@Superrayman3, RU.08, ScruffyNerfHerder
Since some of you keep mentioning the LD, can you please be more specific about what LD release you mean? There are plenty different ones including the 1662 CS which according to DiscLord is supposed to have the unaltered far field mix as PCM.
However, your mentioning of 48kHz suggests AC3 as this is the only format on the LD which uses that sample rate.
@Superrayman3: Maybe you mean the content which might in fact be different fidelity-wise but just in case you were referring to the technical aspects in general, a few remarks as this is very often stated wrong:
I’d like to try doing the same with the optical track as well but that one may be a bit trickier to work with since it’d be at a much higher bitrate and have a higher fidelity in comparison to a CD which would probably make such an edit noticeable when compared to the LD track which has a similar bitrate and fidelity to a CD but I’m open to trying it if it means I can help preserve a piece of Disney history).
What do you mean by ‘higher bitrate’ in comparison to “a CD”? If you refer to sample rates and bitrates, there is good news or bad news (depending from the point of view): there is no “higher fidelity” than what the good old, soon getting 36, CD provides. At least not as long as human beings don’t develop better ears. Much better ones as actually, the CD specs already exceed them severely in most situations. Both the sample rate and the bit depth in PCM provide such high quality (in theory, we better don’t get into nowadays charts music) than there is not a single blind test which has proven any high resolution audio to be discernible from it’s “old-fashioned” CD counterpart (given the same mastering of course).
I just ran some basic tests using the LD audio and restoring the original line is somewhat possible but there’s two caveats at play, first the LD audio will have to be down-mixed from 48000 to 44100 in order to keep a consistent quality with the CD audio (from what I understand if my research is correct, the audio track on LDs was originally encoded at the 16-bit 44100 sample rate prior to the introduction of AC3 so theoretically there should be little to no noticeable quality loss if my understanding of LD audio is correct)
With nowadays software, the conversion of 48 kHz to 44.1 kHz should be completely transparent and these few kHz one loses on the Nyquist frequency, virtually no one can hear anyway. AC3 is technically worse than PCM of course given the same source, but even here … at 384 kBit/s maybe, I haven’t had a change to really ABX them. At least it shouldn’t be entirely impossible. 😃