After 4 Years, HydrogenAudio Opens New 128kbps Listening Test

kwanbis writes "After more than four years, a new MP3@128kbps listening test is finally open at HydrogenAudio.org! The featured encoders are: LAME 3.97, LAME 3.98.2, iTunes 8.0.1.11, Fraunhofer IIS mp3surround CL v1.5, and Helix v5.1 2005.08.09. The low anchor is l3enc 0.99a. The purpose of this test is to find out which popular MP3 VBR encoder outputs the best quality on bitrates around 128 kbps. All encoders experienced major or minor updates that should improve audio quality or encoding speed, and we have a totally new encoder on board. Note that you do not have to test all samples — it is a great help even if you test one or two. The test is scheduled to end on November 22nd, 2008."

Comments

What kind of music is involved

[CRCulver]

While popular music is acceptable at 128kbps with recent encoders, certain niche music genres like spectralist music clearly suffer at low bitrates. With pieces like Per Norgard's Symphony No. 3 or Grisey's Les espaces acoustiques you can easily hear the difference between 256kbps and the original CD-quality on even average headphones or speakers. Any music which depends on a greater portion of the natural overtone series than just the first handful of partials will need higher bitrate encoding.

Re:What kind of music is involved

[IceCreamGuy]

"Overtones" are not an issue

Incorrect. One of the ways MP3 achieves lower bitrates is by removing overtones of a fundamental frequency when the overtones are reasonably quieter. If, for example, you pluck an "A" string tuned to 440hz, the string would also resonate at 880Hz, 1320Hz, 1760, and so on. An MP3 encoder would remove these overtones if they were significantly quieter than the original 440Hz tone, since research has shown that the human ear doesn't really notice them if the fundamental is much louder. The problem arises, as the parent noted, in some niche music; however anyone should be able to notice this in things like cymbals, where the most basic sound and timbre of the instrument is defined entirely by the overtones it produces. You can hear this as an almost flanger-esque quality to the cymbals in sub-128Kb/s encoded MP3s. Any drummer will tell you that this drives them up a wall, and the way the psychoacoustic model of MP3 compression handles overtones is the culprit.

Re:ugh

[HateBreeder]

Agreed.
I went into the trouble of trying to run this under Linux.
the supplied batch files didn't work - it was missing files due to bad paths. the java application required a HUGE meddling around, choosing the settings, creating tests... I gave up. I'm not *that* motivated to help.

If you're trying to design a public test, the goal is to make it as simple as possible. An online application is an absolute must here.

I would be surprised if there will be anymore than a few hundred responses to this, all from a very specific demographic, Hardly a representative sample of the general population.