Face off: Ultra HD 4k TVs

Sony KD-55X9005A VS LG 55LA9700

On first inspection both the Sony KD-55X9005A and LG 55LA9700 appear to be all about audio. Although it has a beautifully sculpted gloss black look that uses a single pane of glass across the front, the KD-55X9005A has powerful Magnetic Fluid speakers on each side, making it much, much wider than most 55" TVs, and it sits on a large circular pedestal stand that gives it a much larger footprint. Sound is obviously just as important to LG, whose designers have cleverly fitted the 55LA9700 with Sliding Speakers. Switch on the TV and a motorised speaker appears from between the two feet on either corner. When it comes to panel depth, the LG is slimmest, measuring 40.2mm to Sony's 58mm. On instant wow factor, the LG just edges it.

Both TVs have a resolution of 3840x2160 pixels, which creates an eight megapixel image known as both Ultra HD and 4k. That megapixel rating may not seem much compared to what digital cameras are capable of, but existing HDTVs only manage two megapixels. Crucially, both of these TVs use advanced, but very similar LED screens. Sony's is called Triluminos, with red and green filters on each LED to produce more finely graded colours, while LG's is called Nano Full LED. Both are capable of local dimming, which means that contrast levels are high, so bright white and deep black can be displayed simultaneously. Best of all, both the LG and the Sony use the passive 3D system - it means you can watch in 3-D using the same cheap, lightweight glasses used in 3-D theatres. Considering their near-identical panels, this category produces no winner.