a piece of furniture and use the cable duct in the base, the cord is very short. You then only have a few meters left to reach an outlet. So we would much rather have seen a detachable cord.
The connections are not all handy if you want to hang the TV. Some connections are placed straight back, making them difficult to reach. Especially the 3.5 mm headphone jack, which can also serve as an analog audio output, is in an awkward place. In the same place are also the optical, digital toslink and audio output, the network connection, the antenna connection, the f-connector for satellite reception, one of the four HDMI 2.1 connections and two of the three USB connectors.
On the side where the headphone jack should have been, these ports are located: the top of the CI + slot and below three of the four HDMI 2.1 ports, of which two input supports an audio return channel has. This is the most recent version known as eARC which has more bandwidth, supporting all recent audio formats. At the very bottom is the third USB connection. Thanks to support for WiSA, speakers can also be connected wirelessly.
WebOS and remote control
All LG televisions, except the cheapest models, run on webOS. In our opinion, this smart TV platform is one of the better. It is smart, responds quickly to commands and works very intuitively. The current version bears the name webOS ThinQ AI, because LG marketers have also discovered AI as the key to success.
Since last year there are two rows of large icons on the home screen. The extra row of shortcuts, which is above the oblique ’tiles’ with applications in the picture, adjusts automatically. For example, recommendations for Netflix and YouTube appear here, and you also get to see recently watched TV channels. The tile at the bottom left is used to show advertisements. Fortunately, you can turn off ads by turning off the Home promotion option in the menu under General.
The range of apps is not nearly as wide as Google’s Android TV, but as far as we are concerned, you won’t miss much, because the most important video on demand services are all available. The interface still looks fine, but we think the design could do with a makeover after all these years. We have seen small improvements over the years, making webOS a very mature smart platform, but would appreciate it if the design was thoroughly overhauled, as has happened with the operating systems on smartphones.
The design of the included remote control has also been around for quite some time. This also means that it is a very mature design that is not much to criticize. The main complaint we have, and that actually applies to remotes in general, is that more and more sponsored buttons appear on them. There are now three such striking buttons that are only useful for those who have a subscription to all these services. Even if you are a member of all those services, the buttons are redundant, because under the number buttons you have a quick access function that you can point to your favorite apps.
That said, the Magic Remote is still one of the best remotes in our opinion. It lies comfortably in the hand, the button feel is fine and the motion detection works very intuitively. You can also operate a set-top box with it and the built-in microphone works great for voice commands.
Input lag and chroma subsampling
Gamers looking for a new television to play on should choose one with a low input lag. Because images that come in via an HDMI input are buffered and processed before they actually appear on the screen, they incur a delay on what is called an input lag. In movie mode, the CX takes about 80ms to display the game images that are sent to the TV at 60fps. That equates to almost a five-frame delay.
Input lagHowever, the CX is equipped with HDMI 2.1 inputs that support auto low latency mode (allm). This allows the TV, if the connected console also supports allm, to automatically switch to game mode. In this mode, the lag is only 13ms: less than a single frame delay. This excellent result is achieved with both 1080p60 and 2160p60 images. Even if HDR images are offered, the input lag remains the same.
Hardcore gamers will certainly appreciate this device, because it can handle 120fps. This is possible thanks to the HDMI 2.1 inputs at the full 2160p resolution, but because there are currently no game consoles and video cards with HDMI 2.1, 1440p is the maximum resolution with which 120fps can be displayed. The next generation of consoles and video cards will of course change this.
This makes LG’s OLED televisions a future-proof choice for gamers. In addition, this TV supports freesync and Nvidia G-Sync. With this, game images ranging from 40 to 120fps can be displayed smoothly and this television is pretty much the perfect choice for gamers.
A lot of bandwidth is required to process UHD images at 60fps or higher. Most UHD TVs therefore use a trick called chroma subsampling to save bandwidth in the internal processing of images that come in via HDMI. Unfortunately, this costs some image quality, because the resolution of color in the image decreases. This is okay when displaying video, as all codecs used for video distribution apply the same trick to save bandwidth. However, with computer generated images, color artifacts may appear in the image. This is clearly visible, for example, with small, black letters on a white background.
With the default settings, the CX applies chroma subsampling to 2160p60 images presented at 60fps. It is easy to do something about this in the settings menu, by navigating to ‘View’> ‘Additional settings’. There you can choose to switch on ‘HDMI Ultra HD Deep Color’. This is possible for all four HDMI inputs. Once you have done this, all images will be displayed nicely at full color resolution and no artifacts will be visible.
Energy use and noise
Televisions with an OLED panel are not equipped with a backlight and can dim at pixel level. So no electricity is wasted in dark areas of the screen. However, energy is lost in the colors for the white OLEDs and the control electronics are not perfect. LG has nevertheless gotten the consumption in order in recent years and the OLED models have energy label A. Some LCD televisions are even more economical with electricity, but in terms of image quality they have to lose out against OLED.
A labelRight out of the box, our 48 “test model used an average of about 119W, producing 222cd / m² of brightness. After adjusting the brightness to 250cd / m², the average consumption increased a bit, to 124W. Who in the evening looks into a not too brightly lit room, can do with a brightness of 120cd / m² and if we adjust the CX to that, the consumption drops to an average of 84 W. Of course you can also have the brightness automatically adjusted to the ambient light, by means of the built-in light sensor, so you always have a beautiful picture and the TV does not consume unnecessary energy.
Compared to last year’s C9, not much has changed in the CX’s audio system. The declared total power is still 40W and a two-way speaker system has been used. The loudspeakers are mounted in the bottom of the housing and emit the sound downwards. The shape of the foot ensures that the sound is reflected slightly forward, and thus towards your ears. This gives you a nicer stereo image and voices can be heard more clearly. With wall mounting you do not have this advantage and the CX will sound less good.
The hardware of the CX may be almost identical to that of last year’s C9, the software is not. This year there is no longer support for dts sound. LG has chosen to save on DTS licenses, just like Samsung and Panasonic. Those who mainly watch video-on-demand services will not be bothered by this, but if you like to play movies in high quality from discs, you can run into this. Then you are obliged to use an external audio system with DTS support.
The CX does have support for Dolby Atmos sound, but of course the surround experience from a two-channel audio system is very limited. It is also possible to adjust the sound to the acoustics of your room. Test sounds are played which are then registered by the microphone in the remote control. This may resemble the acoustics measurements that the better AV receivers can perform, but on LG televisions this function is mainly for the show and the result seems to have little to do with the ‘measurements’.
Despite the fact that the CX’s audio system is equipped with a number of useless features, which seem to have been mainly invented to spice up the specifications, we are pleased with it. The sound can fill a large room and sounds nice and dynamic. The low reproduction is certainly not disappointing for a flat television and is clearly better than that of the average television. We recommend that discerning music and movie enthusiasts invest in an external audio system, but most people will be very satisfied with the sound from the CX.
The image results
With televisions based on LCD technology, you will see clearly less beautiful image if you do not look straight ahead. Especially when it concerns a TV with a VA panel. With OLED televisions, the image quality at an angle is almost as good as straight from the front.
With identical lighting, with the left photo taken from the front and the right at a 45 degree angle. The color saturation and contrast are still good at an angle. The brightness decreases a bit, but that effect is so limited that it is not noticeable with the naked eye.
The brightness of the screen is also much more uniform than with LCD televisions, because no backlight is used. We took pictures of a white screen where we exposed for medium gray, so that the uniformity of the screen can be seen extra well. We do not see large differences in brightness, such as with LCDs. We do see very small differences in the color balance in the photos, but when displaying normal images, these are completely unnoticeable to the naked eye.
The black level of OLED is simply perfect. When displaying black, no light comes out of the screen. As a result, the contrast of OLED televisions is much greater than that of LCD. Because the pixels can be turned off individually, the local contrast is just as great as the overall contrast. As a result, images on an OLED screen look sharper at the same resolution than on an LCD.
All LG OLED models, except those from the B-series, are equipped with the ‘α9 Intelligent Processor’, which has arrived in the third generation this year. This image processing chip makes it possible to display 4k images with a maximum of 120fps. Of course, LG has also built in the necessary algorithms that should improve the image in one way or another.
AI Image ProSince last year you can enable ‘AI image’ and this year this function has been given the suffix ‘Pro’. In one way or another, marketers at different brands tend to use the term ‘ai’ everywhere and so now an entire ai menu has even been added to the interface. In any case, we do not feel that AI image Pro works very intelligently. We don’t think it offers much more than some subtle sharpening. In any case, we did not think the image would improve.
There are two types of noise canceling available. There is one against normal noise in the picture, such as film grain or noise that is created by using high ISO values when recording. The other, called ‘MPEG Noise Reduction’, is designed to counteract the artifacts created by digital video compression. Both algorithms do what they are supposed to do and produce significantly less noise in the picture, but it is impossible to distinguish noise from subtle details perfectly. As a result, the image sharpness clearly deteriorates and it is better not to use noise reduction with good footage.
An image interpolation algorithm effectively increases the frame rate by calculating intermediate images. At LG, this function is called TruMotion and its effect is a smoother and sharper image with a lot of movement. Unfortunately, it is impossible to calculate perfect images in real time, so these types of algorithms always produce artifacts in the image with more complicated movements. LG’s TruMotion is one of the better algorithms, but especially when an object on the screen moves in front of a moving background, things go wrong and disturbing artifacts appear.
TruMotionIf you set TruMotion to User, you can enable OLED Motion. This is LG’s marketing name for black frame insertion, where a black image is always displayed after each frame. This makes movement clearly sharper. This is because the individual images are visible for a shorter time, so that if your eyes move to follow an object on the screen, there is less motion blur on your retina. This effect is comparable to using fast shutter speeds in photography. Unfortunately, this also greatly reduces the brightness of the image and you will have to deal with a clearly visible flicker. New is that you can play around with the settings to make the duration of the black images longer or shorter. Still, the blink effect continues to stand out clearly, which is why most people will not be happy to use it.
In our opinion, the vast majority of ‘image enhancers’ are better off, but the Maximum Brightness function can be very useful when viewing with a lot of ambient light. By letting go of the official specifications and deliberately displaying the shades of gray too brightly, you get an image that looks a lot better on a sunny day. You should not forget to turn the function off again in favorable light conditions, otherwise you will see a much too bright image.
Measurements and HDR
Due to the perfect black reproduction, OLED screens have an enormous contrast. This provides a great viewing experience because contrast is one of the most important properties when it comes to image quality. Ambient light causes reflections and thus influences the perceived black levels and contrast. The CX has an anti-reflection coating, but it is not as effective as that of some LCD televisions. This was a deliberate choice, because a better anti-reflection layer is at the expense of the local contrast, making the image look less sharp. It is therefore important to avoid excessively bright light sources in the viewing area.
Contrast is pretty much the most important quality when it comes to perceived image quality. Correct color reproduction is slightly less important, but certainly not unimportant for a beautiful image. We measured the color rendering with our SpectraCal C6 colorimeter, which we provided with a meter profile in Calman using an X-Rite i1Pro 2 spectrometer.
A gray scale measurement provides a good picture of the color reproduction, because if all shades are displayed without color cast, most of the colors are also displayed correctly. Moreover, we can see from this measurement whether the brightness increases with the correct steps, so that no details are lost in the image.
Of all presets, the ‘Film maker’ mode produces the best result. This mode does exactly what it was made for and displays the image as good as exactly as it was intended. With an average ΔΕ2000 of 1.5, all deviations are well below the limit of 3, making them invisible to the naked eye. The gamma curve is also very good and follows the 2.2 line almost perfectly. So there is hardly any profit to be made with a calibration.
We see a decent result with the primary and secondary color measurement. With a ΔΕ2000 of 3 deviations start to become visible to the human eye. The CX arrives at an average ΔΕ2000 of 1, which means that a calibration will not actually give any visible gain here either.
As far as hdr formats are concerned, there is support for Dolby Vision, Technicolor, hybrid log gamma and hdr10. So there is no support for hdr10 +, an extension to hdr10 that adds dynamic metadata and can mainly be found on Amazon Prime Video. That is of course a shame, but not an insurmountable problem, since all HDR10 + content can also be displayed without the dynamic metadata. LG tries to compensate for this by adding ‘HDR10 Pro’, a feature that is intended to simulate the effect of dynamic metadata. Of course we would rather have just seen support for hdr10 +.
The maximum brightness of OLED screens is somewhat lower than with the brightest LCD TVs, so you have to darken the room slightly when watching HDR for the best result.
With most HDR screens, the brightness decreases when large bright areas have to be displayed, but with OLEDs the brightness decreases even further with very bright images. This is because OLEDs, just like crt’s and plasmas, are equipped with an automatic brightness limiter (abl) that limits the power consumption of the screen with an (almost) completely white screen. In the graph above we see that the abl intervenes when twenty-five or more percent white must be displayed. This is clearly visible when looking at test images, but when looking at normal content it is almost never noticeable.
When reproducing a white area covering 10 percent or less of a black screen, we measured a brightness of nearly 640cd / m². At 25 percent the brightness drops to 362cd / m² and at 100 percent there is still 119cd / m² of brightness left. We saw the highest peaks in the Standard mode; with the other presets the brightness was just a bit lower. If a white area is displayed a little longer, the brightness first increases and then decreases again after a while. We measured a peak of 790cd / m².
When measuring hdr, we no longer express the deviations in ΔΕ2000, but use ΔΕITP. This was chosen because ΔΕ2000 was never designed to express deviations from light-emitting screens, and large deviations occur at higher brightnesses. You can read more about this subject here and here. The ‘Film maker’ mode produces the best results:
When displaying, HDR displays should cut brightness peaks above the maximum possible and display at the peak brightness of the display itself. So details in the highlights are lost. To preserve some more detail in the brightest parts of the screen, television manufacturers apply a certain amount of roll-off at the tipping point in the electro-optical transfer function . This is the function that, similar to gamma in SDR images, determines how bright a certain signal value should actually be displayed.
This roll-off of the brightness creates somewhat larger deviations around the tipping point. You can see this in the middle graph. In the top graph you can see the deviations where the brightness error has been disregarded. The measured color deviations are on average below a ΔΕITP of 3, making them barely perceptible to the naked eye. Brightness errors are included in the middle graph. The tipping point is even more visible here, but the average deviation is even a bit lower. A very good result. So there is no direct reason to calibrate, but if you want to do that, it can even be done completely automatically, provided you have measuring equipment and Calman software at your disposal. The pattern generator required for this is already built into the TV’s software.
We are very pleased with the CX because this TV scores well on almost all points. We were last year with the C9 too, but we found the awkwardly short power cord a downside. Unfortunately, the CX is also equipped with such a stingy short and detachable cord of which you barely have a meter left when you use the cable guide in the base. We do not understand that such an expensive TV should save on the power cord.
The image quality is simply great: the contrast is enormous, the viewing angles are very wide and the display is very accurate. The large contrast makes viewing HDR images an experience, but the maximum brightness is clearly less in a lot of ambient light, especially compared to expensive LCDs. Still, nowadays you can look good with a little more light in the viewing area, because the average brightness can be increased at the expense of some accuracy.
For gamers, the CX is an excellent choice. The input lag is low, there is support for variable frame rates in the form of freesync and G-Sync and, moreover, 4k images with 120fps can be displayed thanks to HDMI 2.1. Thanks to webOS and the Magic Remote, the operation is also pleasant and the sound is also excellent. It is a pity that support for dts sound has been discontinued this year.
Due to scarcity, the 48 “model we tested is still very expensive for the time being. More expensive even than the 55” version. It is nice that there is now a smaller size, but at the moment the price is really too high in proportion. Moreover, the differences with last year’s C9 are very small and it still supports dts sound. As long as the C9 is still available, that is in our opinion the better choice.