Like most of its competitors, the LM660T uses Edge LED backlighting with zone-by-zone brightness control—otherwise known as dynamic backlighting. As the name suggests, the LED backlights are positioned around the edges of the screen, a system we don't think is as effective as Full LED backlighting (with LEDs over the entire panel).
Like LG's other high-end TVs, the LM660T has the firm's stylish Cinema Screen design, and the screen bezel is just 5 mm thick. All in all, it's a pretty sleek piece of kit!
The LM660T is compatible with HbbTV for interactive viewing and live TV controls, and offers access to LG's Smart TV platform. This feature is particularly well designed, and the simple, smooth navigation is a real treat. However, there aren't that many interesting apps.
There haven't been any updates to the built-in media player, but that's no real problem since it handles pretty much any file you throw at it. The only thing it can't handle is movie chapters.
This TV can be controlled in three different ways. First of all, there's a traditional remote that's pretty standard fare and has no built-in backlighting. Next, there's the Wii-mote style device for motion control, which is fast and accurate to use—we're big fans! Finally, you can download an iOS or Android app to control the LM660T with your tablet or smartphone.
Colours in ISF Expert mode: average Delta E 3.4
You'll need to change a few settings in the internal menu (see inset) to get the best from this TV.
In ISF Expert mode, contrast measured at 800:1
The good news is that colours are reproduced accurately. We measured an average Delta E of 3.4 (the difference between perfect colours and those displayed onscreen, with anything under 3 considered accurate). Plus, with the gamma at 2.2 and colour temperature at 6409 Kelvins, we really couldn't ask for much more—it's perfect!
However, the big downside of LG's IPS screens is their low contrast. We measured just 800:1 in the LM660T, which is way too low! At best, you end up with a very dark grey instead of a real, deep black, which can be particularly annoying when watching films!
Although IPS screens have a great reputation for wide viewing angles and consistent display quality, you wouldn't guess that from this TV. The LM660T only scored 1.9/5 in our viewing angle tests and showed an average variation in brightness of 13% across the display. We've seen other types of LCD panel do better—Panasonic's Alpha-IPS panel, for example, scored 3/5 for viewing angels with just a 6% average variation in brightness over the screen.
This graph shows the ghosting time, measured in ms, which measures the time it takes this TV takes to entirely remove the previous frame. The shorter the time, the more fluid moving images will appear.
Unlike other types of LCD technology, standard IPS hasn't really seen its responsiveness improve. In fact, it's as slow as ever, with 12.5 ms on average compared with 7.5 ms for Alpha-IPS. Ghosting (shadow images trailing behind moving objects) could therefore prove problematic for some demanding users.
That's all the more of a shame since the input lag is really low in the LM660T. We measured an average of 33 ms, which won't penalise gamers at all.
Seeing as the contrast is so low, there were no problems with clouding in the LM660T.
For the last two years, LG has been using passive 3D technology rather than the active-shutter modes favoured by some manufacturers. The LM660T comes with four pairs of glasses, and these are lighter, more comfortable to wear and cheaper to manufacture than active-shutter models. However, overall resolution is slashed in 3D mode, as a passive 3D image is split in two for the left and right eyes—a 1920 x 540 pixel image for each eye works out at good old 720p.
In spite of that, overall quality in 3D mode is excellent. The passive 3D glasses are very comfortable to wear and barely reduce brightness at all, which is enough to make you forget about the reduced resolution. Plus, there's none of the shimmering effect you sometimes get with active 3D glasses. Passive 3D (with alternate lines sent to the left and right eyes) is less affected by screen responsiveness than active 3D and doesn't usually have problems with crosstalk (images for the right and left eyes spilling over onto one another).
Below—the result as seen through 3D glasses (Top: LG 47LM660T / Bottom: Philips 40PFL8606H
With a perfect result, we shouldn't see any trace of the 'R' frame on the left, and, vice versa, none of the 'L' frame on the right. For the time being, only plasmas from Samsung and Panasonic get this right.
Green zone = good /Orange zone = tolerated / White zone = denatured
Audio isn't a strong point for the LM660T. The model we tested had some build issues in the chassis, so each time there was an onscreen explosion or another loud noise, the plastics vibrated. As you can imagine, that gets quite annoying when you're watching an action movie. Plus, the only frequency band that's well rendered is the part of the spectrum that covers human voices. That's fine for watching TV shows, but for films you'll be much better off with a sound bar or home cinema speakers—even the cheapest options.
Our LM660T review ends on a good note, however. With power use under 1 W on standby and just 80 W in use (which works out at 131 W/m² for this 47" model), it bags five stars for power use.