http://www.digital-recordings.com/cdcheck/cdcheck.html
anyone tried this ? how is it ?
Full Version: Anyone heard of or used CD-CHECK ?
It does indeed contain five levels, or error causing conditions, overlaying a test signal.
The first level is not externally added and is claimed to be simply the standard manufacturing condition, which as you probably know means a maximum 220 correctable error per second averaged over 10 seconds. If you hear problems here, you probably hear them with any and every CD.
The next four levels are externally added. There are black marks of varying widths painted over the surface. Untoward noises emerging during playing of the test tone means the player's error correction did not cope successfully. Their 'suggestion' is that a CD player that cannot recover from these may have deficiencies in design, construction, or alignment. In particular, it may be on its last legs or need maintenance.
CD players do indeed vary in their ability to correct these induced errors. I tested several. At one end, a player consistently had severe problems with the first paint mark area and at the other extreme a (different) player had mild problems with the fifth band. some, of course, fall between these extremes. I had no player available that completely passed the most extreme test.
The player that tested best was more than ten years old. The one that did worse was a fairly expensive, very recently purchased one. With music, it is rather difficult to do any legitimate A/B testing, but if there is any difference in the sound from the players, it is in favor of the one that tested worst.
Mild problems with music CDs may slip by unnoticed in casual listening, so who knows if there have been a few more uncorrectable errors? There has been only one occasion where the player that doesn't test well had a noticeable difficulty with a commercial CD. That problem definitely did not show up when the CD was played in another player but it also happened only intermittently, and not consistently at the exact same place in the music, on the poor testing player.
Probably the best use of the test CD, if it really has a good use, is to make a carefully record of test results. Perhaps even record it to computer so some objective analysis is possible. If test results are worse some day, the player may need attention.
However, the good sounding player that tests so poorly on band two doesn't have any room for test results deterioration. It already does so extremely poorly that the only way it could be worse is to produce band one problems. Since that is supposedly standard manufactured CD quality, any CD should do as well as this one for a test standard.
The first level is not externally added and is claimed to be simply the standard manufacturing condition, which as you probably know means a maximum 220 correctable error per second averaged over 10 seconds. If you hear problems here, you probably hear them with any and every CD.
The next four levels are externally added. There are black marks of varying widths painted over the surface. Untoward noises emerging during playing of the test tone means the player's error correction did not cope successfully. Their 'suggestion' is that a CD player that cannot recover from these may have deficiencies in design, construction, or alignment. In particular, it may be on its last legs or need maintenance.
CD players do indeed vary in their ability to correct these induced errors. I tested several. At one end, a player consistently had severe problems with the first paint mark area and at the other extreme a (different) player had mild problems with the fifth band. some, of course, fall between these extremes. I had no player available that completely passed the most extreme test.
The player that tested best was more than ten years old. The one that did worse was a fairly expensive, very recently purchased one. With music, it is rather difficult to do any legitimate A/B testing, but if there is any difference in the sound from the players, it is in favor of the one that tested worst.
Mild problems with music CDs may slip by unnoticed in casual listening, so who knows if there have been a few more uncorrectable errors? There has been only one occasion where the player that doesn't test well had a noticeable difficulty with a commercial CD. That problem definitely did not show up when the CD was played in another player but it also happened only intermittently, and not consistently at the exact same place in the music, on the poor testing player.
Probably the best use of the test CD, if it really has a good use, is to make a carefully record of test results. Perhaps even record it to computer so some objective analysis is possible. If test results are worse some day, the player may need attention.
However, the good sounding player that tests so poorly on band two doesn't have any room for test results deterioration. It already does so extremely poorly that the only way it could be worse is to produce band one problems. Since that is supposedly standard manufactured CD quality, any CD should do as well as this one for a test standard.
Just wondering... If you had a Disc T@2 burner, couldn't you burn the pattern on the data surface and afterwards write some audio tracks on the disc? Too bad Label Flash is available only for DVDs...
You must write the audio onto the disk first. These supposedly precise 'errors' are there to interfere with reading from the disk, not to prevent you from putting the tracks onto the disk in the first place.
This CD set me off on a search for good test CDs. Tests that are not just noise and tones but something that will give an idea of the quality/condition of the transport and dacs used in the CD player. I found these two. Many of you might already have them -
http://www.amazon.com/gp/product/samples/B...ing=UTF8#disc_1
http://www.amazon.com/gp/product/samples/B...ing=UTF8#disc_1 (linearity checks)
Any feedback/comments from anyone who has used these CDs would be highly appreciated. Any alternative recommendations or suggestions are welcome.
The CD-CHECK will cost me $55 incl.shipping. I might as well buy a soundcard that will allow me to record via a spdif connection and do a simple play->record->compare test, or by doing an EAC DAE Quality test. Although it would be quite handy when shopping for a new cd-player. And it has an advantage over the drop-out/error correction checks in the Pierre Verany CD that the PV has only a sine wave signal whereas the cd-check has a complex signal (well not as complex as music ofcourse but a 200hz and 22.05Khz mixed signal) which is more difficult to recreate than a simple sine wave.
http://www.amazon.com/gp/product/samples/B...ing=UTF8#disc_1
http://www.amazon.com/gp/product/samples/B...ing=UTF8#disc_1 (linearity checks)
Any feedback/comments from anyone who has used these CDs would be highly appreciated. Any alternative recommendations or suggestions are welcome.
The CD-CHECK will cost me $55 incl.shipping. I might as well buy a soundcard that will allow me to record via a spdif connection and do a simple play->record->compare test, or by doing an EAC DAE Quality test. Although it would be quite handy when shopping for a new cd-player. And it has an advantage over the drop-out/error correction checks in the Pierre Verany CD that the PV has only a sine wave signal whereas the cd-check has a complex signal (well not as complex as music ofcourse but a 200hz and 22.05Khz mixed signal) which is more difficult to recreate than a simple sine wave.
Maybe I am missing the point here, but Andre offers a method of making a DAE disc for testing drives. Does this not do the job you want?? 
I somehow get the impression that you just didn't believe my post. That CD will not tell you anything about how good the player sounds and it seems unlikely, from my experience, that it will tell you anything else except maybe how well the player will do with badly scratched CDs.
Since "how good a CD player sounds" is purely subjective I would posit that a CD of music might be best.
DAE test CD's are pretty objective, either it reads or it does not. I believe the poster's original question was about DAE, not quality of the sound. This is what Andre's CD tests as does the CD mentioned in the original request. What you say is quite interesting, though.
DAE test CD's are pretty objective, either it reads or it does not. I believe the poster's original question was about DAE, not quality of the sound. This is what Andre's CD tests as does the CD mentioned in the original request. What you say is quite interesting, though.
QUOTE
either it reads or it does not
But the CD-Check test only actually apply to highly atypical reading conditions. I don't believe it says anything about the player's ability with 'normal' CDs that haven't spent time as baby's toys.
Andy, I am sorry if I gave a wrong impression but actually I am indeed agreeing with your post. That's exactly why I said that Andre's eac test, or even simply recording a wav file of a track played on the cd-player and comparing it with a securely ripped wav file of the same track, would certainly give an idea - maybe even a better idea - about the dae quality of the player. Where I thought this CD would be useful was in a place where you cant just spontaneously do this type of testing - like in a store, and even that is not motivating enough for me to spend $55 right now.
Then I posted about the two other CDs for getting an idea of the guts of the player - not just dae quality. No, I wasnt in search for anything (let alone a CD) that will tell me what is the "sound quality" of a player. I always let my not-so-golden ears do the honours in this category. However, if I ever am in the market for a cd player I would certainly utilize both the CDs and my ears to make the final decision. By "quality" I didn't mean "sound quality" but the mechanical/electrical quality of the system. Although I am sure you will agree that the mech/elect quality will have an impact on the sound quality of the machine too. Hope this helps clear up a few things.
Then I posted about the two other CDs for getting an idea of the guts of the player - not just dae quality. No, I wasnt in search for anything (let alone a CD) that will tell me what is the "sound quality" of a player. I always let my not-so-golden ears do the honours in this category. However, if I ever am in the market for a cd player I would certainly utilize both the CDs and my ears to make the final decision. By "quality" I didn't mean "sound quality" but the mechanical/electrical quality of the system. Although I am sure you will agree that the mech/elect quality will have an impact on the sound quality of the machine too. Hope this helps clear up a few things.
QUOTE(goodsound @ Mar 29 2006, 12:10 PM)
. . . That's exactly why I said that Andre's eac test, or even simply recording a wav file of a track played on the cd-player and comparing it with a securely ripped wav file of the same track, would certainly give an idea - maybe even a better idea - about the dae quality of the player.
Maybe I am wrong here - there is a good chance - but doesn't EAC rip a bit-for-bit copy of the file on the CD. That is to say, an exact copy? That is the great part about Exact Audio Copy is that you get an exact audio copy of the original. It can be verified by CRC check or a bit-for-bit compare, can it not??
And if this is true, I believe it is, the original CD or the copy would be the same. Actually, the copy might be "better" in that the original could have been damaged and taken some time to get the "exact" copy ripped by EAC. So, the original and the copy would be the same except that the original might have surface damage which the new copy would not. So, the player would give you the same or possibly slightly better results from the copy because it would proabably not have surface damage.
Is this all making sense or am I in LaLa land here???
1. securely rip a track from an original audio CD. Better if the track is slightly damaged - enough not to make secure mode choke. (lets call this file Wav1)
2. play the same audio CD (ofcourse same track) in your cd player, feed the spdif out into the soundcard's spdif in and record a wav file.(make this Wav2)
3. now compare Wav1 and Wav2. Consider Wav1 as the "reference" copy.
Differences would mean that the player is loosing traction somewhere.
Makes sense ?
2. play the same audio CD (ofcourse same track) in your cd player, feed the spdif out into the soundcard's spdif in and record a wav file.(make this Wav2)
3. now compare Wav1 and Wav2. Consider Wav1 as the "reference" copy.
Differences would mean that the player is loosing traction somewhere.
Makes sense ?
QUOTE(goodsound @ Mar 29 2006, 03:02 PM)
1. securely rip a track from an original audio CD. Better if the track is slightly damaged - enough not to make secure mode choke. (lets call this file Wav1)
2. play the same audio CD (ofcourse same track) in your cd player, feed the spdif out into the soundcard's spdif in and record a wav file.(make this Wav2)
3. now compare Wav1 and Wav2. Consider Wav1 as the "reference" copy.
Differences would mean that the player is loosing traction somewhere.
Makes sense ?
2. play the same audio CD (ofcourse same track) in your cd player, feed the spdif out into the soundcard's spdif in and record a wav file.(make this Wav2)
3. now compare Wav1 and Wav2. Consider Wav1 as the "reference" copy.
Differences would mean that the player is loosing traction somewhere.
Makes sense ?
I am not an engineer ot tech-type, but I think that WAV1 will be digital and WAV2 analog recorded back to digital on the PC. The CD player to PC link is analog, unless you run an optical connection which you do not.
Can a tech-type verify this??
No, wav2 will not have gone through an D to A step. S/PDIF is a digital transmission from prior to the DAC. This is what it is all about.
In the circumstance of considering a CD player for purchase, making any such test might be difficult although some stores might cooperate if one brought along a notebook set up to make the test.
Extracting via EAC in secure mode is good, and very likely to return an exact copy of the file from the CD, but it is not guaranteed. If the same errors occur in multiple reads, EAC will have no external reference against which to declare them errors.
Starting with a file on hard drive, however you get it, and comparing the CD player's S/PDIF output with that file, will tell you how good the CD player's extraction is without necessarily saying anything about the file's original source or the method by which you obtained the file.
A CD with errors created by marking the surface might prove interesting for comparing different CD players, when read via the S/PDIF as suggested. Exactly what artificial errors might be most useful is another interesting question.
In the circumstance of considering a CD player for purchase, making any such test might be difficult although some stores might cooperate if one brought along a notebook set up to make the test.
Extracting via EAC in secure mode is good, and very likely to return an exact copy of the file from the CD, but it is not guaranteed. If the same errors occur in multiple reads, EAC will have no external reference against which to declare them errors.
Starting with a file on hard drive, however you get it, and comparing the CD player's S/PDIF output with that file, will tell you how good the CD player's extraction is without necessarily saying anything about the file's original source or the method by which you obtained the file.
A CD with errors created by marking the surface might prove interesting for comparing different CD players, when read via the S/PDIF as suggested. Exactly what artificial errors might be most useful is another interesting question.
QUOTE(goodsound @ Mar 29 2006, 03:02 PM)
feed the spdif out into the soundcard's spdif in
thats digital, not analog.
Professional playability tests for audio playback are usually done with ABEX discs
(TCD-721R, TCD-726, ...), Philips test disc (SBC444A, ...) and home made discs.
If you can get some of these discs with their clean counterpart you can compare
extracted files, otherwise just use your ears.
(TCD-721R, TCD-726, ...), Philips test disc (SBC444A, ...) and home made discs.
If you can get some of these discs with their clean counterpart you can compare
extracted files, otherwise just use your ears.
The digital output, via S/PDIF, of any CD can be compared with what's on hard disk via software. Extraction from a good CD-RW drive can be shown to be bit perfect this way (not necessairly every time of course). If you use a CD-R of files you've doctored for easy manipulation, you make the task a little simpler but any music CD can be used.
bringing up this old thread as I just happened to get this CD and run it in every transport in the house - from the discman to the clock radio to the dvd player to the cd-drives in the pc/laptop. And I got results all over the place. Some barely made it to Track 2. The Pioneer DV-563 player and the ltr-48246 were best - made it to track 4 easily, with a little ticking on track 5.
so what I'd like to know is - what makes a cd transport good or bad at error correction ? Is it the physical/mechanical construction or the intelligence (software/firmware) of the player ? I am seeking to find specific information as to what contributes ?
so what I'd like to know is - what makes a cd transport good or bad at error correction ? Is it the physical/mechanical construction or the intelligence (software/firmware) of the player ? I am seeking to find specific information as to what contributes ?
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