PRESONUS STUDIOLIVE 16.4.2 - V1.12 User Manual page 61

2 Controls & Connections
2.10 Digital Effects | Master Control
The System Menu
2. 1 0.4
In an analog EQ, this is achieved by carefully choosing the bandwidth of the filter and deciding how or if it
varies with the gain and how the filters are summed or cascaded. In general, narrower bandwidth signifies a
higher quality EQ. But in traditional graphic EQ designs, the center frequency of each band is fixed.
PreSonus took a different approach with the StudioLive. The StudioLive Graphic EQ is a pool of shelving
filters from which coefficients like cutoff frequency, bandwidth, and gain are extracted through a process of
curve fitting. The curve entered by the user is first oversampled. The system then works with an internal
curve made up of 128 bands to find coefficients for the first shelving filter that, when subtracted from the
user's curve, will produce the flattest possible response: 0 dB. The resulting response is then used to
find coefficients for the second shelving filter through the same optimization process. Coefficients for all
available shelving filters are found through a recursive process.
Unlike conventional designs, the frequency and bandwidth of the "bands" depends on the curve entered
by the user. This allows for much tighter matching of that curve. Because of this innovative design, the
accuracy of the StudioLive EQ might feel "wrong" at first. The curve fitting process is capable of very steep
transitions and, unlike conventional analog graphic EQs, what you see is what you get. With a carefully
drawn, smooth curve the StudioLive EQ will have almost no frequency ripple. The StudioLive EQ is also
capable of very sharp notches. To widen a notch or a bump on a particular band, just bring the adjacent
bands closer to that band's gain and the bandwidth will change accordingly.
Press the Page Down button to view the firmware version
currently loaded on your StudioLive. You normally will
only view this screen when performing a system update,
in order to confirm that the new firmware was successfully
loaded.
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