Meeting Topic: Lies, Damned Lies & Specifications
Moderator Name: David Bowles
Speaker Name: Jonathan Novick (Audio Precision)
Meeting Location: Cogswell College, Sunnyvale, CA
When presented with a list of specifications, one needs to know how to read them, and in particular, to realize when reference information is missing or misleading. For instance, one advertisement was displayed violated Ohm's Law! Other instances were shown where THD - a non-standardized specification - appeared nonexistent. While this might sell more power amplifiers and loudspeakers it leaves to much to the imagination.
Throughout the presentation an audio analyser was used, one of several on the market. The sound samples ranged from sine waves and pink noise through several different well-known pop recordings.
On several occasions, our ears and levels of perception were tested by the selective addition of several types of distortion. Some of these types of distortion showed up using one method of measurement, and didn't show up using another method! This illustrated the "Lies" of Jonathan's title; Mark Twain would have approved of the borrowing of his phrase.
Written By: David Bowles