Bottom line: Which one is better?
Samsung JU6500 is better when we compare JU6500 Vs JU6400 because it has better sound quality, better picture quality in both dark and bright rooms.
Stand; the two TVs have stands.
Borders; Samsung JU6500 has 0.67” (1.7cm) whereas Samsung JU6400 has 0.63” (1.6cm).
Native contrast; Samsung JU6500 has 29.47:1 whereas Samsung JU6400 has 706:1
Local dimming; the two TVs don’t have local dimming.
SDR real scene peak brightness; not tested.
HDR real scene peak brightness; not tested.
Gray uniformity; Samsung JU6500 has 7.2 while Samsung JU6400 has 7.1
50% Std. Dev; Samsung JU6500 has 2.793% while Samsung JU6400 has 4.062%.
50% DSE; Samsung JU6500 is 0.197% while Samsung JU6400 is 0.184%.
Viewing angle; Samsung JU6500 has 4.2 while Samsung JU6400 has 6.9
Black uniformity; Samsung JU6500 has 7.8 while Samsung JU6400 has 5.1.
Reflections; Samsung JU6500 has 8.0, the same as Samsung JU6400.
Screen finish; Samsung JU6500 and Samsung JU6400 have semi-gloss.
Pre calibration; Samsung JU6500 has 9.0 whereas Samsung JU6400 has 6.0
White balance dE; Samsung JU6500 has 5.21 whereas Samsung JU6400 has 5.21.
Color dE; Samsung JU6500 has 1.34 while Samsung JU6400 has 3.24
Gamma; Samsung JU6500 has 2.24 whereas Samsung JU6400 has 2.25.
Post calibration; Samsung JU6500 has 9.8 while Samsung JU6400 has 9.7
White balance dE; Samsung JU6500 has 0.22 whereas Samsung JU6400 has 0.62.
Color dE; Samsung JU6500 has 0.26 while Samsung JU6400 has 0.30
Gamma; Samsung JU6500 has 2.20, the same as Samsung JU6400.
Color gamut; the two TVs have 7.1
Wide color gamut; both TVs don’t have.
Response time; Samsung JU6500 has 8.1 while Samsung JU6400 has 9.7
Flicker-free; Samsung JU6500 and Samsung JU6400 have 4.8
Black Frame Insertion (BFI); Samsung JU6500 and Samsung JU6400 have optional BFI.
Motion interpolation; Samsung JU6500 and Samsung JU6400 have motion interpolation (30fps).
24p Judder; the two TVs are not judder-free.
Native refresh rate; each TV has 60Hz.
Input lag; Samsung JU6500 and Samsung JU6400 have 8.7
Supported resolutions; Samsung JU6500 has 9.0 whereas Samsung JU6400 has 6.0
Total inputs; each TV has 1 Digital Optical Audio Out, 1 Analog audio out 3.5mm, 1 shared component in, 1 shared composite in, 1 Tuner (Cable/Ant) and 1 Ethernet. Samsung JU6500 has 4 HDMI and 3 USB while Samsung JU6400 has 3 HDMI and 2 USB.
Inputs specifications; the two TVs support CEC, HDCP 2.2 and USB 3.0. Samsung JU6500 supports HDR10 and HDMI 2.0 Full Bandwidth.
Audio pass-through; each TV supports ARC, 5.1 Dolby Digital and 5.1 DTS.
Low-frequency Extension; Samsung JU6500 has 95.00Hz whereas Samsung JU6400 has 134.00Hz.
Max; Samsung JU6500 has 93.4dB SPL while Samsung JU6400 has 91.2dB SPL.
Weighted THD @ Max; Samsung JU6500 has 0.115 while Samsung JU6400 has 0.010.
Smart OS; Samsung JU6500 and Samsung JU6400 operate on Tizen.
Interface; not tested.
Ad-free; Samsung JU6500 and Samsung JU6400 have 5.0
Ads; Samsung JU6500 and Samsung JU6400 are ad-free.
Apps and features; not tested.
Remote; not tested
TV controls; not tested.
Power consumption; Samsung JU6500 has 80W while Samsung JU6400 has 75W
Power consumption (Max); Samsung JU6500 has 177W whereas Samsung JU6400 has 165W.
Samsung JU6500 is better in this review as it has better sound quality and better picture quality in both dark or bright rooms.$