5/17/2002
DISCLAIMER: I am in no way slamming Rush! I just want to illustrate what many have found to be unacceptable audible distortions on the Vapor Trails CD.
For all of you non-believers here is some visual evidence of the clipping distortion on the Rush Vapor Trails CD. Below is a series of images of the wave data for “Secret Touch” pulled directly off the CD, along with a similar series for the Tool song “The Grudge” for comparison. These images are a small sample but are indicative of my entire CD.
Image 1 is a wave view of the song zoomed out so the entire song is visible. The scale on the vertical axis is given in samples, and since it’s 16-bit PCM the max is 32767 and the min is –32768.
Image 2 is a zoomed view of the highlighted section of Image 1, Image 3 zoomed from Image 2, and so on.
Secret Touch 4 shows clipping. No matter the sound system this will result in sonic distortion – whether or not you hear it is another thing. On my CD this distortion exists on all songs: in some cases it’s masked by the wall of music and comes across as a general “grittiness” and in less intense cases it stands out as “crackles”. I’m curious to know if all CDs are the same or if the clipping exists only on some - maybe batches manufactured at different foundries used bad masters?
Compare the Tool images one by one to the Rush images. Note that Image 1 for both indicates that there may be clipping, but the Secret Touch signal is obviously WAY hotter than the Tool. Yes, both songs are different and have different levels of intensity, but The Grudge has some very intense sections so it’s good enough of a comparison. The Grudge 1 is deceiving, though. Zooming further in you’ll notice that the signal does not clip… it gets close but it DOESN’T CLIP.
When I play The Grudge in my high-end car stereo I can set the volume to about 32/40 and the intense sections are on the verge of being way, WAY too loud. I get the same loudness on Secret Touch at about 25/40.
So, pictures don’t lie. Anybody who’s saying they hear distortion probably hears it because the raw data on their CD is flawed.
You can check out your own CD easily by ripping to a wave file (instead of MP3) using MusicMatch (http://www.musicmatch.com) and viewing it with CoolEdit (http://www.syntrillium.com, available as a free demo). Keep in mind that wave files take up about 10 Meg per minute on your disk.
The outer rim of the top of my VT CD has "Made in USA by WEA Manufacturing Inc. 83531-2", and on the backside inner rim it says "WEA Mfg. Olyphant X17594 3 83531-2 01 M1S7". Does anybody know if these are lot numbers? I'd be curious to know these numbers for those who have "clean" CDs and those who have "distorted" CDs.
I can't find a link for WEA directly but found lots of mentions in other links, namely that they are a division of the Warner Music Group.
One link shows more info that's probably found via ultra-violet. I don't have the right equipment so I can't illuminate it. This may be the actual lot info. Dunno.
