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Lossless vs 320kbps vs 256kbps, Moderation: no actual ABX results to see here.
agatha1
post Nov 17 2011, 12:22
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Hello everyone and thanks for making this forum what it is, I think the best audio forum in the world.

This is my first post here and I'm a little bit concerned about my ABX blind test results. I currently have over 6 TB of music, mostly FLAC and mp3 at 320kbps, but I also have some rips at 192 or below.

Now I want to standardize my whole collection and see if I can save a lot of Hard disk space or if I need to get better rips for part of my collection, etc. So, after some very interesting reading here, I decided to perform my own set of ABX blind tests, downloading foobar2000 and the ABX plugin.

Of course for some simple songs I can't tell any difference even between FLAC and 128 kbps, but I want a standard for my whole collection, including a lot of classical and progressive rock, so I need to find a bitrate that ensures me that I will ALWAYS have the best quality I can hear.

I tried the test first with Camarillo Brillo (by Frank Zappa), which I think it's a very good song for this test, because at the very beginning, after only 4 seconds, there is a kind of rattlesnake (sorry, I don't know the name of the instrument), which sounds definitely different at every bitrate. I encourage everybody to use this song for testing, as it makes it very quick.

Now, my results:
FLAC vs 256: I can always tell the difference, 10 out ot 10 times.
but here's the strange thing:
FLAC vs 320: Not clear
320 vs 256: Not clear.

¿Does this make any sense to you?
And if so, ¿Which is the bitrate I should stick to for my whole collection?

Thank you in advance for any help.

Regards from Spain,
Agatha.
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pdq
post Nov 18 2011, 12:54
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Indeed it is possible for a defect in hearing to make one more sensitive to certain kinds of artifacts, though I'm not convinced that is what is happening here.

Are you performing proper double blind ABX tests?

Have you checked the sizes of your files to make sure the 256 kbps files are really 256 kbps?
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Remedial Sound
post Nov 18 2011, 17:50
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QUOTE (pdq @ Nov 18 2011, 06:54) *
Indeed it is possible for a defect in hearing to make one more sensitive to certain kinds of artifacts, though I'm not convinced that is what is happening here.

Are you performing proper double blind ABX tests?

Have you checked the sizes of your files to make sure the 256 kbps files are really 256 kbps?


There might also be a subtle loudness difference between the lossy and lossless versions being tested that's tipping off which is which. I haven't ABX'd in a long while but IIRC foobar's implementation levels the loudness of the audio samples to keep this source of error in check.

Knowing what we know of lame and transparency, it's doubtful (but not impossible, I suppose) that someone can consistently ABX 256 kbps across a broad range of music. Test logs would be good.
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Posts in this topic
- agatha1   Lossless vs 320kbps vs 256kbps   Nov 17 2011, 12:22
- - db1989   1. Moved to Listening Tests 2. Post test logs, ple...   Nov 17 2011, 12:29
|- - agatha1   Hi db1989, 1.- Thank you for moving my post to t...   Nov 17 2011, 12:53
- - Jillian   I think the answer is very clear, if you're ha...   Nov 17 2011, 14:57
- - shadowking   IMO stay around 224k and not more as there is extr...   Nov 17 2011, 14:58
- - mixminus1   @OP: What MP3 encoder, and what settings were used...   Nov 17 2011, 15:10
|- - agatha1   QUOTE (mixminus1 @ Nov 17 2011, 15:10) @O...   Nov 17 2011, 15:43
- - Northpack   You should compare 320kbps MP3 with variable bitra...   Nov 17 2011, 15:11
|- - db1989   QUOTE (Northpack @ Nov 17 2011, 14:11) Yo...   Nov 18 2011, 11:38
- - pdq   Yes, you should never disable highpass as quality ...   Nov 17 2011, 16:51
|- - agatha1   QUOTE (pdq @ Nov 17 2011, 16:51) Yes, you...   Nov 17 2011, 20:13
|- - kwanbis   QUOTE (agatha1 @ Nov 17 2011, 19:13) Can ...   Nov 17 2011, 22:10
|- - Soap   Let's fix the terminology here. I think it is...   Nov 17 2011, 22:28
- - pdq   Converting from one compressed format to another i...   Nov 17 2011, 20:30
- - astroidmist   Hard drive space is always getting cheaper (except...   Nov 18 2011, 00:34
- - agatha1   Thank you all for your answers. The thread is bec...   Nov 18 2011, 01:34
|- - kwanbis   If all lossless formats are what they claim, i.e.,...   Nov 18 2011, 04:00
- - pdq   All lossless formats are identical in quality. Whe...   Nov 18 2011, 04:07
- - Glenn Gundlach   I don't know what hard drives go for in Spain ...   Nov 18 2011, 05:35
- - agatha1   * For Glenn Guldlach and astroidmist: I agree wit...   Nov 18 2011, 11:40
|- - kwanbis   QUOTE (agatha1 @ Nov 18 2011, 10:40) Howe...   Nov 18 2011, 17:22
|- - greynol   QUOTE (agatha1 @ Nov 18 2011, 02:40) I...   Nov 18 2011, 19:02
|- - kotekzot   QUOTE (agatha1 @ Nov 18 2011, 14:40) I ag...   Dec 26 2011, 20:12
- - pdq   Indeed it is possible for a defect in hearing to m...   Nov 18 2011, 12:54
|- - Remedial Sound   QUOTE (pdq @ Nov 18 2011, 06:54) Indeed i...   Nov 18 2011, 17:50
- - db1989   And it would still be helpful to post the logs of ...   Nov 18 2011, 13:01
- - agatha1   Hello everyone again. I've been quite busy set...   Dec 1 2011, 06:09
- - halb27   Encoding with 256 kbps is so good that chance is c...   Dec 1 2011, 09:19


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