Is there a way to tell if a music CD-R was copied from original CD (full audio quality) or if it was created using mp3s -> CD format (lower audio quality)?
Not really. Incorrect track lengths would be your best shot.
It’s possible you might be able to display compression artifacts in an equalizer graph, but I doubt they would be readily audible.
Would you be able to tell if you got a copy of the original CD, ripped that at say 320, and rip the questionable CD-R at 320 as well? Maybe lossless would work as well. If the file sizes are different, or the quality of one is noticeably degraded, that might be a clue.
I checked this out when I wanted to post some sound samples online for people to compare MP3 to CD (obviously uncompressing the MP3s first). I wanted to make sure you couldn’t cheat by inspecting the files.
I found that if you open the files in something like Audacity and look at the frequency spectrum or whatever it’s called, there’s an obvious cut-off in compressed audio somewhere between 12KHz and 15KHz, whereas uncompressed audio goes all the way up to about 20KHz.
This did the trick. Thanks.
There is a tool called Audiochecker, which is helpful but not 100%.
You can also use CueTools. This way you can take your rip and compare it to others who have rippped the same CD and compare results.
Of course this will only work if the CD has been ripped and submitted to the AccuRip database.