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Topic: Can not tell difference between these samples (Read 20825 times) previous topic - next topic

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Can not tell difference between these samples
Reply #25
It is technically more difficult to do an ABX with an analog reference but it can ans has been done.


We did our first ABX test in 1977 but digital media was not widely available until 1983, so for 5-6 years all ABXing was done entirely in the analog domain.

Quote
The results indicate that some digital equipment is not up to par and a lot of analog equipment introduces distortion but Nyquist and Shannon were right - digital representations have quantization and bandwidth limitations but are otherwise true to the original.


On balance coming up with digital gear that *is* up to par is pretty easy these days.

Just about every commercial recording made in the last 20 years spent at least part of its life in the digital domain. There is no doubt that circumventing this caused potentially audible sound quality loss.

Can not tell difference between these samples
Reply #26
Your -q 10 Vorbis sample is fine. I decoded it with foobar and created a time aligned reference sample from my lossless "Dream Theater - In the Presence of Enemies Part 2" rip. I couldn't hear a difference in a quick ABX test. In my opinion the sample is not very demanding. I guess -q 4 or even a lower setting would be fine for this part of the song.

Probably your player is causing the problem.


Alex, thank you very much for both listening and giving the links, indeed updating the firmware did the trick.
Curiosity: why was it your guess that -q 4 should be sufficient? That is, what do you base your choosing of compression on?

Can not tell difference between these samples
Reply #27
Saratoga is a jerk. I think this is (or was, back when everyone was more on the original topic ) an interesting OP and the info you guys have given out has taught me a lot. I'm not an audiophile (as we speak I'm ripping CD's to 320 VBR AAC in favor of FLAC), but I find the subject fascinating nonetheless.

  • tpijag
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Can not tell difference between these samples
Reply #28
You joined just to post that? Looking forward to when you actually contribute something.

  • Alex B
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Can not tell difference between these samples
Reply #29
Anyway, thanks for bumping this. I didn't notice the OP's question that was directed to me earlier.

Alex, thank you very much for both listening and giving the links, indeed updating the firmware did the trick.
Curiosity: why was it your guess that -q 4 should be sufficient? That is, what do you base your choosing of compression on?

My guess regarding -q 4 is based on my general experience of Vorbis (especially aoTuV which tends to be better than the reference version at low bitrates). Except for some rare problem samples, -q 4 is often transparent or at least not annoying in a critical ABX test. Even when the encoded material is not exactly transparent -q 4 rarely produces ugly artifacts that would be instantly noticeable without direct comparison to the lossless source file. Already in Sebastian Mares' first public listening test from the year 2005, the then current aoTuV version at -q 4.25 got an average score of 4.73 and didn't fall below 4.5 with any of the tested samples (on the scale from 1 to 5, in which 5 is imperceptible and 4 perceptible but not annoying). In my experience, even a lower q setting is usually fine for casual listening. I wouldn't hesitate encoding at -q 3 for a portable if the storage capacity is limited.

EDIT

I don't mean that an even lower -q setting like -q 2 or -q 1 could not be sufficient as well, but probably I would hesitate a bit and do some listening tests before encoding lots of files.
  • Last Edit: 11 May, 2011, 04:21:07 AM by Alex B