Samsung as usual provides one of the best picture-adjustment suites for both 2D and 3D sources, delivering extras that many TVs lack like adjustable custom dejudder, a 10-point grayscale, and color management.
When this review first posted we wrote that picture settings can't be adjusted in Netflix, but that's incorrect. Calling up the Tools menu and then pressing the main menu button brings up picture adjustments in Netflix. Vudu's picture can also be adjusted, although we didn't try other services.
3D settings are the same as last year, and provide plenty of control as well. You can use the 2D-to-3D conversion system with streaming services and other sources we tried.
|HDMI inputs||4||Component video inputs||1|
|Composite video input(s)||1||VGA-style PC input(s)||1|
|USB port||3||Ethernet (LAN) port||Yes|
Like past superthin Samsung TVs, the D6400 doesn't have many analog connections and those it does have include require breakout cables (included). We'd like to see a headphone jack, but the third USB port might make up for that lack if you're using the Wi-Fi dongle and you like to stream media via USB.
All told the Samsung UND6400 is one of the better-performing edge-lit, LED-based LCDs we've tested, delivering solid black-level performance and very accurate color in bright areas, as well as excellent video processing. Sticklers for uniformity and off-angle viewing will be disappointed, as usual, and of course we found its glossy screen finish a liability in bright rooms. One pleasant surprise, however, was 3D performance, which seems much improved over last year even on this 120Hz model, albeit still not as good as on the best plasmas.
In default Movie mode the Samsung was characteristically accurate enough, delivering a relatively smooth grayscale overall, albeit a bit minus-red, and gamma that came close to our target. Calibration improved matters even further, thanks to the 10-point system and the extensive CMS, which worked very well. The latter was particularly helpful because luminance of the primary red in the default Auto color mode was significantly brighter than it should be. For our image quality tests we checked out "Hereafter" on Blu-ray.
|Comparison models (details)|
|Sony KDL-46EX720||46-inch edge-lit LED-based LCD|
|LG 47LW5600||47-inch edge-lit local dimming LED-based LCD|
|Samsung UN46C6500||46-inch edge-lit LED-based LCD|
|Samsung LN46C630||46-inch LCD|
|Vizio XVT553SV||55-inch full-array local dimming LED-based LCD|
|Panasonic TC-P50ST30||50-inch plasma|
|Pioneer PRO-111FD (reference)||50-inch plasma|
Black level: The Samsung UND6400 showed a darker shade of black than the Sony and the LG, and about the same as the Panasonic and the other two Samsungs, making it one of the better edge-lit LEDs we've tested in this category. As expected it couldn't compete with the Pioneer or the Vizio, however. The dark apartment in Chapter 2 of "Hereafter" provided a good test, and the D6400 reproduced the letterbox bars and people's silhouettes with relative realism. Shadow detail was a strength, surpassing the older Samsungs, the LG, and the Panasonic at properly resolving areas like George's darkened hairline.
Our major complaint in this area had to do with the D6400's penchant for turning its backlight off completely during some fade-outs, which can be distracting. One example occurred at the 6:48 mark, after Marie drowns in the tsunami--none of the other displays, including the C6500, showed similar backlight turn-off.
Color accuracy: Like many LCDs, the Samsung's main color weakness appeared in near-black and dark areas, which were tinged blue--it was as noticeable as on the Sony and worse than on most of the others. In brighter areas colors were exemplary, however, and even better than the Sony in the pre-tsunami, sunlit market from Chapter 1, for example, with its natural-looking leaves, fabrics, and skin tones. Overall we'd rate the D6400 a bit below the Pioneer and Vizio in this category, and better than the others, including the C6500.
Video processing: As usual we really appreciated Samsung's ability to adjust dejudder to preserve the cadence of film while reducing blurring. In our tests it handled 1080p/24 properly in Custom mode with Judder reduction set at zero and delivered full motion resolution with blur reduction at 10. A variety of other settings are available if you like some smoothing introduced, and all of them preserved the excellent motion resolution (although, as usual, the benefits of said preservation were very difficult to see in most material).
Uniformity: Most edge-lit LED-based TVs struggle in this category and the D6400, while better than some we've tested, still had plenty of issues. In dark scenes we noticed that the corners showed up brighter than the rest of the image, and while the difference wasn't as apparent as on the Sony or the C6500, for example, it was worse than on the non-LED-based C630. From off-angle the UND6400 lost black-level and color fidelity at roughly the same rate as the other LCDs, with the exception of the LG--which kept color fidelity better but lost black level at a greater rate.
Bright lighting: The glossy screen of the UND6400 was the second-worst in our lineup at reducing glare from bright reflections (the UNC6500 was just a bit worse). On the other hand, it excelled at preserving black levels under the overhead lights, beating the rest of the TVs in that category. As usual the matte LCDs, such as the LG, Sony, and Vizio, were the best overall at bright-room performance.
PC: The Samsung performed well in this category. Via VGA edge enhancement was present after the auto adjustment, but a tweak of the sharpness control (which is labeled "Fine" under the PC screen adjustment menu) to 30 removed it without introducing undue softness. We also saw some very minor flicker in test patterns and fine areas, but it wasn't an issue on most PC material and was less obvious than on the Sony EX720, for example.
3D performance: While the D6400 can't beat the best 3D plasmas we've tested, it's probably the best LCD we've seen yet for 3D (it's also the first of the 2011 model year we've tested). Samsung improved a couple of key aspects of 3D in 2011. The Bluetooth glasses sync with the TV more easily, keep their sync better, and best of all create an onscreen notification when first synced.
Picture quality in 3D was also noticeably better on the UND6400 compared with the UNC8000 from 2010. Watching "How to Train Your Dragon," we noticed quite a bit less crosstalk throughout the film, particularly in darker areas like the castle interior in Chapter 5. We still saw those characteristic double images, however, for example in the pillar and around the face of Hiccup in the background of the mead hall.
Compared with the other 2011 3D models in our lineup, the LG LW5600 (a passive LCD) and the Panasonic ST30 (an active plasma), the Samsung D6400 was our favorite for 3D picture quality. Its image was brighter and more striking, with significantly better black levels in 3D than the Panasonic, and crosstalk between the two was similar--if anything, the Samsung had a slight advantage in this area.
The LG meanwhile was the brightest, and virtually crosstalk-free, but black levels were poor and worst of all it suffered from the distracting aliasing artifacts we saw on the passive Vizio XVT3D650SV. At 47 inches, softness in the LG's 3D image wasn't a major problem, but in a side-by-side comparison the Samsung D6400 and Panasonic were sharper in areas of fine detail, such as the moss and crags in Chapter 6.
Note that as usual we tested these sets in the default Movie or Cinema settings for 3D; we don't calibrate 3D TVs yet.
|GEEK BOX: Test||Result||Score|
|Black luminance (0%)||0.0064||Good|
|Near-black x/y (5%)||0.2947/0.2865||Poor|
|Dark gray x/y (20%)||0.3118/0.3287||Good|
|Bright gray x/y (70%)||0.3126/0.329||Good|
|Before avg. color temp.||6604||Average|
|After avg. color temp.||6518||Good|
|Red lum. error (de94_L)||0.0958||Good|
|Green lum. error (de94_L)||1.4247||Good|
|Blue lum. error (de94_L)||0.5909||Good|
|Cyan hue x/y||0.2243/0.3255||Good|
|Magenta hue x/y||0.323/0.1508||Good|
|Yellow hue x/y||0.4204/0.4991||Good|
|1080p/24 Cadence (IAL)||Pass||Good|
|1080i De-interlacing (film)||Pass||Good|
|Motion resolution (max)||1200||Good|
|Motion resolution (dejudder off)||1200||Good|
|PC input resolution (VGA)||1,920x1,080 pixels||Good|
Power consumption: Samsung's UN46D6400 deserves plenty of credit for its miserly energy use, although it can't approach the efficiency of the Sony KDL-46EX720 and even costs a bit more to operate (95 cents per year) than the 2010 Samsung equivalent.
|Samsung UN46D6400||Picture settings|
|Picture on (watts)||86.37||81.51||38.28|
|Picture on (watts/sq. inch)||0.1||0.09||0.04|
|Cost per year||$18.98||$17.91||$8.43|
|Score (considering size)||Good|
(Read more about how we test TVs.)