PS AUDIO: Pondering

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Paul McGowan: Yesterday I proposed a thought problem once again.  This time we compared the direct output of a stereo microphone vs. the recorded output of that same microphone while a group of acoustic musicians played in a room separate from us – and we could hear a difference between the recorded version and the direct live feed.

A few days earlier we did the same experiment with an electric guitar feeding an amp/speaker combo while in the same room and we couldn’t hear the difference. Many of you speculated the greater resolving power of the microphone vs. the magnetic guitar pickup was the difference.  I disagree.  I think the difference is two fold: stereo and familiarity.  Let’s start with familiarity first.

If you look closely at two identical photographs of a piece of modern art you’re not familiar with – and one photograph is a slightly lower resolution than the other – chances are good you’ll not be able to tell the difference between the two photographs.  But take that same experiment and replace the subject matter with a closeup of a human face and you’ll have a much different experience.

This is because we humans are exceptional at pattern recognition.  Once we have lived with a certain pattern for a long time we can almost always pickup on subtle differences between those patterns – even very complex patterns – almost instantly.

In the guitar example most of us don’t know what this guitar setup should sound like and therefore the subtle differences between the recorded vs. live go undetected.  The same cannot be true for a small group playing live music or the sound of a human voice – something we are all much more familiar with.

When you hear the sound of a reproduced instrument you are intimately familiar with – even the subtlest of changes are easily detected in this complex pattern.  That’s one major reason we can hear one and not the other.

Tomorrow we tackle the bigger issue.