Computer Music 5: choosing the right format

Two orders of business to attend to before we get started. First, happy thanksgiving! Second, I messed up the link in this month's newsletter to John Darko's article entitled 12 reasons why high res audio will never go mainstream. Click here to read the actual article. Sorry about that. We left yesterday's discussion with the knowledge that what's recorded onto a CD must be placed into a container before a computer will recognize it. And there's a lot of confusion as to which container and format is best. Understanding the good and the bad of the formats is essential in the early part of your computer audio journey. This is the time when you want to make sure you get the data in the right form. So it's worth taking some time to understand what's going on. First, a little primer. What's on a Red Book CD is a continuous stream of data. Music spools off the CD and is sent from the player/transport to a DAC, through a cable, and you hear music. But computers aren't transports. Computers are fussy things that don't know what to do with a continuous stream of bits. Instead, they like their data broken up into chunks–like a child who needs a parent to first cut up their meal. Each of these chunks needs to be placed in a container, and the container needs a label that tells the computer what it is–like buying packaged food at the market. The computer doesn't look at the bits inside the container (the bits contain the actual music). Instead, computers read only the label attached to the chunk of bits and then route the entire chunk where it needs to go: stored on a hard drive, sent out the USB port. When you put a CD into the computer's disc reader–the tongue that extends out of your computer–what's the first thing that happens? It reads what's on the disc and makes a guess as to what you want to do with it. If you have installed iTunes, and the disc is a CD, it will guess you want to add what's on the CD to your computer. If that is, in fact, what you want to do, the process is rather simple, it just does it. But how does it just do it? iTunes assumes you don't know what you're doing and just does it for you. iTunes assumes you're not an Audiophile. iTunes assumes you're only interested in storing music on your computer for casual listening, or perhaps transferring to your iPod or phone. iTunes never assumes you want high quality lossless music. And so we must tell it otherwise; bring it up to speed with who we are! But, before we do that, we need to know what we want and why. Can we agree up front none of you reading this blog want to lose quality from what's on your disc in the first place? There are two choices we have to make right away: lose musical quality or keep quality. I am assuming you want to keep it. What iTunes is going to recommend is the opposite–they think you're ok with lower quality than you started with–called lossy–instead of preserving what's on the disc–called lossless. Containers that lose data have names that may be familiar to you: AAC, MP3, Opus, Vorbis, WMA lossy. Stay away from these. They are bad for your musical soul. The formats we're interested in do not lose quality, though there are other considerations which we will get into. Those formats are divided into two groups: uncompressed and compressed. Both retain all the information present. The most popular uncompressed formats are WAV and AIFF. The most popular compressed formats are FLAC and ALAC. Today's takeaway: Do not assume iTunes is your friend. iTunes must be setup properly before copying music to it.