Recording Classical Music

CHAPTER 7 EQ

Digital Filters

In the early days of telephonic communication, long cable runs caused such a loss of high-frequency content that the quality of a signal’s output was markedly inferior to the input. Electronics engineers compensated for this deficiency by employing a circuit to boost high frequencies. This circuit, called an equalizer, allowed the output to become roughly “equal” to the input.

Today, audio editors use equalization (EQ) to modify the frequency content of signals to enhance the aesthetic appeal of individual or combined tracks. Recordists often achieve these alterations through digital filters, devices normally classified according to type: pass, shelf, parametric, and graphic (I define the term “filter” as any device ...