Originally posted by: Darth Editous
Here's a comparison of the spectra of those two samples (the one from Moth3r's DVD and the one from the Definitive LD, scaled to match widths):

http://img14.imgspot.com/u/05/213/17/freq.gif

It looks to me like there's more going on than "simple" pitch shifting* - see how the spacing between sounds changes?

DE (*not an audio engineer)

ah, ok this what I mean when time stretching the audio information is taken and then sliced into much smaller incrememental pieces, indivdually stretched, then put together as a whole track again with the new duration. The time stretching algorithm analyses each segment working out how best and much to time stretch them in relation to the different frequency information of that slice and in relation to the other slices (see the link I posted above for a far better and techincal explanation). It doesnt just grab the front end and back end and pull it to the right length.

I have to hold my hand up and admit that I havent got the whole of Moth3rs ANH release, so can't comment if the whole soundtrack sounds like it had been time stretched when originally mastered to VHS, but I would wager that it had been looking at the graph Darth Editous has posted. This is also another good argument for people doing a PAL version to get the ORIGINAL PAL Audio from a PAL Laserdisc (maybe get it from the pan & scan UK LaserDisc release since these arent that hard to get hold of) I agree with the argument that the audio quality difference between VHS audio and LaserDisc audio is not very great, but problems like dodgy time/pitch shifting done back then, and problems like VHS tape warp/stretching caused by repeated play of the tape over time WILL effect the audio alot more.

pupil *

*nearly done my masters degree in sound design, but a little rusty on the theory as its been a while since I did any