Tapco T-231 Introduction, About Graphic Equalizers, Constant Q Design, Whazzit Used For?

Introduction

Thank you for choosing a TAPCO® Tweeq™ 31-band graphic equalizer by Mackie®. The TAPCO product line hails back to the days of TAPCO Corporation, Greg Mackie’s first company. TAPCO revolutionized the audio industry back in 1969 with the very first 6- channel mixer specifically designed for keyboards and rock ‘N’ roll PA.

In essence, TAPCO redefined the price performance ratio and made high-quality professional audio mixers accessible to virtually anyone. Today, TAPCO is reborn with the same ideals and is backed by the world-class engineering and manufacturing horsepower of

Mackie. The TAPCO T•231 is the first graphic equalizer in the TAPCO by TAPCO version of Greg Mackie® family.

About Graphic Equalizers

The tone controls on your home stereo system typically have a bass and treble control, and sometimes a midrange control, that you use to boost or cut a broad band of frequencies. When you leave the controls in the center position, they do nothing.

A graphic equalizer works in much the same way, except that it has many more controls that operate over much narrower frequency bands. The T•231 has 31 controls that boost or cut different frequencies, each centered on ISO standard frequencies ranging from 20 Hz to 20 kHz and affecting 1/3 of an octave.

Constant Q Design

The T•231 is designed with constant Q filters. The Q of a filter refers to its quality. A filter with a low Q affects a broader band of frequencies than a filter with a high Q (Q=fc/BW, for you technoids!). Constant Q means that, as a slider is boosted or cut, the bandwidth of the filter (the “skirt” of the affected frequencies) remains the same. Lower quality proportional Q filters have a broader bandwidth as the filter is boosted or cut, which can extend out to an octave or more.

Whazzit Used For?

There are a number of uses for graphic equalizers in a sound system. They can be used to correct the frequency response of a loudspeaker, or to adjust for resonant peaks and dips in a room. Sometimes they are used to simply bring out the characteristics of a voice or instrument to improve the intelligibility and articulation of the sound.

In any case, please remember that a graphic equalizer is a tool that can be used to improve the overall sound, but it cannot make up for frequency response deficiencies caused by poor system design or poor acoustics. Try and get the best possible sound from the system before attempting to use equalization by paying attention to proper gain structure and loudspeaker placement. Often times just moving a loudspeaker to a different position can have a dramatic effect on the overall sound in the room.

Probably the most common use of a graphic equalizer is placing it in-line between the mixing board’s main outputs and the power amplifier inputs (see hookup diagram on page 8). When used with a real-time analyzer and pink noise generator, it can be used to fine tune the acoustic frequency response and get it as flat as possible in a room.

TAPCO van (a.k.a. micro bus)

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