Also removed were noises, distortion, hiss, stick click count-ins, and any non-cleared or copyrighted samples (sounds or quotes taken from movies or television shows). That last part is shitty, I know - but there's no way I'm going through that kind of legal hassle ever again!
Some songs were professionally processed to dramatically improve sound quality. The process may have included any or all of the following: Dynamic enhancement, Transparent Limiting, Stereo width expansion, Dynamic EQ, "Tube" warmth, and various Harmonic enhancements....Overall, mastering for sound quality was only applied to the less "professional" sounding recordings in order to make them sound more like the big professional recordings. It is truly amazing what a difference this can make!
The International Punk Rock Box Set has been carefully put together to sound as good as possible and to make it "easy" for radio programming - all 10 discs meet broadcast standards etc.