5) When it comes to 5.1 or 7.1, why is it that these aren't also considered lossy, since they are also a type of digital format?
Digital does not equal lossy.
Technically CD (Compact Disc) is a lossy medium because there is some information lost when the original performance (which is obviously analog as it occurs in the real world) is converted to CD. The sampling rate (number of "slices" of information per second) is high enough to where most people today consider it lossless. But that's why there is a niche market for SACD (Super Audio Compact Disc) which is a CD made from the analog masters but at a much higher sampling rate. Many audiophiles swear they can hear the difference, and I believe that most of them are full of shit, but I also believe that some people can actually hear it. Some people do have extraordinary hearing, and if they are also into music, it makes perfect sense.
Purists always point to vinyl as the ultimate lossless medium, because unless the album went through a digital mastering or mixing phase, no information has been lost due to digital sampling. This is becoming more and more rare, however, because even if the album is released on vinyl, there's a good chance that the mastering was done on modern digital equipment anyway. The sampling rates are generally so high nowadays that they're considered lossless to everyone except the hardcore purists.
Anyway, why aren't 5.1 or 7.1 considered lossy? Because 5.1 and 7.1 denote how many channels of sound you're talking about, not the medium or encoding process. Saying something is 5.1 versus 2.0 is the same as saying it's stereo versus mono. Either could be lossy or lossless. You're only talking about the number of channels.
If you have a movie on DVD with a 5.1 soundtrack, all that means is that you have front left, center and right channels, left and right surrounds (that's five so far) plus a low-frequency channel fed to your subwoofer (that's the .1). 7.1 is similar except that you have discrete side and rear surround channels, more like in an actual movie theater.
This is a separate issue from whether the soundtrack itself is lossy or lossless. The DVD specification does not allow for enough room to store true lossless soundtracks in 5.1. Dolby Digital 5.1 or DTS 5.1 sound pretty good to my ears, but they are not lossless.
Dolby TrueHD is a lossless codec, as is DTS HDMA (Hi-Def Master Audio). That's why it's a big deal (for now anyway) when a Blu-ray disc has TrueHD or HDMA. Blu-ray
does allow for lossless soundtracks. As with the WinRAR analogy given above, the soundtrack is digitized, but no information is lost, and upon decoding, the result is a lossless soundtrack. Again, "lossless" in this context only means that no information has been lost relative to the original soundtrack. Whatever process when into creating the soundtrack itself is not considered.
Topic: Confused with technological terms used to describe how music is stored (ex. mp3) (Read 6288 times)