This is a little test I made up because of a discussion that came up in this thread:
http://www.homerecording.com/bbs/showthread.php?s=&threadid=82429
http://www.astrondelta.com/charger/audio/mp3test/
I ripped 19 seconds of the song "mon enfant" from the Ralph towner album Diary (ECM, 1974). I chose this album for its dynamic source material, high frequency content, and liberal tape hiss (one of the most obvious places where MP3 artifacts show up). Using Pro Tools LE on Windows, I created 2 sessions, one @ 16-bit and one @ 24 bit. I imported copies of the stereo file into each session separately. In the 16-bit session, I used Waves' L1+ Ultramaximizer to boost the level by 3.4dB, while limiting to -0.1dB. In the 24 bit session, I used Waves' L2 to boost the level 3.4db while limiting to -0.1dB. In both sessions, I dithered the output with Dither Type 2 on the Ultra setting (you still have to dither from Pro Tools in a 16-bit session, because the output is always 24 bit from the Pro Tools mixer). I then bounced these files down to separate stereo wav files @ 16 bit.
Then I compressed these wav files to MP3, using LAME encoder version 1.30, engine 3.92 MMX. I set the VBR to level 3, with a minimum of 32 kbps, and a maximum of 320 kbps. I converted these MP3 files back to wav using Winamp. I then encoded two more MP3 files, using the same settings, from these wav files. These result files were also converted to wav files. For the 4 MP3 files I created, the sizes ranged between 384-392 k. The wav files all come out to 3.25 MB.
MP3 test: challenge
See if you can identify them correctly... of the 6 wav files listed below:
1 was a 24-bit wav, dithered to 16 using L2
1 was a 16-bit wav, dithered using L1
2 were MP3s of the above (wav > MP3)
2 were 2nd-generation MP3s of the above (wav > MP3 > wav > MP3)
test1
test2
test3
test4
test5
test6
http://www.homerecording.com/bbs/showthread.php?s=&threadid=82429
http://www.astrondelta.com/charger/audio/mp3test/
I ripped 19 seconds of the song "mon enfant" from the Ralph towner album Diary (ECM, 1974). I chose this album for its dynamic source material, high frequency content, and liberal tape hiss (one of the most obvious places where MP3 artifacts show up). Using Pro Tools LE on Windows, I created 2 sessions, one @ 16-bit and one @ 24 bit. I imported copies of the stereo file into each session separately. In the 16-bit session, I used Waves' L1+ Ultramaximizer to boost the level by 3.4dB, while limiting to -0.1dB. In the 24 bit session, I used Waves' L2 to boost the level 3.4db while limiting to -0.1dB. In both sessions, I dithered the output with Dither Type 2 on the Ultra setting (you still have to dither from Pro Tools in a 16-bit session, because the output is always 24 bit from the Pro Tools mixer). I then bounced these files down to separate stereo wav files @ 16 bit.
Then I compressed these wav files to MP3, using LAME encoder version 1.30, engine 3.92 MMX. I set the VBR to level 3, with a minimum of 32 kbps, and a maximum of 320 kbps. I converted these MP3 files back to wav using Winamp. I then encoded two more MP3 files, using the same settings, from these wav files. These result files were also converted to wav files. For the 4 MP3 files I created, the sizes ranged between 384-392 k. The wav files all come out to 3.25 MB.
MP3 test: challenge
See if you can identify them correctly... of the 6 wav files listed below:
1 was a 24-bit wav, dithered to 16 using L2
1 was a 16-bit wav, dithered using L1
2 were MP3s of the above (wav > MP3)
2 were 2nd-generation MP3s of the above (wav > MP3 > wav > MP3)
test1
test2
test3
test4
test5
test6