The Forum Killed Arkay wrote:
jimmyzen wrote:
... Having worked with electronics and computers my entire career I saw and understood the technical data on mp3 and knew it was bull pucky to even suggest it sounded the same. Most people don't have good hearing so they can't always tell or like I said earlier, if that's all you have to go by, an iPod sounds pretty good. But, alas the audiophie world is full of snake oil and charm bracelets, magic potions and alchemic substances. It's a greater stretcher of the truth than professional wrestling and a certain news channel that rhymes with box...
I'm an audio guy who has been out of the game for a while. My education in terms of audio is still pre-iPod. I think in terms of noise floor, headroom etc, which don't always line up with mp3s. In short, better or worse don't really work for me when I think of mp3 quality. The best I can come up with is confusing. If I hear a piece of audio pre-mp3, I can analyze it all kinds of ways and make reasonably accurate guesses as to how it has been processed. But, with mp3s, there is so much compansion and mystery processing that its hard to tell what is going on, even on pieces of audio that I know well. If you have some technical data on mp3s of various types that I can link to, that would be great. Anything to do with signal chain, AAC, tone, ipod normalization, or any processing info would be great. I used to strive for a 1:1 ratio of unity gain throughput, meaning that I am able to listen as closely to the source recording as possible. Now that mp3s screw with that so much, I rarely have any idea what the original recording was like. I'd like to learn what differences mp3s make to sounds outside of what most people say such as higher bit rate = good, or that mp3s tend to sound brittle on the high end and boopy on the low.
Many years ago there was a magazine called Stereo Review before they dropped the stereo part and started covering home theater, turned to a waste of reading time and maybe disappeared. I stopped reading it because I was and am a committed music separatist believing in a dedicated audio listening system. Towards the end of their publication run as Stereo Review, one of their writers did an article on mp3 that to this day was the best one I ever read. Besides the tech side with all the attendant charts and graphs, expanded wave forms, the author wrote as a music lover. The thing in the article that immediately got my attention was that the philosophy of mp3 was that music contained information that could be stripped away with minimal effect to the music listening experience. That was and is heresy to me. Admittedly it can be more obvious depending on what type of music you are listening to- a 3 piece power trio may sound OK where a string quartet or orchestra will not sound quite right in a way difficult to explain. My thinking about excess information in music goes like this: they start with removing harmonics. since harmonics have multiples covering a range removing them has a broader effect than just chopping off the one frequency. Harmonics are an integral part of any musical instruments sound character and they help establish its presence when playing with other instruments as well as facilitate the way certain sound and tones blend or work off each other. Start stripping them away and it has to affect the sound. Even with a well written compression logarithm, music is so variable that it doesn't seem possible that compressing and then decompressing is going to reproduce what was there originally. Even file size comparing mp3 to precessed FLAC files, to WAV, or other audio files clearly shows something is missing. The argument can be made even digital has it's draw backs. Consider a sine wave. The digital reproduction of it follows the contour but is like a set of stairs that simulate the analog signal. The analog signal will continue to rise, say, but does it continuously. The digital signal mimics this by rising to a certain level, flattening off, rising again, level off again, and repeat. What digital does is put such a large number of steps in that it becomes very close to the analog equivalent. But if you imagine stretching a carpet over the stairs tightly so it's smooth, the fact is the space between the flat spot of the stair to the underside of the stretched carpet is missing information. The more steps you put in though, the less missing information there is. Extremely simplistic explanation, but it helps visualize what goes on with digital vs analog and the basis for much of why there is a perceived sound difference between the two and why people argue about them. But back to mp3- part of the gamble and payoff about it is that human hearing, supposedly 20 to 20 KHz, seldom has the ability to hear that wide a spectrum even if it's a range that playback equipment can reproduce. As we age (dammit!) we lose the ability to hear well in certain frequency ranges naturally. It's wider if you have loud hobbies or work in a noisy environment. (An aside- I read a study that said wind noise generated in crash helmets worn by motorcyclists is detrimental to hearing. Barring wearing a full face helmet, it was recommended to wear ear plugs with an open helmet.) So, with mp3, we have audio content removed because it was deemed unnecessary to the reproduction of the audio information, what's there gets smashed down to make it small, and then it gets cookie cutter reproduced to be heard by people with less than perfect hearing over often less than ideal equipment. Throw in if it's background music or an intense listening session and that's even more variables. This may not be the best comparison, but if I take a piece of music I am familiar with, do a WAVE conversion of an mp3 version of it, burn it to CD and then play it over my sound system, it sounds worse, relatively speaking, than the same track played from the original CD. Again, admittedly, some pieces are more noticeable than others, but it's there. I found it ironic when I saw some very high end and super expensive straight class A amplified mp3 player docking stations. Don't get me wrong, I used my mp3 player a lot but most of the time I copied stuff into it in WAVE format.