Saturday, March 19, 2011

Digital Dilemmas, Part I: Ripping

It has been a while since I have mused about stereo equipment. That's because what I have (mostly) works. The law of diminishing returns definitely applies to audio equipment: things get very expensive very quickly, often with marginal audible returns.

The way we listen to music has been transformed drastically over the last decade, or so. This originally started with the MP3 player, which was never intended as a high fidelity medium, but exploded with the iPod. This technological leap may have improved ease of access to music, but it has often done so at the price of sound quality. (Also at the cost of hearing, as the ubiquitous ear buds can channel a lot of volume directly down the ear canal.)

I switched to digitally encoded and stored music several years ago when several of my friends raved about "squeezeboxes," which allowed you to store your collection on a computer and stream it out to a remote playback device – the squeezebox. My entire collection has since been transferred to a computer disk. This involves "ripping," which seems like it should be fairly straightforward: simply copy the bits on the audio CD to bits on the disk. How hard could that be?

Most of the time it is pretty simple: iTunes simply reads the CD and stores the bits correctly. I always do this using a "lossless" format, which takes up a lot more disk space, but which preserves all of the detail of the original. Part of the dilemma is that I noticed very occasionally there were defects in a track, sometimes sounding very much like a skipping record, sometimes resulting in pops that sounded rather like old record scratches.

It turns out that it is not as simple as "bits-to-bits." I'm going to over-simplify the situation a bit: audio CDs don't store bits the same way as computer data files, so that capturing those bits in proper sequence, especially given underlying inaccuracies in CD drives, can be a problem. Most of the time, it is not a problem; out of my over 1,000 CDs, which is just under 20,000 tracks, I think I have noticed problems on perhaps 20 tracks. That is approximately a 0.1% error rate; if you have 100 CDs, you might have one track with a problem, so you may never notice it. In fact, my older CDs seem more prone to problems, so it is possible you will never run into this.

There are specialty programs (generally freely available) that do a much, much more careful job of ripping, finding and correcting most problems. All it takes is a lot more time. I have been busy re-ripping my problem albums using a program called "XLD" and my problems seem to be going away. Having ripped so many CDs, I'm not about to go back and re-do everything. However, I will be using it for new CDs.

There are many advantages of these digital libraries. It is much easier to find a recording. It is easy to transfer it to a portable device, like an iPod. Perhaps what gives me the most comfort is that I have a backup of these many precious recordings, many of which can no longer be obtained. In fact, I periodically backup that backup! If another wildfire threatens our home again, you can be sure I'll grab my computer disk first.