iPod 128kbps: AAC or MP3

[donga]

You should be doing it "right" and use ALAC (or FLAC). Then you would never have to do it again. Now you have to look forward to re ripping again.

those would be huge files. maybe just use the original wav files from the cd, no compression at all! (except of course, they are already compressed from the original masters....)

it could go on and on and on... i guess it really just depends on personal preference, what you can tolerate, etc.

 

[MagnusVonMagnum]

I don't like Classical, but it doesn't work very well at all when compressed, because the dynamic range means the soft parts are pushed down into the quantization noise floor. I detest the analog/vinyl elitists, but we can't

I'm quoting this part first since it seems to be so relevant. You don't seem to knowing the difference between data compression and loudness compression. Loudness compression (the thing that kills the noise floor and makes everything LOUD) is something used by radio stations and mastering engineers (who are told to make things LOUD). Data compression is used to make file sizes smaller. It has no effect on frequency response itself. Rather, by removing information at lower bit-rates, the effects (air, warble, odd sounding cymbals, etc.), it is the wave form envelope that is corrupted, not the actual frequency response. At higher bit-rates, the differences are negligible and therefore inaudible (this starts to occur somewhere around 192kbps for AAC with absolute inaudibility at 256kbps and 256 for MP3 with absolute inaudibility at 320kbps).

Well, just keep telling yourself that. Lots of people do, but I'm afraid they are all wrong. There is still a huge difference between even 256 kbps compressed AAC quality and uncompressed CD quality. Bass is either muddy or mostly MIA, cymbals are swishy, separation suffers, and stereo imaging is "undefined", to put it diplomatically.

I've got a high-end system that would make most people's head swim in these forums and this blatant nonsense about 256kbps AAC having weak bass and swishing noises is just that. Nonsense. I've done ABX double-blind testing with 256kbps AAC and ALAC encodes of CDs and the differences are completely inaudible. Now if you start converting AAC to MP3, you will start creating audible problems since like succeeding tape generations, the loss of information will start piling up well into the audible spectrum. Convert once from lossless formats only whenever possible.

I'm also a musician on the side and record my music (at 24-bits for headroom) and it's the same thing. The 256kbps AAC versions sound identical to the 16-bit WAV ones. And don't tell me there's a loss of bass. That's simply untrue. I've got flat response to 25Hz on my home theater and 27Hz on my ribbon speaker stereo room setup. I've got bass coming out my hind quarter here and in the car and nothing is missing nor should it be. Nyquist (sampling rate) determines frequency response, not data compression. Don't confuse loudness compression with data compression.