The 40RV753B is equipped with Sound Navi technology, which projects sound from the integrated speakers onto the nearest hard surface where it's amplified.
On paper this method doesn't sound too promising, but in practice it works surprisingly well, producing a reasonable amount of bass and clear, audible speech that satisfies the sonic demands of most TV programmes.
But you'll definitely need a home cinema system if movies are on the menu, as the sound isn't loud or expansive enough to do justice to Blu-ray soundtracks. Turn it up loud and you get shrill, fatiguing high-frequencies. The other on-board audio technology, such as Bass Boost and Dolby Volume do exactly what they say on the tin, making this a decent sonic performer overall.
For a set that offers DLNA networking, Freeview HD, plentiful connections and useful picture tech, that £550 price tag is extremely reasonable. In fact it makes the 40RV753B an absolute bargain. A similarly sized set like the Samsung LE40C650 might offer features like 100Hz processing, Internet@TV and more versatile DLNA media streaming, but it's at least £100 more expensive and offers only slightly superior picture quality.
Similarly, the Sharp LC-40CT2E also costs more but offers nowhere near as many features as the Toshiba and provides inferior pictures. So for all the 40RV753B's performance shortcomings, judged against the budget competition it's actually a very impressive proposition.