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View Full Version : DirecTV truly "cd-quality"?


brazilhead
2013-12-08, 09:43 PM
I'd like to hear people's opinion of the audio quality of DirecTV. It's widely advertised as "cd-quality" (see the "Directv Latin America" subsection here: http://www.reuters.com/finance/stocks/companyProfile?symbol=DTV.O). However, I recently had a Diana Krall show pulled from TTD because it had "digital satellite broadcast" in the lineage. (That's what DirecTV is). I'm only learning about this, but Frequency Analysis with Audacity of one of the Diana Krall files uploaded seemed to indicate lossless, while FA with EAC had the characteristic loss of db at 16KHz. (However, FM sourced shows also seem to have this drop on EAC.) Spectral analysis with EAC seemed to indicate lossless.

I just know that, to my ears, this show and the others I was planning to upload of other artists really do seem to be of cd-quality. However, I've looked around quite a bit on the Internet but can't find any technical specs of just what DirecTV's "cd-quality" exactly is. Any ideas here?

AAR.oner
2013-12-09, 05:46 AM
their use of the term "CD quality" is kinda meaningless...technically speaking, its not -- all digital cable/satellite/etc is broadcast lossy

if i remember correct, DirecTV audio is usually AC3 [Dolby Digital Plus]

paddington
2013-12-09, 09:27 AM
good morning

The advertisement of "CD-quality" is a subjective assessment that cannot be quantified.

If it said "CD-spec", then we can show that it certainly is no where near that.

As far as the "quality", XM radio had to quit using "CD Quality" because so many people realized it didn't even come close to CD audio or FM Radio. It was misleading, as XM / Sirius generally sounds like shit.

DirectTV audio uses lossy data compression, meaning a good 90% of the audio bits are discarded to save bandwidth, much the same way MP3 encoding does. I think it's AC3, but it doesn't really matter which codec, if we're comparing to CD audio standards. Lossy is lossy.

TTD requires all audio torrents to be lossless (no data compression), which would exclude anything sent over satellite as none of the major services send lossless, uncompressed audio. Check the FAQ for more info.

CD Audio is 44,100 Hz @ 16 bits, 2 channels with no data compression. All the bits are there.


Calling DirecTV audio "CD Quality" is, to me, misleading, since it shares none of the characteristics of CD Audio, aside from having 2 channels. That is a judgement call but, the fact that the audio is run through lossy data compression is not. It's factual and excludes it from TTD.


If you;d like to post a 2 min sample file, I will analyze and give you an idea of what lossy characteristics it exhibits.

brazilhead
2013-12-09, 12:30 PM
OK, thanks for clearing that up.