As well as two 10W speakers in the TV's undercarriage, there's a third speaker on the back of the Sony KDL-55HX823. We obviously weren't able to test the behaviour of this trio while wall-mounted, but when placed close to a wall on its desktop stand it did seem to add a little power to our TV's sound.
Tested at loud volumes, the slim cabinet doesn't rattle, and while dialogue is handled best of all, we were reasonably impressed by the Sony KDL-55HX823's overall performance with both music and Avatar's soundtrack.
Can any television be worth this much? Although it's at least £1,000 cheaper than its similarly-specc'ed forbear from 2010, we would question how much anyone is prepared to pay for slimness. That £2,299 price tag seems steep.
Yes, there's a lot more to the KDL-55HX823 than its 27mm slim cabinet would suggest, but with perfectly respectable 50-inch plasma TVs from the likes of Samsung and Panasonic selling for half the cost, it's hard to justify – especially with Panasonic's identically sized and similarly priced TX-P55VT30B plasma TV in the running.