Software Instruction Manual

IQ–MSD Turbo 1.4 Advanced IQ System Software
Page 129
5.5 DSP Controls
Several Digital Signal Processing features are available in those IQ P.I.P. models with DSP capability like the IQ–
P.I.P.–DSP. They can be configured from a special DSP Sub-block screen or from a graphics plate. However, this
section will focus on controlling DSP from a DSP sub-block because it is a bit easier. To configure the DSP features
from a graphics plate you would create a control, assign a DSP parameter to it and then set the parameter.
Important: The DSP functions are
not disabled by the ASA control.
To switch to the DSP Sub-block screen, press & from the amplifier Control Block screen. An example is shown
below in Figure 5.13:
5.5.1 Signal Delay
A signal delay is available for each channel.
Delay: Sets the amount of signal delay in seconds. The range is 1.25 milliseconds (0.00125 seconds) to 0.175
seconds in 22.7 microsecond steps. (The minimum delay of 1.25 milliseconds is inherent in the DSP system.)
5.5.2 Programmable Filters
Each channel can have as many as eight different cascaded filters (the actual number depends on the mix of filters
chosen and the total number of required filter cells). There are seven different filter types from which to choose.
Each channel has a total of eight “biquad” filter cells. Note: “Biquad” refers to the double quadratic equations
which mathematically describe each filter implemented in the digital signal processor. The 1st and 2nd-order
filters each require one biquad filter cell. The 3rd and 4th-order filters each require
two biquad filter cells. This
means that a channel can have no more than four filters if they are all 3rd or 4th-order filters. Remember that only
eight filter cells are available—this limits the total number of filters that a channel can have. An error message will
be reported by the IQ software if this capacity is exceeded.
A description of the filter controls is presented next:
Fig. 5.13 An Amplifier DSP Sub-block Screen