Much Ado About Everything

If you often have a need to extract audio from CDs and store it into a file on your computer, and you use Windows and know a thing or two about audio and computers, you’ve probably heard of Exact Audio Copy (EAC for short). If that’s the case, you are probably interested in which optical drive will provide you with best quality and highest extraction speed – whether you use EAC or not. I will mention my own experience here and while I used EAC, a lot of the information is not specific to that program.

Let’s be realistic – most people don’t care about audio extraction quality. That is not to say they won’t care about pops and glitches they might hear once they start using those files on their iPods – or wherever else they’re listening to them. However, if grossly audible artifacts are rare, people will tolerate them. And fortunately this is what happens most of the time – if you’re using clean, pressed CD as your source with any reasonable optical drive to do the extraction.

However, the life is often not that simple. I envy people who really can live like that. You know, people who find CD holders or furniture with built-in racks adequate for their purpose. People who can fit their DVD or VHS collection in the storage space under their TVs. People who can buy furniture and find that all the designed openings and holes fit their equipment nicely. People who have total of twenty or so clean trouble-free CDs that “just work” in their players. Who are these people??

If the above is not you – or if care about sound quality, getting their money’s worth or at least care about getting things done right, then read on. After all, if you paid good money to own a CD, why would you settle for error-ridden digital copy – whether audible or not? Or why not educate yourself a little and do the job the right way – as long as there isn’t much extra hassle? Or perhaps you don’t really care but you ended up with badly glitched files due to other circumstances – CD collection in non-pristine condition or bad quality drives – and are now looking for a solution?

If you’re an average user, you probably use something like iTunes to import your music from CDs into the library on your PC (or Mac). If you have more than handful of CDs, you probably noticed that if extraction conditions are less than ideal, you can end up with audible glitches in your files. Checking the “error correction” option in iTunes can help. But that isn’t the end of the story.

iTunes and many other programs (probably) use so-called “burst” mode to perform DAE (Digital Audio Extraction). On a modern DVD or CD drive (writable or not) this is a very fast process, often reaching 40 or even 48 times the speed of playback (so a 74 minute CD would end up being extracted in 74/40 – less than 2 minutes). If the CD is clean, this will be achieved and the result will be a clean file. However, even slightly dirty CDs may end up causing trouble at such high speeds. This is where the fun starts.

Every CD (or DVD) drive has the error correction mechanism (hardware + software) to deal with these errors. It is capable of fixing them on its own, before passing them to the operating system. But it’s also possible to have the drive flag the data instead and pass it as-is to the OS, leaving the interpretation (error detection and correction) to the user software. As far as I know, not a lot of software operates in this mode – probably for obvious reasons (extra development to do the same thing that the optical drive is already capable of doing). EAC calls this mode “secure”. As you may imagine, by not having the drive correct the data, you are faced with prospect of reading raw data at least twice and comparing it, and then reading even more times when a mismatch occurs in order to determine the real data by the majority rule.

Things aren’t so cut and dry, unfortunately. There are more variables here. First, the process of getting raw data is not equally reliable on all drives. Certain features such as audio caching can make it difficult for the reading software to know what is it that it’s getting. For example, if you ask to read the same section of the drive several times consecutively, the drive might just cache the results the first time and keep returning that same data over and over. Or, it could return data with different offset each time (because it’s designed to stream audio, not provide random access), making it difficult to know the exact position of the data you’re getting within the track. And then there’s error reporting.

Optical drives are capable of reporting errors they encounter during reading. Unfortunately, this isn’t simple either. There are various types of errors, for example C1 and C2 for CDs and PIO, POE for DVDs – and these themselves may be composite errors (i.e. a combination of several other types of lower-level errors such as E11). Then there’s the issue of what is drive actually doing – is it fixing the errors it finds and reports the errors, or only reports errors when it can’t fix them? How often a false alarm occurs, and how often a real error is missed? And what is the accuracy of its error reporting?

You can try to wrap your head around all this – and this is only the beginning. But if you do, you’ll find out that there are just no simple answers. For example, a drive might report 100% of errors it finds with 100% accuracy – but due to bad mechanical design (optics) it would be reporting far more errors than another drive. In other words, it will correctly report that it can’t read a position on the disc, but that same position would be read just fine on any other drive. Or a drive might have bad error reporting accuracy and not report many cases where it actually encounters an error (or report errors when there’s none) – but the errors themselves in the extracted data are actually much less frequent than in other drives. This makes it impossible to answer a seemingly simple question “what is the best drive?” or “what drive should I get?”. While in theory there might exist a perfect drive, in reality there is no drive that is perfect (or even) sufficiently good in all relevant categories.

So I believe the only way to get useful answers in this case is to change the question. The correct question is “what is it that you want to do?”

I will start from the end – the conclusion – because explaining in detail the whole investigation I went through would take too much time and wouldn’t be interesting to many.

In my case, I want to extract my CDs into audio files with NO errors whatsoever. Provided my discs are in reasonably good condition, I feel this is a reasonable request. I would also expect very good ripping speeds on such discs. Even if discs are damaged , I expect them to be extracted perfectly – within reasonable limits of course. I am also willing to pay the penalty – speed penalty and convenience penalty – to get bad discs extracted well. I am however only willing to pay minimum convenience and speed penalty to extract good CDs – which are vast majority of my collection. Given the number of CDs I own and their condition, it would be a colossal waste of my time to take half an hour ripping just one out of hundreds of CDs, almost all of which are clean and unscratched.

This request can be rephrased: what do I use to (and how do I) rip CDs fast and with minimum amount of errors, but be reliably informed if the errors do occur? And the subsequent question is “what do I do when I do get informed about errors?”

The part “rip fast with minimum errors” depends on the quality of optical drive – it’s combination of its mechanism, optics and firmware. I first tried to determined this by making a custom test CD according EAC DAE Quality web page. It’s a cheap way to do one of those fancy CD read quality tests that big review sites put up. The results are presented below. On the horizontal axis you have time in minutes (total of 74 minutes) and on the vertical axis you have error loudness in dB with 5dB granularity; black line on top is 0dB, and so if red line is a flatline on the bottom, that means that there were no errors.

Benq 1655 (score 81.8 out of 100)

LG 4163B (score 76.9 out of 100)

Lite-On LH-20A1S (score 87.8 out of 100)

Plextor UltraPlex 40X SCSI CDROM (score 52 out of 100)

Pioneer 111D (score 82.6 out of 100)

Lite-On LTN-57s CDROM (score 61.3 out of 100)

As you can see, the best performance seems to come from the latest drive I got only a few days ago – Liteon LH-20A1S. Benq 1655 and Pioneer 111D are close behind. However, if I run the second test to get the C2 error reporting accuracy, I get pretty low 73.5% result on Liteon. Two other good drives are not able to report C2 in the way that the test software expects so I don’t know what their accuracy is.However, how useful is this test really? We can find it on a real example, a pressed audio CD that has errors. While this CD looks really clean, I found out by chance that some of its tracks don’t seem to extract well. Problematic tracks were 2, 3 and 10. I decided to use 10 as the reference and read it in all drives I have, and then attempt to clean the disc and get the hopefully reference (clean) data and compare with what each drive returned.

The results were surprising. Out of all drives, not a single one was able to extract track 10 without errors when in burst mode, even if the read speed was lowered (I haven’t tried very low speeds though). While that wasn’t too unexpected, I didn’t expect to get a lot of audible errors on certain drives seeing how they managed to keep the glitches pretty low during tests with the artificial test CD. And errors were very audible and quite frequent, though not in the same part of the file for all drives. Ignoring (or not) the C2 error reporting made a difference, but not necessarily in the right direction. Also, while EAC did report suspicious positions, often there were no audible errors there – and there were audible errors in the parts that were not flagged. Of course, in a number of cases it correctly flagged a problematic region. On the plus side, the extraction was pretty fast even though all drives slowed down as they started hitting errors.

When the test was run in secure mode, only Benq 1655 and Liteon LH-20A1S have read track 10 without errors. By that I mean that the binary comparison of the extracted file revealed no differences whatsoever when compared to reference file. That’s the good news. The bad news is that secure mode extraction is extremely slow, rarely faster than 8X – while there are no errors – and as slow as 1.6X overall, given that there were errors.

Additional tests showed that while Benq and Liteon were also able to read track 3 correctly in secure mode, only Benq was able to also read track 2 without errors; Liteon did have an error on track 2 even in secure mode.

So my conclusion was that out of all drives I own, only Benq 1655 was able to reliably read the (invisibly?) damaged CD. Liteon LH-20A1S was almost as good, and Pioneer 111D was acceptable (the errors weren’t frequent, and they weren’t audible). All other drives were quite simply bad – and yes that includes legendary Plextor Ultraplex 40X. Sure, many of these drives were old but so what – they are simply not capable of doing a good job today and that’s all that matters.

Unfortunately, results of this test didn’t help me much at all. In secure mode, all three “acceptable” drives were very slow, with extraction speed in single digits and sometimes barely better than real time. This is not a solution for extracting a big library of CDs which don’t have errors; it’s simply too slow. To make matters worse, the only error-free drive is not in production any longer; in fact its manufacturer was bought out last year and is now defunct. At the sample I have pretty much sucks for anything other than – apparently – ripping CDs.

In the end, I stumbled upon a solution to my problem. EAC has a copy & test feature; this will rip audio, then rip it again and compare CRC (checksum) to find out if extractions are identical. If I now extract a CD in burst mode, by taking a quick look at two columns on EAC screen (or the extraction log presented after each extraction) I will be able to find out whether there were errors during extraction. I can then put those CDs aside and afterwards extract them slowly in secure mode.

And what optical drive to use then? I cannot in good conscience recommend Benq 1655; while it seems to do a great job as CD reader, it is the worst DVD writer I’ve ever owned. This is in stark contrast with community opinion, which claims that Benq 1655 is one of the best DVD writers ever. The only way that could happen is if my unit is defective. Regardless, that points to quality control issues. But that in itself is irrelevant because Benq division that was making optical drives doesn’t exist any longer. With that in mind, I’d have to say to get either Liteon LH-20A1S or Pioneer 111 (or perhaps 112, the newest iteration which should be fairly similar). Both of them have some advantages, but I believe Pioneer is generally considered one of the best writers on market right now.