User Manual

EQ AND FILTER SHAPES
Bell Shapes
Q Definitions:
P – 3dB Classical definition that means Q is measured 3dB below peak for boost or 3dB above peak for cut.
0
– 3dB Definition used for bells in some US products, the bandwidth for Q calculation is measured 3dB below 0dB
l
ine for cut or 3dB above for boost. Q in both definitions correct only for +6dB boost/cut.
P/2 New ‘musical’ definition based on the bandwidth measurement in the middle of a bell filter, between peak
and 0dB line.
Normalisation 12 equalisers are normalised to have exactly the same bell shape for +6dB boost.
Classic Symmetrical (Classic Sym)
The most popular parametric EQ shape used in various mixing consoles and
outboard gear. Almost constant Q characteristic.
P – 3dB
Classic Asymmetrical (Classic Asym)
Often features in older equalisers. Boost as above but much narrower cut
characteristic.
P – 3dB boost
0 – 3dB (x2) cut
Proportional 1 (Prop 1)
Proportional equalisers are recognised as being more ‘musical’ than Constant
Q. The bells are wider below +6dB and narrower above +6dB (or –6dB for cut).
Proportional 2 (Prop 2)
Like Proportional 1 but with larger changes below and above +6dB peak
(or –6dB for cut).
P –3dB
Proportional 3 (Prop 3)
Like Proportional 1 but with extra widened bells between 0 and +3dB
(or –3dB for cut).
P – 3dB
Constant Q Asymmetrical (CQ Asym)
Used in some US products and mixers. The boost characteristics are defined
according to 0 – 3dB formula. Extra widened between –3dB and 0dB.
P – 3dB boost, 0 – 3dB cut
Duende Native User Guide Page 35