Using The Hf Curveshaper™ Eq - AEA RPQ2 Owner's Manual

Using the HF CurveShaper™ EQ
The RPQ2 features a unique CurveShaper™ circuit that enables you to
add a little extra "presence" or "air" to compensate for high-frequency
losses that are inherent to most ribbon microphones, the result of
distant mic placement, or to restore presence in a "dry" acoustical
environment.
The circuit functions similarly to a conventional parametric shelving
boost but with a significant difference: the slope and bandwidth varies
as both the Curve Frequency and Curve Gain controls are adjusted.
From a technical standpoint, it is evident the EQ shape of the
CurveShaper™ is a bell. At its lowest setting, the peak frequency of the
CurveShaper™ is 30k while at its highest setting, the peak frequency is
120k. In many instances, a bell with a peak at 120k is not very practical
since it is above the human frequency threshold of hearing. But the
CurveShaper™ has a very wide bandwidth that allows the left side of the
bell to essentially act as a high-frequency shelf.
The Curve Frequency knob, at its lowest setting, will yield a gentler
slope and wider bandwidth. As the frequency is raised, the slope
becomes steeper while the bandwidth narrows.
To activate the CurveShaper™ EQ section, depress the High Frequency
switch (ref. #3). Start by adjusting the continuously variable Curve
Frequency control (ref. #4). The frequency markings on the Curve
Frequency dial indicate the +3dB break-frequency when the Curve
Gain is at max. Select the desired frequency with the Curve Frequency
knob, and then dial-in the amount of boost you desire with the Curve
Gain control (ref. #2). The two controls are interactive. Use your ears to
determine what frequency and gain setting sounds best.
In Line Input Mode, the CurveShaper™ becomes a versatile EQ to add
presence or air to any line level signal on a mix or even in mastering.
Be careful when you add Curve Gain because this also affects the
overall gain structure of the preamp and could introduce overload
distortion. After you make this adjustment, you may need to reduce the
Output Level control (ref. #5) to compensate for the CurveShaper's™
signal boost
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