# Identifying Music CD-R Source **URL:** \ **Category:** Factual Questions\ **Created:** [July 5, 2010, 6:49pm UTC](https://boards.straightdope.com/t/identifying-music-cd-r-source/545618 "2010-07-05T18:49:47Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![Hermitian](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hermitian/32/470_2.png) [@Hermitian](https://boards.straightdope.com/u/Hermitian)\ **Post date:** [July 5, 2010, 6:49pm UTC](https://boards.straightdope.com/t/identifying-music-cd-r-source/545618/1 "2010-07-05T18:49:47Z")
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)? ---
**Author:** ![Palooka](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/palooka/32/2902_2.png) [@Palooka](https://boards.straightdope.com/u/Palooka)\ **Post date:** [July 5, 2010, 7:02pm UTC](https://boards.straightdope.com/t/identifying-music-cd-r-source/545618/2 "2010-07-05T19:02:16Z")
Not really. Incorrect track lengths would be your best shot. ---
**Author:** ![Telperion](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/telperion/32/509_2.png) [@Telperion](https://boards.straightdope.com/u/Telperion)\ **Post date:** [July 5, 2010, 7:03pm UTC](https://boards.straightdope.com/t/identifying-music-cd-r-source/545618/3 "2010-07-05T19:03:20Z")
It’s possible you might be able to display compression artifacts in an equalizer graph, but I doubt they would be readily audible. ---
**Author:** ![thelurkinghorror](https://avatars.discourse-cdn.com/v4/letter/t/7c8e57/32.png) [@thelurkinghorror](https://boards.straightdope.com/u/thelurkinghorror)\ **Post date:** [July 5, 2010, 7:50pm UTC](https://boards.straightdope.com/t/identifying-music-cd-r-source/545618/4 "2010-07-05T19:50:44Z")
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. ---
**Author:** ![Ximenean](https://avatars.discourse-cdn.com/v4/letter/x/aca169/32.png) [@Ximenean](https://boards.straightdope.com/u/Ximenean)\ **Post date:** [July 5, 2010, 7:51pm UTC](https://boards.straightdope.com/t/identifying-music-cd-r-source/545618/5 "2010-07-05T19:51:35Z")
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. ---
**Author:** ![Hermitian](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hermitian/32/470_2.png) [@Hermitian](https://boards.straightdope.com/u/Hermitian)\ **Post date:** [July 5, 2010, 8:09pm UTC](https://boards.straightdope.com/t/identifying-music-cd-r-source/545618/6 "2010-07-05T20:09:47Z")
> [@Ximenean](#): > > 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. ---
**Author:** ![Markxxx](https://avatars.discourse-cdn.com/v4/letter/m/5daacb/32.png) [@Markxxx](https://boards.straightdope.com/u/Markxxx)\ **Post date:** [July 6, 2010, 4:38am UTC](https://boards.straightdope.com/t/identifying-music-cd-r-source/545618/7 "2010-07-06T04:38:04Z")
There is a tool called [Audiochecker](http://www.dester.hu/English/home_e.html), which is helpful but not 100%. You can also use [CueTools](http://wiki.hydrogenaudio.org/index.php?title=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.