Equalisers

The ITI MEP-230 is one of the earliest production parametric equalisers, likely emerging around 1971, and represents a refined implementation of Massenburg and Macneal’s early parametric EQ concepts. Its scarcity and evolving internal histories complicate exact documentation, but its role in the lineage of mastering EQ is clear and influential.

Klein & Hummel’s UE 1000 is a discrete, programme equaliser from the 1970s aimed at mastering and programme work, valued for its musical networked filters and solid professional construction.

The ITI MES-430 was the first commercially available parametric equaliser, a design once thought impossible to achieve, created by the brilliant George Massenburg.

Introduced in 1976, the Crown EQ 2 Graphic Equaliser combined two channels of eleven-band equalisation with independently adjustable bass and treble shelving controls. Each equaliser band offered stepped boost and cut together with a variable centre frequency, allowing adjustments between the nominal octave centres. Its combination of broad tonal adjustment and more selective frequency correction formed Crown’s synergistic equalisation system, intended to compensate for response irregularities in audio equipment, room acoustics and recorded material.

The MXR Thirty-One Band EQ is a professional-grade graphic EQ introduced in the late 1970s, offering precise tonal control for studio, live sound, and broadcast applications. With 31 frequency bands spaced one-third of an octave apart and a ±12 dB adjustment range, it allows for detailed sound shaping, feedback reduction, and room correction. Its rugged 19-inch rackmount design, high-quality faders, and connectivity options – including 6.35 mm jacks and XLRs – ensure durability and compatibility.

The MXR Dual Fifteen Band EQ offered precise two-channel frequency control with bands set two-thirds of an octave apart for greater accuracy, particularly in the midrange. Each channel had its own level control, with a ±12dB range per band, housed in a rugged 19-inch rackmount design with quarter-inch connections.

The UREI 545 Parametric Equaliser is a four band true parametric equaliser with continuously variable frequency, bandwidth, and gain, offering precise and flexible control for professional audio applications.

The Orban 622 Parametric Equalizer was a true constant-Q professional parametric equaliser with four independent sections per channel, wide tuning ranges, deep notch capability, low noise and low distortion. Available as the single-channel Orban 622A and dual-channel Orban 622B, it was built for studio, broadcast, live sound, theatre and motion picture applications.

The 360 Systems Model 2800 Programmable Equaliser was a fairly unique product at the time of its release in 1980, with its tactile controls and programmability. Using a Z-80 microprocessor and CMOS memory storage, the 360 Systems Model 2800 Programmable Equaliser was able to store up to 28 user created EQ curves.

The Ibanez MSP1000 is a versatile processor with a compressor/limiter, graphic EQ, and notch filter. It offers precise control, eliminating feedback and shaping sound without affecting quality.

The Boss RGE-10 Graphic Equaliser from 1985 provides fine tonal compensation with 10-Band Graphic Equaliser.

The Boss RPQ-10 Preamp Parametric EQ released in 1986, is A 2-band Parametric Equaliser that’s a key performer when creating sounds.