Digital music listening test!

[action9000]

I made up a little digital music test today.  The idea is simple:

[EDIT]: This test is a bit easier than I intended due to issues that Petrie pointed out to me regarding converting MP3 to MP3.  If you're interested in a more challenging listening test, I can make a new one.

I have CD-quality digital copies of these 6 songs on my computer.  I have compressed the 6 songs into MP3 files.  MP3 is a format where sound quality is decreased as it is compressed, so the more you compress it, the worse it sounds.

Some commonly used compression levels in MP3 files are:
320 kbps (kilobits per second)
128 kbps.

320 uses over twice as much data and results in a much higher file size.  It is also better sound quality....but can you tell the difference between 128 and 320?

How compressed is too compressed though?  It really depends on the individual.  That's where this test comes in.  

Two of the files for each song are exactly the same, at 128 kbps.  One file is a 320 kbps.  It is up to you to determine which one of the three is the high-quality 320!  There are 6 songs in total here so a perfect score is 6/6.  Can you hear the difference?  

Each song will have a choice of A, B or C as the 320 kbps version.  Pick the letter you think is the high-quality one.  Post here if you want the results and I will PM them to you.  Each track is from a slightly different musical genre.

By the way, don't bother using the file size or anything as a guide to cheating to find the right answer.  Every single one of these MP3s is a 320 kbps.  I compressed some of them to 128 kbps then back up to 320 kbps, leaving them at around 128 kbps for actual sound quality. B)

This may or may not be easy, depending how you normally listen to music.  I have checked the integrity of this test using software analysis and can prove that the 320 kbps files do have higher-quality sound than the 128 kbps files.  This isn't a fake test.

If you want this to be more challenging, Disable any visual effects your media player has.  Trust me.

Ready?  Here we go!

Live Orchestral, moderately loud, light
Track 1 - A
Track 1 - B
Track 1 - C

Live Orchestral, Loud, fast (you should recognize this track! )
Track 2 - A
Track 2 - B
Track 2 - C

Vocal, rock/orchestra, slow
Track 3 - A
Track 3 - B
Track 3 - C

Vocal, rock, choir/orchestra, epic
Track 4 - A
Track 4 - B
Track 4 - C

Pop/dance, faster
Track 5 - A
Track 5 - B
Track 5 - C

Virtual orchestra - soft to loud
Track 6 - A
Track 6 - B
Track 6 - C

Post a response if you've taken the test and you want the answers.  Comments are welcome but don't give away the answers please!

Bonus points to anyone who can name as many pieces above as possible!  I'll be shocked and amazed if anyone gets #6 though.    

[action9000]

Hmm, maybe I made this a bit too complex.  Seems Petrie's listening test took over.
This one is definitely tricker because there are the 3 choices instead of two.  I was trying to reduce the chance that people could simply guess the correct answer.

You don't have to check out all of the tracks. B)  I was just trying to throw some variety in.

[Petrie.]

Going from a 128kbps file to 320kbps file is a nasty transcode.  This would be too easy to pick out.

I picked one track (#3) and only had to listen to the first three seconds and could tell which one was the 320kbps track from the start.

If you really really want to confuse us do this:

CD -> mp3 (Lame -V5  ~128kbps VBR) -> FLAC lossless (to mask filesize differences)

CD -> FLAC lossless

That would be much harder than a constant bitrate mp3 file.

[action9000]

And this is why I need new headphones (apparently an encoding theory lesson wouldn't hurt either! ).

Okay, if this test is too easy for many people, I'll make another one.  I deleted my source files so I'd have to make them all again to improve the accuracy of this test.  I may if there's enough interest.