alan little’s weblog

steve on compression

30th September 2005 permanent link

Steve Crandall, who knows a great deal more about these things than I do, has some interesting thoughts on acceptable bitrates for digital music:

If you have space lossless is good, but not always detectable. Some very serious double blind tests suggest 128kbps AAC is probably good enough for any ears over 40 years old and many younger ears. 160kbps AAC fools serious ears very well.

Being of a nervous disposition, I back my CDs up using Apple Lossless. But the 250 GB hard disk I put them on is rapidly filling up, and maintaining two copies of things – a slightly compressed archive copy, and a much smaller copy to go on my iPod – is a pain in the ass.

It is a different matter if you are using something recorded at better than CD rate. We did some work with AAC compression on very high bit rate input audio and had much better than CD sound with files much smaller than CD files. A problem is very little is prepared for sale at high quality. A larger problem is most people just don't care. Regular mp3s seem good enough for most people and few people have the $300 headphones or $3000 speakers you really need if you want to focus on the differences.

It’s laughable that people sill regard the quarter of a century old CD standard, or compressed formats that are indistinguishable from it, as some kind of benchmark of sonic excellence. But it’s Good Enough for most people for most purposes, and for the foreseeable future anything better is likely to be so heavily DRM’d it will be useless.

I have a pair of $200 headphones. I bought them used on ebay for nowhere near $200.

(I'd rather put that sort of money into live music...)

Of course Steve’s right in principle. But I have a small child and don’t get out much, and in the evening after I’ve put my small child to bed I like to sit down in the living room and listen to some recorded music (on my $200 headphones). There’s also the They Don’t Make Musicians Like That Any More problem: if giants like the Smetana Quartet still walk the earth, I don’t know who or where they are.

related entries: Music

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