4 Common Type of EQs

Filters

• Were the First Equalizers in Broadcast

Low Cut / High Cut

• Cut Frequencies from a Selected Point

Low Shelf / High Shelf

• Boost Frequencies from a Selected Point

Graphic Equalizer

• Came After Filters

• Fixed Selected Frequency Points which you can Boost or Cut

• API 560 EQ

• Frequency Points are Close to Octaves

Parametric Equalizer

• Came After Graphic Equalizers, Invented by George Massenburg

• Added the Q Factor to Go from Narrow to Broad and Reach Out for More Frequencies than the Graphic Equalizer was Able to

• e.g. a High Q of 1 Could Affect 900Hz to 1kHz while Low Q can Reach 750Hz to 1.2kHz

• Semi Parametric has Gain, Either Selecteable Frequency with No Q or Only Selecteable Q on a Couple of Bands (but Not Both)

• Fully Parametric has Gain, Selecteable Frequency and Selecteable Q

Linear Equalizer

• All Analog EQs are Minimum Phase, so Linear is a Digital Option Only

• Linear Equalizer Goal is to Avoid Phase Issues