regalma1 wrote: > If I can't hear the difference then I won't bother. Its really not the file format that is critical. Cars are simply noisy and have terrible acoustics. You rapidly reach the point of diminishing returns.
There is a high end Lexus with a serious stereo (I think Mark Levinson) that is audiophile quality, but as soon as you put it in gear, you aren't going to hear it. Simple numbers, a quiet car at highway speeds generates 60 to 70 dB of noise. A RedBook CD has 96 dB of signal to noise. Adding 60 dB to 96dB takes you to 156 dB, which is way past where your ears fall out of your head. Anything over 120 dB causes permanent hearing damage.... A lot of rock/pop has much less than the theoretical max of 96 dB of range, as they are compressed to death as part of the loudness wars. > The thing I don't understand is why lossless files are so large. My > math suggests that they should be run at about 350 kbits/sec. The CD > sample rate is 44100 hz. The sample size is 16 bits. That comes out to > be 705.600 kbits/sec. 50% compression would reduce that to 353 > kbits/sec. > This seems to check. By my calculations the compressed file that runs > at 705 kbits/sec for 72 minutes would be about 381 MB, or about half a > CD's capacity. As I understand it, only about half the information on > the CD is music. The rest is for tracking, text, video and various > other things. None of which is needed for computerized playback. I must > be missing something here. Your math is off. And your basic assumption is incorrect. See http://www.pfarrell.com/prc/bits.html for some basics. On most RedBook CDs, the music is more like 99% of the data. RedBook audio is PCM @ 44.1kHz stereo two channels, 16 bit samples. This totals to = 172 Kbytes/second. Convert to bits and you get about 1.5 Megabites per second. Granted, a lot of pop/rock/country CDs have much less than the max, but a lot of classical CDs have more than 600 mbytes of music data. Lossless audio compressors get about 50% compression, or two to one. So a 600 MB CD will be 300 MB in Flac or apple lossless, etc. There are tiny differences between the various lossless codecs, but nothing that is important, a few percent here or there, which gets lost in any estimating effort. -- Pat http://www.pfarrell.com/music/slimserver/slimsoftware.html _______________________________________________ audiophiles mailing list [email protected] http://lists.slimdevices.com/lists/listinfo/audiophiles
