Opera from the Met on Sky Arts 2: sound quality

[underthecountertenor]

Sky Arts 2 is currently showing recent (2011ish) opera productions from the Met on Sunday evenings. I've recorded the first 3 (Il Trovatore, Don Carlo and La Fanciulla del West) but so far have only had the chance to watch Act 1 of Il Trovatore. I've recorded off the HD channel with surround sound. So far I have found the sound quality to be rather unsatisfactory: inconsistent, occasionally occluded and with odd balance. I have reasonably good equipment (an Arcam processor and B&W satellite speakers), and other HD surround programmes sound fine on it. Has anyone else had a similar experience? Should I perhaps forget the surround sound on this occasion and take it in stereo? If the rest of the broadcasts are like this I may decide not to waste my time or my disc space, and delete the lot.
Any comments or advice would be greatly appreciated.

[Bryn]

As far as I am aware (though happy to be corrected if I've got it wrong), Sky Arts HD uses but 320kbps AAC-LC to represent all six channels of surround sound. That's the same data rate Radio 3 HD Sound uses for just 2 channels of stereo. If it's anything like BBC HD on Freeview, only 128kbps HE-AAC is used for the 2 channel stereo option. At that sort of data rate I would not expect the audio quality to be much different from that offered by Radio 3 DAB.

[underthecountertenor]

Thanks for that Bryn. That (I think, as a technophobe, or at least techgnostic) explains a lot. What a shame!