A procedure for ABX and objective listening

patate91

Well-Known Member
ABX and objective listening

I would like to share with you a way to train your ears with different music quality files and to compare equipments*, mixing techniques* as well as undesired effects like clipping.

*I still need to source or produce those files. Help is welcome since I'll have to learn how to do it. I'll update this thread as soon as I can. Note that I have access to music files with the owner's agreement.


With the right tools and knowledge we could hope to have more quality music and gear.

You can first practise your ears with your computer and heaphone. With your speakers and complete system, you will have to deal with the acoustic properties of your room. Once your ears get used to hear what you want switch with your speakers. Please share your experiences with gear swapping and the impact with your results.

If you own the proper equipement you can record your gear : preamplifier, amplifier, cables, DAC, sound cards, etc. and share your files. It could help members to get an idea on what they want to buy. Also It could be a good idea to build a database for comparison purpose.*

*Help here is welcome, to build a procedure or for file sourcing

Feel free to add content and correct me if needed. This procedure can be copy, reuse and modify at will, share it with your friends.


What you will need to do your tests :

  • A computer or a laptop(more convenient).
  • Foobar2000 + Converter pack plugin + ABX comparator plugin
  • A high quality music file, like FLAC. Make sure your DAC fully support it. (You can rip it from a CD you own : https://www.cnet.com/how-to/how-to-rip-your-music-cds-to-flac/ ) *Even easier with foobar2000)
  • A usb DAC with a usb cable long enough to get to your computer
or
  • An RCA to audio jack
temium_rca_mini_jack_3_5mm_.jpg
  • A preamplifier/ amplifier
  • Headphone and/or speakers
  • An open mind
  • A friend can be useful for testing with speakers if your cables are not long enough to get to your sweet spot.
You can get music files here
https://www.mediafire.com/folder/sm2clux7472z6/Music_files

See post #5 for more music samples

Note that I'll attached the procedure to this thread in case pictures are no longer hosted. Please rename the file ABX procedure 1.2.docx
 

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Installation procedures

1- In order to do your tests you will need to download Foobar2000 and install it on your computer.

You can find it here : http://www.foobar2000.org/download


2 - For this exemple we will compare the same file with a different quality and bit rate. so you will have to donwload the Foobar2000's converter pack plugin.

You can find it here : http://www.foobar2000.org/encoderpack

Once downloaded, you have to install it.


3 - To compare files you will need the Foobar2000's ABX comparator plugin

You can find it here : http://www.foobar2000.org/components/view/foo_abx

Here's the procedure to install it :

Step 1: Open the foobar2000 preferences dialog (click File | Preferences or key CTRL+P).
Foobar - Preferences.png
Step 2: Go to the Components page.

Step 3: Click the "Install..." button and select the component archive, or simply drag it to the list.
Foobar - Install.png
Foobar - Install - 2.png
Step 4: Press "OK", you will be prompted to restart foobar2000 in order to load the newly installed component.
 
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Converting process

You will need a high quality music file (make sure your DAC fully support it), you can use a file you have downloaded from a legal source or rip it from one of your CD. https://www.cnet.com/how-to/how-to-rip-your-music-cds-to-flac/

  • Open Foobar2000
  • Click File -> Open -> Choose your music file
  • Right Click on the file in the playlist menu -> Go to Convert -> Go to ''...'' and click on it
Foobar -  Click Convert.png

The Converter steup window will appear with four menus.
Foobar  - Converter Setup.png

1 - Outpout format
1.1 - Click on Output format -> Choose the output format you want and click Edit (for this exemple we will use MP3).
Foobar - Output Setting.png
1.2 - Set the quality you want - 130kbps here for our earing test -> Click OK
Foobar - Quality Setting.png
1.3 - Click Back


2 - Destination

You can leave the default settings - Foobar will ask you where you want to save your file when the conversion will be done.


3 - Processing
Now we want to resample the file.

3.1 - Click on Processing
3.2 - Choose Resampler (DBpoweramp/SSRC) from the left menu and click on the arrow to load it to the right
Foobar - Processing menu.png
3.3 - Select it in the right menu and Click -> Configure selected
3.4 - Select the desired bit rate - let say 44100 Hz -> Click Ok
Foobar - Bit rate selection.png
3.5 - Click Back

4 - Other

You can leave this by default.

  • Click Convert
Foobar - Convert.png

  • A window will comes up showing the converting progress.
Foobar - Converting.png

  • Once finish close the output converter window
It's done!
 
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ABX Comparison

Comparing our files

  • Click File -> Open... -> Select both files you want to compare.
  • Make sure both file are selected in the playlist menu - Right Click on tracks -> Go to Utilities -> ABX tracks... and click on it.
Foobar - Choose - ABX.png
  • Choose the number of trials you want - Let say 10 for now -> Click Ok.
Foobar - ABX - number of trial.png

Let's have some fun and start comparing our files.

You can now play the A file and the B file, take your time here and try to identify which one is flac or 130kbps mp3.

Then play the X file and the Y file, you can go back and forth with the A and B file. (1)

  • Choose in the right menu if ''X is A, Y is B'' or ''Y is A, X is B''. (2)
  • Click Next trial. (3)
  • Start again.
Foobar - ABX - Listen and choose.png
  • Once all 10 tests are done click -> Finish
Foobar - ABX - Finish.png
  • You will now have your log file, you can now -> Save it and share your results here if you want.
Foobar - ABX - Save log.png

Voila!

Now train your ears and share your results here. There's no shame to fail to identify certain things, there's a lot of marketing hype and a lot of people who will make you doubt : if you never heard a X system that worth several thousands dollard you won't never know. Most gear today are transparent and the room's acoustic will have a huge impact on how your speakers sound.

Enjoy!:)
 
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Useful links

  • Need music files to experiment?
Artifacts and noise : http://ethanwiner.com/audibility.html
Converters (25$ sound card vs high price gear): http://ethanwiner.com/converters.html
24 bits vs 16 bits : http://ethanwiner.com/BitsTest.html
Dither vs truncation : http://ethanwiner.com/dither.html
Dither : www.sereneaudio.com/blog/what-does-jitter-sound-like
HydrogenAudio : https://hydrogenaud.io/index.php/board,35.0.html

  • Youtube video
Compression
Compressed vs uncompressed

Clipping
Digital vs Analogue

  • Others ways to train and test your ears
http://harmanhowtolisten.blogspot.ca/?m=1

  • Does your computer or music server will add noise?

https://archimago.blogspot.ca/2017/09/musings-evidence-of-digital-player.html?m=1

Opposing Links to Archimaho's measurements, note that those articles are from 2013 and 2016. Feel free to comment directly on his blog.
https://db.audioasylum.com/mhtml/m.html?forum=pcaudio&n=155193
https://db.audioasylum.com/mhtml/m.html?forum=pcaudio&n=124929

  • 24/192 + music files

https://people.xiph.org/~xiphmont/demo/neil-young.html

Ask me if you have suggestions and I'll add them. Particularly links to different approach and way of thinking.
 
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Unfortunately, that presumes one uses a general purpose computer for playback.

I do only for the office system using $12 in wall speakers. I try to isolate the server as far from the music systems as possible. :)
 
Unfortunately, that presumes one uses a general purpose computer for playback.

I do only for the office system using $12 in wall speakers. I try to isolate the server as far from the music systems as possible. :)

Laptop has batteries, so no fear of adding noise if you think it will. Maybe one day you'll be able to experiment at a frien's house.
 
As you can see the tests can ne done directly on a computer. Testing on your system could be use to see how revealing it is.
 
But "AC borne noise" is really just trying to "not participate".
Here is the computer you'll find in my listening room. The John Swenson designed microRendu is a headless player running a very light version of Linux optimized for music playback. It's powered by his LPS-1 and incorporates the Regen USB circuitry. Connectivity to server located on the floor below is via 50' CAT7 ethernet.

urendu_sm.jpg
 
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Why are you using a Raspberry pi, as far as I know it's a computer?
Like the uRendu, the RPI used in the garage is a headless player using a declocked ARM processor running a thin, application specific version of Linux. Both are galvanically isolated from the i7-860 based server that functions as NAS for music (and video) storage.

rpi0917.jpg
 
@E-Stat

To remain constructives can you give me an exemple or point me to specific songs that I can have and share here to practice our ears in subtle or night and day changes.
 
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To remain constructive can you give me an example or point me to specific songs that I can have and share here to practice our ears un subtle or night and day changes.
You're referencing the Faerie Sorcerer as a definitive source? On another board, real professionals have pointed out the limitations of his crude test gear. Simple jitter plots constitute parlor game conclusions.

Content? Anything with good resolution and wide dynamic range. Try the "He's Here for Us" track from the 96/24 soundtrack from Rogue One I used the in the "Videos of your system" thread.
 
Thanks for the song suggestion.

As far as I know there's no consensus on professional boards.

Sometime we have to remain constant : Trust your ears and listen to music, but don't trust your ears if it's an ABX ou Blind Test.
 
@E-Stat feel free to send me links to oppose the links I'll add. I think everyone will benefits to have a quick access to both sides of the coin
 
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