Stereo or Joint Stereo? 44100 or 48000?

Originally Posted by Iceboy

192k is certainly not as good as it gets. I had a rip of a score in 192k and played it almost every day for a long time. I got used to it and thought it sounded great. I then got the CD and did a re-rip using API. WOW. What a difference! A much better, clearly, fuller sound with more high-end and less artefacts.

192k still cuts off a lot of high end. If it was "as good as it gets", higher bitrate encoding wouldnt have been invented!

This could be for many reasons. Rips that you don't do yourself (or that don't have files documenting the settings of the rip) aren't worth basing conclusions off of because:

1) it could be using an old, crappy quality encoder. Blade or Xing, anyone? Good thing mostly no one uses these things anymore.
2) some people got the brilliant idea to re-encode 128Kbps MP3s in a higher bitrate (rather than encoding from the original CD audio), erroneously thinking that it would increase the quality.

Also, I would warn that the psychological effects of seeing -- or just knowing -- that one file has a higher bitrate can influence your opinion about which sounds better. Many people claim to be able to hear a difference between MP3s of different high bitrates, but when they are played audio without knowing the bitrates of each they suddenly are unable to perceive any audible difference between the two.

Jam it back in, in the dark.

Guys, this argument really isn't necessary, and it's getting a little too fanatic. MP3 encoding is not about absolutes, its all approximation.

ArrowHead, of course encoding in VBR takes longer than CBR. The greatest power of a good VBR algorithm is that, for each frame, it tries to determine the best number of bits to represent that short segment with audible accuracy. And that determination is probably somewhat calculation-heavy, taking additional processor time. CBR simply doesn't need such a step since it already knows how many bits will be used. It's also Iceboy's choice whether he wishes to sacrifice disk space for quicker encode times, despite the fact that you only encode audio once. Maybe he has a whole lot to rip!

And Iceboy, I just want to correct what you're stating... most audio does not in fact "need" anywhere near 320Kbps to sound exactly the same as the original, to the typical human ear. That last bit is most critical: to the typical human ear. Even 320Kbps MP3s remove many frequencies from the audio, based on the idiosyncrasies of human hearing (known collectively as 'psychoacoustics') : one simple property being that a louder, lower frequency can make a simultaneously-played quieter, higher frequency completely inaudible!

The fact is that much of a waveform is completely unnecessary when your only concern is human perception, and lossy codecs take advantage of this. Over in the Hydrogen Audio forums, where many digital audio enthusiasts, audiophiles, and codec developers reside, one recurring theme highlights the over-sufficiency of 320Kbps. Whenever folks have tried to organize a community ABX-double-blind test comparing each format's best encoders at any bitrate higher than 128Kbps, they have a very hard time finding a significant number of people who can -- even under isolated listening conditions and repeated, focused listens -- verifiably rate the codecs against each other. There have been many instances of testers ranking the original audio below some of the compressed audio! 320Kbps is far from necessary to achieve audio that is no perceptibly different.

However, because the human hearing system is so complex and organic & because lossy audio encoders must use simpler algorithms that balance computing power/time vs. quality, certain so-called "killer" samples will cause evident flaws even at 320Kbps. Fortunately, such samples are usually uncommon. Their failure is usually less related to the bitrate used, and more related to the MP3 encoder not being 'tuned' to properly handle certain occurrences in audio. But it is certainly difficult to try to take into account the infinite number of ways audio can take shape, and LAME developers are continually refining the encoder against the latest "killer" samples. But yet it's still a sign that if you want to assure your music will always sound exactly the same as the original, you have to go with some totally lossless form of compression, such as FLAC (my preference) or Monkey's Audio. The disadvantage of this, however, is that while 320Kbps compresses to approximately 22.7% of the size of a CD-quality WAV, lossless codecs tend to range from 25-80%, typically more toward 60% or so.

Iceboy, it is entirely up to you whether you use 320Kbps MP3 or not; I cannot take issue with your choice. My only wish was to clarify your misperceptions, for you and and others who read this thread. I do wonder, though, if LAME's ABR mode encodes more quickly than the VBR presets, since I know encoding time was an issue for you...

Additional Post:

Originally Posted by Iceboy

As for the psychological effects, sure, I guess it happens. But when I did that 320k rip of that score, I knew it sounded better without hearing the old 192k rip. Instantly, I was impressed by its quality. It wasnt until I had played a few tracks that I went back to compare a couple and the differences were apparent.

The thing is these effects are not consciously felt, they are very subtle and subconscious. You can easily "hear" the 320Kbps songs as higher quality, because in your mind you know that 320Kbps is the highest setting possible, thus it ought to sound better. And as soon as sound hits your ear and passes, all you have left is a cursory mental impression, so you can't objectively take the sound and compare the full details side-by-side in your mind. Do more exploration into the subconscious power of mental suggestion... documented studies have been done on some really freaky effects. Nothing like ESP or superstitions or anything like that but... well, I'm kind of getting off-topic, so here's one interesting read on one aspect of the matter: http://www.quackwatch.org/01Quackery...ideomotor.html

It's also possible that those 192Kbps files -were- a bit crappy. I don't know if you said you encoded those with a recommended LAME encoder and settings, but LAME recently hasn't focused on CBR quality anyway, instead implementing good ABR and VBR and emphasizing their advantages. But I'd, for fun, challenge you to double-blind test yourself between those 192Kbps and 320Kbps samples with foobar2000's built-in ABX comparator (select two tracks -> right click -> Utils -> ABX two tracks). It's proven to me how easy it is to casually "hear" an improvement that, under examination, isn't really there. It's rather interesting.

There's nowhere I can't reach.

What we mean by more entropy or more noise is essentially audio with less of a pattern. Compression -- whether MP3, DivX, or ZIP -- utilizes the presence of predictable patterns to, in essence, remove redundancy and save space. However, as data approaches the purely random (entropy/chaos/"noise"), it gets more difficult to compress.

As for statistical data to show that anything less than 320Kbps is necessary... well, this isn't quite that, but it's a 128Kbps listening test conducted almost 3 years ago.
Test Introduction
Test Results
The participants are probably all self-professed audiophiles, since it was conducted on the HydrogenAudio.org forum. Double-blind tests were conducted with those formats vs. the original audio, and people were asked to rate the quality subjectively from 1.0 to 5.0, 5.0 being perfectly indistinguishable. Note how close some of these codecs are rated to 5.0 at just 128Kbps! So, it's certainly not improbable to think that bitrates above that could reach the level of being audibly indistinguishable. Although, I admit it would be wrong to decisively conclude that just from the results of this test.

This thing is sticky, and I don't like it. I don't appreciate it.