Getting rid of CDs, bit by bit

by zac

I am getting rid of all my music CDs, here’s why…

I went to a concert last night to hear Canadian Post-rock band Do, Make, Say, Think. Several of the band members were selling their side-project CDs and as an avid music collector my usual habit would be to purchase these discs at the show. Instead, I asked if the albums were available on the iTunes store… my transformation is complete.

There was a time when I wouldn’t even consider digital audio as an option. The combination of primitive MP3 encoders and people’s lack of understanding about low bit rates and their effect on sound quality flooded the online world with noisy, swirly-sounding MP3 files. For that reason, I was initially reluctant to start ripping my vast CD collection to MP3 format with an early version of iTunes back in 2004. Prior to that date, I had only used iTunes to RIP MP3 files to copy over to my 1st generation 10gb iPod. So what changed? Well, the world, really. Thanks to Apple, the download music model would become the standard, now outpacing sales of CDs and other physical media.

My migration to digital audio was triggered by a different incentive however. I had decided to reduce the physical clutter in my life and go digital in preparation for a move to China in 2005. The fear of living overseas without my music collection was enough to get the ball rolling and I started the arduous process of ripping 3,500 CDs to a hard disk with a bondi-blue Mac G3 Tower. Initially I used 160kbps MP3 as my standard bit rate, thinking it to be slightly better than the 128kbps that most people seemed to be using. Before I get too convoluted, a quick word about digital audio formats… (skip this if you already know about file formats)

Just like image formats, sound formats come in two flavours… compressed and uncompressed. Within compressed, there are two types of compression… lossy and lossless. I’ll spare you the details, but if you want them, look here (wikipedia) or here (Peachpit Press). So, skipping ahead – most people use lossy audio formats, just like they use lossy JPEG image formats… mainly because these are the default formats used by their software, computers or online sources. As the name implies, lossy audio file formats discard digital information to make the file smaller. And just like JPEG, higher compression means lower quality. Generally, a 64kbps MP3 sounds worse than a 128kbps MP3 and so on. Also, so you have an idea about file sizes, 1 minute of stereo audio in an uncompressed file format is just over 10mb, the same file compressed to 256kbps AAC is about 2.1mb – nearly 80% smaller. There are also lossless compressed audio file formats, but I’ll save those for another post.

By choosing the 160kbps bit rate for my MP3 conversion back in 2004, I had assumed that I was not only using a superior sample rate, but the most efficient compression method for a large collection. I was wrong.

The launch of the iTunes music store introduced AAC compression (advanced audio coding – a subset of MP4 audio), which Apple claimed would produce better sound than MP3 at the same bit rate (128kbps). About the same time, I started buying music from the iTunes music store, and therefore decided that I would encode all future CD rips in this new format, choosing AAC 160kbps as my standard sample rate. Then, Apple upped the ante by creating the iTunes Plus standard, allowing users to “upgrade” their previous iTunes purchases to DRM Free 256kbps VBR AAC files at about 30¢ per track. I initially thought this to be a money-grab on Apple’s part but the audiophile within me clamoured loudly for the higher bit rate.

By this time, my massive digital music library was awash with various formats and sample rates, ranging from AIFF and WAV to MP3 and AAC at an equally vast collection of bit rates. Could I hear the difference? Listening to different tracks, formats and sample rates didn’t work – I needed to compare apples to apples, so I prepared a test. I took a reference track that encompassed a wide spectrum of sound – detailed highs, complex midrange and layered bass sounds. Using the original CD as the control, I ripped the same track to MP3 320kbps, AAC 256kbps, AAC 128kbps and MP3 128kbps, then critically auditioned all the tracks on the same stereo setup.

I could go into great lengths about the subtle flaws and artifacts introduced to the music as the bit rate fell, but I won’t. Suffice it to say that I came to the conclusion that AAC 128kbps was pretty good for most styles of music, and I suspect many chronic iPod users wouldn’t benefit from significantly higher bit rates. However, discerning listeners wanting to listen to digital audio files on high end stereo systems really need to pay attention to bit rate. I found that anything less than AAC 256kbps or MP3 320kbps resulted in damage to the high end, muddying in the bass and an overall “flattening” of the sound. Interestingly, I couldn’t tell the difference between AAC 256 and MP3 320, reinforcing Apple’s introductory claim for AAC.

In any event, my migration to the digital audio world has been a one-way trip. I know this now, because I am finally getting rid of my 3,500 CDs after storing them for more than 6 years as a backup to my digital collection. But not before I re-rip every single one of them to AAC 256kbps… sigh!

Now I just have to deal with 14,276 vinyl records.

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