The Power of Analog Signals

I’ve recently upgraded my speakers and things are sounding fantastic around here at the moment. (Although I am a bit disappointed to discover that I was sold “last year’s model” that in truth was discontinued in 1999, gonna talk to them about that.)

Yesterday my friend Bob came over with a stack of his CDs to check them out for himself. It’s likely to have been an expensive visit for him because he agreed with me about how enjoyable the speakers are.

We listened to probably 30 discs, with a wide range of production values. A handful of those discs were obviously poorly produced and their flaws were laid bare. What was interesting was that those crummy discs were pretty evenly distributed across the time period we listened to… from the old days to today.

Anyway, bad CDs isn’t the point of this blog entry. The point of this blog entry is to discuss the obsession that people seem to have with digital things. My new speakers, for example, have the words digital monitor on the box. These are speakers, folks, they accept an analog signal and produce analog soundwaves. What’s digital about them? Nothing. Why do they say digital on the box? Marketers have decided that its a desirable term.

Anyone who thinks that CD audio is equivalent to an analog recording has never listened to a variety of CD players side-by-side on the same equipment. CD players are an instrument (in the musical sense), and vary in their ability to perform (in the musical sense) the string of numbers on the disc. CDs have many advantages over traditional analog recordings in terms of longevity, and it is true that digital signals are largely due immune to noise (although this is not true in digital devices with poor power supplies, which is most of them). I am not a vinyl purist, I think the tradeoffs made by CDs are good. But I am not onboard with the digitization of broadcasting (e.g. digital radio) which requires ridiculous destruction (compression) of the audio data.

Today I’m listening to CKCU and the audio sounds just as good as if I were listening to those CDs right here in the house or in the studio. Yet, CKCU is broadcasting that signal over the air from 20 km away, and it can easily be received by everyone in a 100 km radius.

Radio signals broadcast in FM are analog signals, and can (in theory) reproduce signals exactly at huge distances. All the subtleties of the buzzing of the pipes, the breath sounds of the singer, the fret noises of the guitar are coming through in fantastic detail. Once decoded into analog by the CD player at the station, this 50 year old technology is beaming a perfect copy of that signal into my house and onto my speakers.

Many people these days are easily satisfied. They purchase 128 kilobit/s recordings from online stores and listen to crummy feeds from around the world. These feeds surely offer an inexpensive and plentiful source of music. From a cultural point of view they are great. But they don’t stand up to good old FM radio for reaching power and good listening.

return to cmh blog

› technology     2006-01-29 14:05   ...0