Legacy Products

HD-31 – High Definition EQ


The HD-31 (1/3 octave) is a high definition equalizer designed for use in sophisticated recording and sound reinforcement applications. Reliable and rugged units, the HD Series is the product of 10 years of research and development.

The HD Series offers the best in electronic components housed in an 18 gauge steel chassis for the ultimate in shielding and component protection. While exceptional design and automated assembly keep these equalizers competitively priced, A R T always offers the features one would expect in a professional unit. Faders are center-detented, sixty millimeter, high resolution type. All faders are equipped with large fader knobs. Signal Present/Clip, Power and Active/Bypass status LED’s are employed for user convenience.

The most innovative feature of the HD Series equalizers is perhaps the accuracy of the filter networks. Featuring constant Q active combining circuitry, there is virtually no center-point frequency drift regardless of the position of adjacent filter settings. The HD Series offers a new level of precision equalization and may be the most transparent and accurate equalizers available. From major rock & roll albums and tours to church installations, A R T HD Series equalizers have become the industry standard.