Samsung UE55JU6400 (JU6400) Ultra HD 4K TV Review

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Is this the emergence of the first truly mass-market Ultra HD TV?

by Steve Withers May 8, 2015 at 8:52 AM

  • SRP: £1,299.00

    What is the Samsung JU6400?

    When we asked the other TV manufacturers what was the toughest model to compete against last year, they often said the same thing - the Samsung H6400. It’s not hard to see why, that particular model was well designed, had great accuracy, along with comprehensive smart features and all for a very attractive price. It was also a Full HD model but with the continuing drive towards Ultra HD 4K, Samsung needed something new to offer this year if they wanted to build on the success of the H6400.

    Enter the JU6400 which represents Samsung’s entry level model in this year’s Ultra HD 4K range and seeks to deliver a similar balance of price and performance as the H6400. So you get a largely plastic but still attractive design, an Ultra HD 4K flat panel, quad-core processing and Samsung’s latest smart platform powered by Tizen. The JU6400 also uses a direct LED back light but sadly doesn’t include Samsung’s excellent local dimming; nor is there any support for 3D, although that probably won’t matter to most consumers.

    However, despite the absence of local dimming and 3D that’s still an impressive set of features and the JU6400 has a wide range of screen sizes and price points to gain the attention of consumers. At the time of writing (May 2015) you can pick up the UE40JU6400 for £699, the UE65JU6400 for £2,249 and the massive UE75JU6400 for £3,999. However the most popular screen size will probably be the 55-inch UE55JU6400 that we’re reviewing here and at just £1,299 it’s also got a tempting price tag. Let’s see just how tempting…


    The design of the 55JU6400 won’t win any awards and could even be considered boring coming from a company as innovative as Samsung, but we rather like its minimalist approach. After all it’s a TV at the end of the day, so ultimately what you’re really interested in is the picture on the screen. The JU6400 uses a flat screen, which will doubtless please those consumers who have yet to be convinced by Samsung’s more curvaceous models. Around the screen is a 1cm wide black plastic bezel with a brushed metal effect and the filter in front of the screen appeared very effective at minimising reflections. When stand mounted there is 7cm of clearance under the screen, which might be worth considering if you plan on using a soundbar.

    The panel sits on an attractive stand that uses a combination of black plastic and a silver brushed metal finish but it can’t be swivelled so, given the limited optimal viewing angles that we’ll discuss later, correct placement is important. The UE55JU6400 uses a direct LED backlight, meaning it’s a little wider with a depth of around 5 cm but that’s a small price to pay for a more uniform backlight. The overall build quality is reasonable but the plastic construction doesn’t feel as solid as some of Samsung’s more expensive models. However the JU6400 has been designed and constructed to meet a certain level of build quality and a specific price point, so based on that rationale it does exactly what it’s supposed to do.

    The design is simple and whilst the construction largely uses plastic, it remains an attractive looking TV.

    Connections & Control

    All the connections are at the rear right of the JU6400 as you face the screen and here you’ll find four HDMI inputs (with support for MHL and ARC), three USB ports and the DTV aerial socket which are all side mounted. We were pleased to see that these connections are all 27cm from the edge, which makes tidy cable management easier. On the back panel are some rearward facing inputs including composite and component video, stereo RCA audio in, a digital optical output, a 3.5mm headphone jack and an Ethernet port; along with a CI (Common Interface) slot. Also at the rear and just below the connections is a small joystick control and over on the left hand side is the connector for the provided 2-pin power cable that is 1.5m long.
    Samsung UE55JU6400 Connections & Control
    Samsung UE55JU6400 Connections & Control

    Unlike the more expensive models, the 55JU6400 only ships with one remote control. This is a standard Samsung remote, which is a large plastic affair with all the usual buttons. These are well positioned, with the most frequently used made easiest to reach when the remote is sat in your hand. There are a number of ways to bring up channel information when watching digital TV, along with the usual EPG features. The navigation of the smart TV system is easy and intuitive thanks to the direction and enter keys, so it’s no great loss that the JU6400 doesn’t come with the motion controller included with more expensive models. Overall the remote control is effective, well-proportioned and fits comfortably in the hand.

    Features & Specs

    Obviously the big feature as far as the JU6400 is concerned is that it uses an Ultra HD 4K panel with a resolution of 3840 x 2160 pixels. Since it’s a UHD TV it also supports both VP9 and HEVC decoding so you can watch streaming services from Amazon Prime Video and Netflix - depending on your internet speed of course. Although if you can’t currently take advantage of UHD streaming you can at least feed native 4K material into the TV via the USB ports.

    The 55JU6400 also sports Samsung’s Ultra Clear Panel which minimises screen glare, reduces reflections and rejects ambient light spill on the screen. The JU6400 doesn’t include Smart LED local dimming but does utilise a global dimming system for its direct LED backlight. The Smart TV system for 2015 has had a major overhaul and is now powered by the Tizen operating system. It moves away from full screen smart TV app pages and resembles the WebOS layout used by LG.
    Samsung UE55JU6400 Features & Specs
    Samsung UE55JU6400 Features & Specs

    All items on the JU6400, including source inputs, become apps in the system and allow easy navigation using a selection of cards which appear at the bottom of the screen. You can select or expand these cards to drill further down into the content you want or to simply change the source. From this card layout you can select video on demand services, games, social apps and more. The system was fast and stable thanks to the use of quad-core processing.

    There are also regular software updates which download automatically and run in the background when ready to update. Services available on the Smart platform include a full Samsung App store, all the UK catch up services (although some are still being added), 4K Netflix and Amazon Prime Video as well as Facebook, Twitter and other social media apps and games. We will have a full standalone review of the new smart TV system in the very near future, so stay tuned.

    Despite it’s lower-tier status the JU6400 still comes with a full suite of smart features and quad-core processing.

    Picture Settings

    To get the best out of your new UE55JU6400 we would recommend selecting the Movie Picture Mode, a Colour Tone of Warm2 and the Auto Colour Space, along with appropriate contrast and brightness settings. In our review sample this delivered a level of accuracy that was already below the general error threshold that we use in our reviews. In the video below we go through all these settings and also the detailed White Balance and Colour Space custom settings but given the excellent out-of-the-box performance, we would warn against just copying these settings. They probably won’t be necessary and they could make things look worse as each TV and viewing environment is different; instead we would suggest that you also follow our Picture Perfect Guide.

    You can see our suggested picture settings for the sample of the UE55JU6400 we review in this video:



    As we mentioned in the Picture Settings section, if you select the Movie picture mode, Warm2 colour tone and Auto colour space, you should get a very accurate out-of-the-box performance. We have been impressed with accuracy of Samsung’s TVs this year and that includes both review samples and retail samples that we’ve tested.
    Samsung UE55JU6400 Calibration
    Samsung UE55JU6400 Calibration

    The UE55JU6400 proved to be no exception and as you can see in the left hand graph below, the greyscale and gamma are both tracking very accurately. There is a slight excess of green energy in the greyscale but this wasn’t really noticeable in actual viewing material. The gamma was tracking around 2.4 which helped give the image a bit more punch.

    As we’d expect given the greyscale measurements, you can see the slight green push to white on the CIE chart below on the right. There’s also a slight over saturation of green, blue and yellow but otherwise this is an excellent colour performance. The majority of colours are close to their targets for Rec.709, the luminance measurements are good and the overall errors are all below three.
    Samsung UE55JU6400 Calibration
    Samsung UE55JU6400 Calibration

    Post Calibration

    Given such an accurate starting point, it was a relatively easy task to calibrate the UE55JU6400. Although the Samsung includes both a two- and a ten-point white balance control, we only needed to use the two-point to get the three primary colours balanced. The gamma was still tracking around 2.4 and the overall greyscale errors were all below one.

    The colour management system (CMS) included on Samsung TVs is excellent and allowed us to dial in all the primary and secondary colours to a reference level of accuracy. There was still a slight under-saturation of red that we couldn’t quite fix but it was still under three and the overall errors we well under one.
    Samsung UE55JU6400 Calibration
    The CIE tracking at lower saturation points was also very good for a TV in this price range. All the secondary colours were all tracking very closely to their targets (handy for things like flesh tones) and so were the primary colours, although there was a slight under-saturation at 75%. However overall this is an impressive level of colour accuracy for a lower-range TV.

    The out-of-the-box performance was excellent and there would be very little gained from getting the UE55JU6400 professionally calibrated.

    Input Lag

    Samsung have worked wonders when it comes to the input lag on their Ultra HD 4K TVs this year and this clearly extends to the entry models as well. Although if you're serious about your gaming, you’ll definitely need to use the Game Mode on your JU6400. That’s because in Movie Mode we measure the input lag on the 55JU6400 at 124ms, which is on the high side. However once we engaged Game Mode this dropped down to an impressively low 28ms, which means the UE55JU6400 was extremely responsive when gaming. The level of detailed provided by the higher resolution panel and the TV’s innate brightness made made gaming hugely enjoyable and the larger screen size added to the sense of immersion.

    Sound Quality

    The fact that the JU6400 uses a direct LED backlight has an added benefit when it comes to sound quality. The deeper chassis means there’s more room for larger speakers and, as a result, the overall sound is better. Although the included speakers are still downward-firing, the results were reasonably good with the 55JU6400 creating a decent front soundstage and the size of the screen delivering a better sense of stereo separation. In addition, the built-in amplification was capable of going relatively loud without distorting, although you can’t push it too high. The JU6400 handled dialogue well which meant it dealt with the majority of TV programmes without any issues. Where the audio became more complex it also managed to render music effectively but clearly if sound performance is important to you then you should always consider an outboard solution such as a soundbar.

    Samsung UE55JU6400 Video Review

    The JU6400 delivers a great picture for the money, with excellent colours, video processing and backlight uniformity.

    Samsung JU6400 Picture Quality

    The fact that the JU6400 uses a direct LED backlight meant that we expected to see a decent level of uniformity and so it proved. The screen was free of pooling, clouding or bright corners and edges, which is pleasing to see on a cheaper model. There was some minor banding where the LED backlights were visible as images panned across a uniform colour such as a blue sky or a green football pitch but this was rare and overall the 55JU6400 delivered an impressive performance in this respect.

    Video Processing

    Samsung’s video processing is generally excellent and as a result we expected the JU6400 to perform well in all of our tests. It did and the results were impressive, with the TV deinterlacing and scaling content effectively without introducing any obvious artefacts. The 55JU6400 passed all of our usual video processing tests and the performance was good regardless of whether the source content was standard or high definition. This is important because when it comes to Ultra HD 4K TVs most of the content you watch, for the time being at least, will be upscaled to match the higher resolution panel.

    Motion Handling

    As always we used our FPD Benchmark test disc to measure the motion resolution of the JU6400 at around 300 lines which is what we would expect from an LCD TV. What we didn’t expect was that turning on the Auto Motion Plus made no difference to the motion resolution. Normally we would expect a frame interpolation feature like Auto Motion Plus to deliver the full 1080 lines of resolution but in fact it appeared to have no affect at all, regardless of which option we chose. We can only assume this is due to a software bug and have reported our findings back to Samsung. As it happens we found the motion handling on the Samsung to be just fine without the need to resort to frame interpolation. When watching 24p Blu-rays with Auto Motion Plus off, the motion retained a suitably film-like quality and overall the motion handling on the 55JU6400 was perfectly acceptable.

    Black Levels & Contrast Ratio

    The JU6400 uses a VA panel but doesn’t have Samsung’s Smart LED local dimming. Instead it uses a form of global dimming, which meant that if we pulled up a 0IRE full screen raster the backlight went out and we measured 0.001cd/m2. Of course this isn’t representative of a normal image and using a 0IRE window we measured black at at 0.06cd/m2, which is the same as all the other Samsung TVs we have reviewed so far this year. The JU6400 also has plenty of brightness, easily hitting our target of 120cd/m2 and going as high 325cd/m2 with the backlight and contrast at their maximum settings. Although it should be stressed that the JU6400 doesn’t support High Dynamic Range (HDR). Using a brightness of 120cd/m2 and a black measurement of 0.06cd/m2, the JU6400 delivered an on/off contrast ratio of 2,000:1 and an ANSI contrast ratio of 1,655:1, which is actually pretty good for an LCD TV.

    Despite the absence of any local dimming, the black levels on the JU6400 were acceptable and there good detail in the highlights, although at the expense of some of the finer shadow detail. The big drawback for all the Samsung TVs that we have seen so far this year is their viewing angles. As long as you’re sat dead centre then the image looks great but as soon as you begin to move off-axis by even as little as 10 degrees, there is a deterioration in performance. Once you begin to move even further off-axis then the luminance, colour balance and black levels will deteriorate further. It’s a limitation of the technology but essentially with LCD you have two choices, either good blacks and limited viewing angles or poor blacks and wider viewing angles. Which is best will undoubtedly depending on where you plan on positioning the TV in your room but remember that the JU6400 can’t be swivelled on its stand, so take that into account.

    Ultra HD 4K Performance

    Using our Ultra HD 4K test material we put the JU6400 through its paces and were impressed at the quality of images that even this lower tier UHD TV was capable of producing. The level of detail was astonishing and when viewing from the optimal position the decent blacks, even backlight, levels of gradations and accurate picture all played a part in making the experience as enjoyable as possible. The amount of 4K content might currently be limited but there’s no doubt that once it becomes more common place the 55JU6400 will be able to take advantage of the higher resolution format, even if it doesn’t support other aspects such as a wider colour space or higher dynamic range (HDR).

    Full HD Performance

    While you wait for more 4K content, whether that's via streaming, broadcast or Blu-ray, the JU6400 is still capable of delivering a great picture from current sources. All the factors that made 4K content look so good still apply but the superb video processing also comes into play, deinterlacing where appropriate and scaling the image to match the native resolution of the panel. The result is that streaming content from Amazon, Netflix and Now TV all looked great and high definition broadcasts could really impress. The JU6400 was even able to produce a reasonable image with standard definition content, which is remarkable when you consider it’s interpolating most of the picture.

    However it’s with Blu-rays that the 55JU6400 really gets to show what it’s capable of and recent releases such as Interstellar and Inherent Vice looked suitably film-like. In fact the images produced by the Samsung were often so good that you almost forgot that they weren’t native 4K. The lack of local dimming is a shame and the viewing angles are limited but from the right position the picture was excellent with natural colours, plenty of detail and reasonable motion handling. Ultimately you can’t expect everything at this price point but, all things considered, the UE55JU6400 delivers a great picture for the money.

    How future-proof is this TV?

    4K Ultra HD Resolution
    HDR Support
    Colour Space (percentage of DCI - 100% best) 75%
    10-bit Panel
    HDMI 2.0a Inputs
    HDCP 2.2 Support
    HEVC Decoding
    4K Streaming Services
    Smart TV Platform
    Picture Accuracy Out-of-the-Box (score out of 10) 8
    What do these mean?


    OUT OF


    • Excellent out-of-the-box accuracy
    • Great colours & contrast performance
    • Impressive video processing
    • Low input lag
    • Decent set of features


    • Narrow viewing angles
    • Minor banding
    • No local dimming
    • No wider colour space or HDR support
    • No 3D support
    • Bug in Auto Motion Plus
    You own this Total 16
    You want this Total 2
    You had this Total 0

    Samsung UE55JU6400 (JU6400) Ultra HD 4K TV Review

    Samsung’s goal was to produce an Ultra HD 4K TV that could replace the hugely successful Full HD H6400 from last year, then it’s fair to say they achieved it. The UE55JU6400 has an attractive but minimalist design and whilst the build quality could be better, compromises need to be made at this price point. Thankfully there have been no compromises made when it comes to picture quality, with the JU6400 delivering a highly accurate image right out of the box. The UHD 4K performance was excellent, the black levels good for an LCD TV and the video processing was impressive. As a result even non-4K content looked great and the input lag was extremely low, making it ideal for responsive gaming.

    The 55JU6400 also includes Samsung’s latest smart platform which is powered by the Tizen operating system and although some features are still being added it certainly shows potential. Obviously to hit a specific price some features are missing, which means there’s no local dimming and no 3D, so bear that in mind if the latter is still important to you. The JU6400 also doesn’t support a wider colour space or higher dynamic range (HDR) but then this is an entry level model. Perhaps the biggest downside that the 55JU6400 has is that, due to the panel used, the optimal viewing angles are limited; this means that correct positioning is more important than ever. Otherwise the Samsung UE55JU6400 delivers a great package for its asking price, making it ideal for anyone looking to take their first steps in the world of Ultra HD 4K.

    Suggested retail price when reviewed: £1,299.00

    The Rundown

    Contrast/Dynamic Range/Black Level


    Screen Uniformity


    Colour Accuracy


    Greyscale Accuracy


    Video Processing


    Picture Quality


    Picture Quality Out-Of-The-Box


    Picture Quality Calibrated


    Sound Quality


    Smart Features


    Build Quality


    Ease Of Use


    Value for Money




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