Fun With Audio Codecs
There is more to life than MP3.
I've experimented with many different audio codecs over the years. For those who don't know, an audio codec is a way of recording audio to a file. These files can then be played back from various devices. These days, that device is usually an iPod. Music players like the iPod are often incorrectly referred to as 'MP3 players'. People call them this because MP3 is the de-facto standard for audio files. Pretty much every music player in existence will play MP3 files. Most people hear the term MP3 and they automatically understand what it means. But just because MP3 will work everywhere, doesn't mean it's the one you should use. Lately I've been coming to the conclusion that MP3 is one of the worst formats you can use to record audio.
Why do I think MP3 is so bad? Because it is one of a class of what are called 'lossy' codecs. This means that when you encode something in MP3, there is a loss of some of the quality of the music. Essentially, some of the music is lost in the process of encoding it. This means that what you hear on the MP3 file will never sound as good as the CD it was ripped from. This lossy nature of the codec is done for a very good reason - file size. In order to shrink the file size down to a reasonable size you need to discard some information. The trick is to find a balance between file size and audio quality. An MP3 file on average runs about 1MB per 1 minute of audio. If you were to store that same audio in a lossless format, it would run about 10MB per 1 minute of audio. This means that by using MP3 you can essentially fit 10 times the amount of music in the same amount of space. This is one reason MP3 is so popular. Even with a small 1GB flash based music player, you can fit up to 1000 minutes of music on it! That works out to over 300 or so songs. That's more then enough for even the longest workout! Now expand that to a 60GB iPod and that means you can essentially store 60,000 minutes of music on an iPod. That's 20,000 songs! (assuming 3 minutes per song).
If you have an iPod, or for that matter, any other music player, don't be so focused on only using MP3 files. There are other, better formats that, based on my observations, do a much better job of balancing the quality/size issue. I'm going to discuss a few other audio codecs that I've played with and my impressions on how they match up to MP3.
Apple Lossless
This format only works on the various Apple iPods (and the AppleTV). It is the 'gold standard' in audio codecs. Why? Because it is a lossless codec. This means that literally what you hear is what was on the CD you encoded it from. The sound quality from this format is fantastic. If you are an audio purist, this is the format you use. The problem is that, since it is lossless, it generates big files. These files can run on average 10MB per 1 minute of audio. That's about 10 times the size of an MP3 file. Of course if you have the space, this is the way to go. At one point, I had my entire CD collection of over 100 CDs ripped to Apple Lossless. I had loaded this music onto my iPod and it sounded fantastic. While I enjoyed that the music sounded fantastic, I didn't like that I couldn't fit much on my iPod. My large CD collection ripped as Apple Lossless was well over 80GB. This was more than twice the size of the iPod I had at the time (a 40GB iPod), so that meant that at best I could only keep half of my collection on the iPod at any given time. Granted, I don't actually listen to my entire collection, but I wanted to have it all there if I wanted to listen to it. I also didn't like the idea of filling up the iPod completely. I always like to leave some free space on the iPod. After a few months of this, I decided that I couldn't deal with it, so I wiped the iPod and went back to the old standard - MP3. I had my entire collection on the iPod with space to spare, but the sound quality wasn't all that great. I'm no expert on audio quality, but after listening to Apple Lossless, I could definitely tell that MP3 wasn't there for me.
AAC at 256kb/sec
This is, not so coincidentally, the audio format used by the new iTunes Plus that Apple just released a couple days ago on the iTunes store. Back in April, when Apple and EMI first announced the DRM-free iTunes Plus deal, I knew little about AAC. I had always thought that AAC stood for 'Apple Audio Codec'. Being the stickler for standards that I am, I never bothered to look into this format. "It's an Apple only format! I don't want it!". They announced that the iTunes Plus songs would be encoded in AAC at 256Kb/sec. They said this was 'near CD quality.' This piqued my interest. Yeah, it could all be just a bunch of 'marketing speak' to attract interest in this new service, but I decided to test this proclamation myself. I decided to see if AAC was as good as they said it was. The next day I started re-encoding my entire CD collection again at AAC 256Kb. It took about a week of feeding CDs to the computer to do it, but I finally got it all converted. I loaded it all up on the iPod and started listening. I have to say that I am impressed! I am starting to hear subtle little things in the songs that I never heard in the same song encoded in MP3. This format seems to be almost as good as Apple Lossless at considerably less space. AAC files seem to run about 2MB per 1 minute of music - twice the size of an MP3, but well worth the extra space. This is a bit of a concession to sound quality, but considering how much better they sound, I don't mind. Also, I discovered that AAC doesn't stand for 'Apple Audio Codec', it stands for 'Advanced Audio Codec' and it is an industry standard. It's used on the Playstation 3! That's definitely not an Apple product! I have been trying to get through on iTunes Plus to purchase a couple of their songs which are also in this format, but I haven't had any luck at this. The iTunes store has been acting very flakey for the last few days. No doubt they are getting swamped with people trying out iTunes Plus. I'm going to keep trying until I can get in and buy a few. This sound quality is just too good, and it is worlds better than their old DRM format's quality. I never much cared for the sound quality of those recordings.
I have to admit that I have a few 'less than legal' MP3s. Despite the 'free' nature of these MP3 files, I'm rapidly reaching the conclusion that they are useless. The sound quality is absolutely horrible and they aren't worth listening to. Yes, you have to pay for iTunes Plus or for the CD that you rip to AAC, but the more I think about it, the more I think that you get what you pay for. The great improvement in sound quality from high quality AAC recordings over low quality MP3s make them very much worth the money you pay for them. While I still prefer to buy a CD and rip it to AAC myself, at least now the iTunes store has sound files of good enough quality that I can see myself buying them.
Be adventurous. Try AAC. You'll like it much better than MP3. Now I understand why iTunes defaults to ripping to AAC. It's BETTER!