Multi-Sub Optimizer Tutorial (page 6)
Setting Default Filter Parameter Limits
MSO is initially set up with default values for the minimum and maximum parameter limits. These limits prevent the optimizer from adjusting parameters to values that are either impractical or beyond the capability of your DSP hardware. You can change these limits using the Application Options dialog. From the main menu, choose Tools, Application Options. The Application Options dialog will be shown as below.
Assume the DSP being used has a maximum delay of 15 milliseconds. Check the Use custom value for minimum allowable delay checkbox and enter 0 into the Minimum delay, msec edit control. Check the Use custom value for maximum allowable delay checkbox and enter 15 into the Maximum delay, msec edit control. Now all newly-created delay blocks will have these limits for the delay. You can override the limits manually after the delay block is added, by using values as low as -60 milliseconds for the lower limit and as high as 60 milliseconds for the upper limit. A negative delay means that the delay should be reduced relative to the as-measured condition, which means increasing the sub distance in your AVR from what it was when the measurement was performed.
You can configure custom minimum and maximum values for each of the parameters of other filter types too, but for this tutorial you'll keep all of them at the default values except the minimum and maximum delays. These values will stay in effect for all projects, not just the current one. Changes you made to the default minimum and maximum delays affects only newly-created delay blocks.