LED TV Showdown

2. Toshiba Regza 46SV670U

LED-backlit HDTVs are coming out in force in 2009-2010. Here are two models in the 40-49 inch range that should suit any home theater enthusiast well.

Our Readings

Real Contrast:	1677:1
Blacks:	0.12 cd/m²
Gamma Quality:	4.5/5
DeltaE 94:	5.1
Average discrepancy across whole display:	9%
Viewing angles:	1.7/5
Energy Consumption:	0.15 W / 216 W
Multimedia player:	1.7/5

We take these measuements using the best settings for watching a movie. Cinema mode is generally the one we use. Wherever possible, we set the white levels at 200 cd/m².

At last it's time for us to test a Toshiba TV--and not just any Toshiba TV, because today we're looking at the 46SV670U with LED backlighting.

Build Quality and Design

More accurately, the backlighting system in question uses local-dimming LEDs, a network of LEDs behind the display that should produce a more even light and more accurate dynamic backlighting.  The downside of this system is that the television itself has to be a lot thicker, with the frame measuring 9.4 cm from front to back on the 46'' version.  The last thing to note about the 1080p Full HD display is that it sits underneath a glossy layer that suffers from reflections.

Image Quality

Switching to Cinema mode improves the problematic curve, producing a much more natural image.  The blacks are however a little too light at 0.12 cd/m², compared to some of Toshiba's competitors which are below 0.05 cd/m².  The colors are also more accurate, but still far from perfect: the deltaE 94 hangs at 5.1 when it should really be under 3.0.  When we took the same measurements at a 45° angle from the centre line in every direction the results were pretty bad: deltaE shot up to between 8 and 10 and whites became far too bright.  Wide viewing angles are certainly not a boast the 46SV670U can make!  HD content still looks good if you're looking straight at the screen, and SD content benefits from decent upscaling, even if dedicated players do it better.

The gamma curve (left) and color temperature (right) are both very close to the standard we expect--well done!

The Active Vision M240HD filter does a good job of improving the fluidity of movements, but the price you pay is a reduced quality image overall with too much ghosting. 

Overall, the picture might seem gloomy, but don't forget that the Regza 46SV670U is one of the first televisions to undergo our updated 2010 test procedure, which is more demanding in several areas, including viewing angles.  The image quality it provides is perfectly decent, and the majority of viewers will be happy, but if you need particularly wide viewing angles, you should avoid it at all costs.

Sound Quality: A rare success story

We've often noticed that larger TVs often offer the best quality sound, partly because of the extra room that's available for the speakers. The 46SV670U confirms this trend, with very decent audio, compared to the majority of its competitors at least.  It's still a long way from being able to rival decent dedicated Home Cinema sound system.

Energy Consumption: Greedy!

The 46SV670U had a nasty surprise in store for us at the end of the test: when it's switched on, it uses around 216 W, not much less than a comparable plasma.  Or, to put it another way, that's one of the worse results we've seen on an LCD TV for a long time.  If you use the default settings, you can get that down to 143 W by turning off the LEDs in the darkest areas, but that has a negative impact on the display quality.

Fortunately things on standby are better, with a consumption of around 0.15 W.

Without being excellent, the 46SV670U puts in a decent performance and produces a reasonable quality image. It's hot on the heels of the leaders of the pack, but hasn't quite got what it takes to overtake.