API Select SR24 Dual-Channel Parametric Equalizer Dual-Channel 4-Band Parametric EQ With Continuosly Variable Frequency And Boost/Cut Controls

API 550B 500 Series 4-Band Equalizer Processor Modular 4-Band Equalizer, 500 Series, With 7 API-Selected Frequency Centers, 12Db Of Boost/Cut Per

API 560 500 Series Graphic Equalizer Processor Modular 10-Band Graphic Equalizer, 500 Series Classic Reissue, With 12Db Of Boost/Cut Per Band,

API 550A 500 Series 3-Band Equalizer Processor Modular 3-Band Equalizer, 500 Series, With 5 API-Selected Frequency Centers, 12Db Of Boost/Cut Per