The sharpness on show also helps give the image exceptional depth, as in the sequence where Hiro’s father and Angela Petrelli meet on the balcony of a penthouse flat with New York spreading all around them.

Next to impress is the image’s contrast, as the broadcast serves up a really quite extreme range between its peak whites and darkest blacks.

There’s definitely room for improvement, though, when it comes to noise in the picture. Some scenes, such as the shots of the new Mexican characters riding in the back of a truck, look really very noisy indeed, with quite overt dot crawl and colour noise. But there’s a slightly gritty look to almost every scene, especially over background walls.

One other less frequent problem is that the picture occasionally inexplicably looks a bit soft, such as with the shots of Matt’s face during his discussion with Molly’s teacher, and some dark scenes like the one where the two Mexican characters discuss a copy of Chandra Suresh’s book. Given the lack of any perceivable logic to when these soft moments occur, the blame for them probably lies with the HD source material rather than anything the BBC is doing wrong with its broadcast.

The overall impression is still pretty positive, though – especially when you compare it to the depressingly soft and ‘standard def’ look of the first episode of the new series of Battlestar Galactica I reviewed recently.

You can always tell how much care has gone into a sound mix by the amount of ambient effects you can hear spread around all five of your main speakers, and by the sense of space the mixing builds. And the Heroes audio mix scores highly on both counts. During the scene where Hiro’s father meets Angela Petrelli on a New York rooftop, for instance, the sense of a living, breathing city carrying on below them is superbly created, with individual voices and car horns cleverly overlaid against a general hubbub that spans your whole surround speaker system in exceptionally immersive fashion.

The soundtrack is also remarkably clear, with tiny little treble effects emerging without a trace of sibilance or harshness (check out the rain in the Irish ship yard sequence), and voices sounding rich and totally believable without ever becoming overwhelmed when there’s a lot of action going on.

During these action moments, of course, the soundstage bursts into life in impressive fashion, suddenly calling in a very healthy bass channel and kicking up three or four gears in an instant.

The last plus point is the series’ really exceptional score. There’s some kind of musical accompaniment to almost every scene, and without exception this music is perfectly mixed, spreading far and wide around your room, adding drama and pace in all the right places, yet never overwhelming the dialogue or subtle treble effects that give the soundtrack such a convincing sense of life.

And let’s not forget that the genuinely HD pictures are also joined by a truly excellent audio mix guaranteed to give your speakers the sort of work out usually only delivered by a high profile movie.