Three forms of distortion:
1. Bad x fer at press plant. I have sent totally nice product to the press plant..one off was fine as proof. Glass mastering got screwed up..20K units that has nastyness.
2. High output (running 0dB/rms of -10) is too much for the consumer machines playback line out. It spews distortion. I master at a conservative level that does not allow machine (consumer) line out overload. My mastering played on FM is plenty loud..if not louder than the pushed up stuff.
3. Gain management, (mastering) not compensating for the cd. Inexperienced staff doing it without having lived the realum. It will be more wide spread.
Listen to headphone out of CDP. If it is nasty at moderate vol..then 1 or all 3 (Previals) are the culpret.