First let me point out that I am not anti-CD. I simply want to point out that I have found audible clipping on many and that it is perhaps a source of the CD harshness.
This relates to my point here in the "When Bad is Good" thread concerning hard clipping with digital formats:
http://forum.stereophile.com/forum/showflat.php?Cat=0&Number=66833&an=0&page=1#Post66833
I have several CDs where some tracks sound fine, others so harsh during loud passages that I can't stand to listen to them. I confirmed that there was clipping in the digital data on a few of these CDs.
I had heard that Diana Krall had some technically excellent recordings, but heard issues with her "When I Look in Your Eyes" CD. Here are my notes concerning this CD:
This recording was puzzling to me, some things sound very good others particularly bad with an old 70s-80s analog tape sound. This old sound was on the horns, strings and so on, its the easily recognized sound of analog tape being driven too hard. Many engineers use this as compression but it also produces a lot of intermodulation distortion (IM). It imparts a glassy/glare or wirey quality to the sound. These older sounding tracks are also noisy and without listening real closely I think I hear Dolby breathing. Tracks 1, 6, and 12 sound particularly bad technically, but it's interesting that track 3 sounds very good. Several tracks sound harsh, I didn't think it was clipping (would they be so careless?) at first but finally concluded that it probably was. Here it is clipping on track 1 "Let's Face the Music and Dance", lots of IM distortion on this track also. Note that this is the digital data on the CD with no playback electronics involved. I believe the time is 1:07:
http://baselaudiolabs.googlepages.com/DK_trk1_4.jpg
More: http://baselaudiolabs.googlepages.com/DK_trk1_3.jpg
This sounds like sibilance and might have clipped at an earlier point in the recording chain. The signal also hits the digital limit also as shown here by the white line cursor:
http://baselaudiolabs.googlepages.com/DK_trk1_1.jpg
Another: Carol King, "The Carnegie Hall Concert" June 18, 1971
My notes:
I'd listen and think nice live recording at Carnegie Hall, but it sounds like there's clipping, harsh and raspy sounding during the peaks, good most of the time but blatant clipping like harshness during peaks. The clipping was obvious to me because I know what it sounds like and heard it many times before in amplifiers when I had a scope on the output. I'm just using this as one of many examples of poor recording quality, there are many, many others. The recording is Carol King, "The Carnegie Hall Concert" June 18, 1971, track 15, this clipping problem is on most of the tracks. Time: 4:47 the first one is even rail to rail, its usually on the positive peaks for some reason on this recording. It looks to be in the digital domain because it's perfectly flat and at the digital maximum, I'm not blaming the digital process just pointing out that it's being misused. Clipping is something that must be avoided with digital formats, since this distortion is an abrupt, hard nonlinearity. Digital formats do not soft limit/compress like many analog formats which however causes other issues:
http://baselaudiolabs.googlepages.com/TRK15_4_47B.jpg
A closer view:
http://baselaudiolabs.googlepages.com/TRK15_4_47.jpg
And a few more here at 5:04:
http://baselaudiolabs.googlepages.com/TRK15_5_04.jpg
I do not mean to suggest that analog is better, but perhaps recording engineers need to be made aware of the careful use of limiting/compression particularly with digital formats.
First let me point out that I am not anti-CD. I simply want to point out that I have found audible clipping on many and that it is perhaps a source of the CD harshness.
This relates to my point here in the "When Bad is Good" thread concerning hard clipping with digital formats:
http://forum.stereophile.com/forum/showflat.php?Cat=0&Number=66833&an=0&page=1#Post66833
I have several CDs where some tracks sound fine, others so harsh during loud passages that I can't stand to listen to them. I confirmed that there was clipping in the digital data on a few of these CDs.
I had heard that Diana Krall had some technically excellent recordings, but heard issues with her "When I Look in Your Eyes" CD. Here are my notes concerning this CD:
This recording was puzzling to me, some things sound very good others particularly bad with an old 70s-80s analog tape sound. This old sound was on the horns, strings and so on, its the easily recognized sound of analog tape being driven too hard. Many engineers use this as compression but it also produces a lot of intermodulation distortion (IM). It imparts a glassy/glare or wirey quality to the sound. These older sounding tracks are also noisy and without listening real closely I think I hear Dolby breathing. Tracks 1, 6, and 12 sound particularly bad technically, but it's interesting that track 3 sounds very good. Several tracks sound harsh, I didn't think it was clipping (would they be so careless?) at first but finally concluded that it probably was. Here it is clipping on track 1 "Let's Face the Music and Dance", lots of IM distortion on this track also. Note that this is the digital data on the CD with no playback electronics involved. I believe the time is 1:07:
http://baselaudiolabs.googlepages.com/DK_trk1_4.jpg
More: http://baselaudiolabs.googlepages.com/DK_trk1_3.jpg
This sounds like sibilance and might have clipped at an earlier point in the recording chain. The signal also hits the digital limit also as shown here by the white line cursor:
http://baselaudiolabs.googlepages.com/DK_trk1_1.jpg
Another: Carol King, "The Carnegie Hall Concert" June 18, 1971
My notes:
I'd listen and think nice live recording at Carnegie Hall, but it sounds like there's clipping, harsh and raspy sounding during the peaks, good most of the time but blatant clipping like harshness during peaks. The clipping was obvious to me because I know what it sounds like and heard it many times before in amplifiers when I had a scope on the output. I'm just using this as one of many examples of poor recording quality, there are many, many others. The recording is Carol King, "The Carnegie Hall Concert" June 18, 1971, track 15, this clipping problem is on most of the tracks. Time: 4:47 the first one is even rail to rail, its usually on the positive peaks for some reason on this recording. It looks to be in the digital domain because it's perfectly flat and at the digital maximum, I'm not blaming the digital process just pointing out that it's being misused. Clipping is something that must be avoided with digital formats, since this distortion is an abrupt, hard nonlinearity. Digital formats do not soft limit/compress like many analog formats which however causes other issues:
http://baselaudiolabs.googlepages.com/TRK15_4_47B.jpg
A closer view:
http://baselaudiolabs.googlepages.com/TRK15_4_47.jpg
And a few more here at 5:04:
http://baselaudiolabs.googlepages.com/TRK15_5_04.jpg
I do not mean to suggest that analog is better, but perhaps recording engineers need to be made aware of the careful use of limiting/compression particularly with digital formats.