Lossless vs 320kbps vs 256kbps, Moderation: no actual ABX results to see here. Options

[agatha1]

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.

[db1989]

1. Moved to Listening Tests
2. Post test logs, please
3. Using one song, and especially one with a specific type of artefact, is not an accurate way to predict the performance of a particular format/setting on your entire library. Test various tracks, genres, etc.