ACOUSTIC SURFACE

Sony’s genuinely innovative solution here is to use the whole front of the TV as a flat-panel speaker, excited (vibrated) from behind in what Sony calls Acoustic Surface technology. It makes great sense — as TVs get bigger, even integrated speaker get physically divorced from the screen; here the screen itself makes the mid and high-frequency sound, so the sound comes directly from the image, and of course from a far wider area than a humble speaker cone can present, a full 65-inch diagonal indeed on the larger A9F!

Another advantage of flat-panel radiation is lower drop-off of volume level with distance compared with conventional cones, which might be handy if your family sits at different distances from the screen.

The screen vibrates in stereo, too — there are three actuator pairs on the back of the A9F (one pair more than on the A1); these vibrate the OLED panel and its bonded glass (which unlike LED-LCD requires no air gap) directly. There’s a pair of separate subwoofers behind the screen; these are mounted within the top of the stand on the 55-incher and so fire out sideways. The power quoted by Sony for the sound system is 6 x 13W (so presumably for the actuators), plus 2 x 10W (presumably the subwoofers).

This ‘invisible’ built-in audio proved well up to the level of a simple soundbar, and far better in some ways — a natural tone and a good level available. There’s no TV-like thinness, the crossover between rear sub and the screen’s mids and highs is impressively smooth. We even let the ‘surround’ effect do its work on multichannel soundtracks, widening the soundfield over the screen-bound flat sound — this is presumably what Sony advertises rather dramatically as Cinematic S-Force Front Surround. In a separate menu you can vary this surround effect between 0 and 12; we thought about halfway was enough.

We find this Acoustic Surface delivery of sound a little sonic miracle. While a good attached stereo system or full surround set-up will take things still further, the TV’s own sound is sufficient for even quite loud movie soundtrack playback in a medium-sized room. We’d even take this over the bars attached to some other premium TVs. And it further reinforces the Sony’s trump card — neatness, just the picture, nothing else to see.