FIR Designer M : System Target

The overall system target response – both magnitude and phase – can be set on this view.

Each channel also has a channel target response. For each channel, the system target response is combined with the channel target response to create the final target used for the channel. So, for example, the system target could be used to specify the desired system response and the channel targets used for crossover responses.

Preset

Target settings can be stored in a target preset file that has the extension *._tp.

Use the Load and Save buttons to open and store a preset. The Reset button sets all target settings to defaults.

Target Tab Controls

The target magnitude and phase response is created as the sum of four different methods.

Curve

The broad magnitude response can be defined using slope segments and a bass shelf. For each segment, the Start Freq denotes the knee point above which the slope takes effect, and the dB/oct denotes the slope. (The number of segments is unlimited.)

The  Smoothing (oct) drop-down sets the smoothing used to soften the transitions between slope segments and between the bass shelf and the first slope segment.

Mag

Common magnitude prototype filters can be used to shape the target response. Each individual filter prototype can be set to minimum, linear or maximum phase. Note that minimum and maximum phase filters inherently impart a phase change and move the target response away from 0 degrees. (The number of filter prototypes is unlimited.)

Phase

1st and 2nd order all-pass filter prototypes and a unique 4th order parametric all-pass filter prototype can be used to shape the phase of the target response. 1st and 2nd order all-pass filters can be set to minimum or maximum phase. (The number of filter prototypes is unlimited.)

File

A response – either a FIR filter or another loudspeaker measurement – can be loaded from file. The tab includes options to use only the magnitude or phase, adjust the response level, apply smoothing, invert or flip polarity, and adjust the time alignment.

Total Target Response plot

This plot shows the magnitude and phase for each tab and for the combined system target response.