FIR Designer M : Channels – Import
The Channels system tab contains the complete filtering design workflow from loudspeaker measurement import through to IIR and FIR export. The sub-tabs match are similar to FIR Designer and FIR Designer 2, but also enable viewing of the responses of all channels and the combined system response.
|Edit Channel||Use the drop-down to select the output channel to be edited.|
|Include in Combined||When checked, the channel response is summed into the combined System response. Sometimes it is helpful to remove a channel from the Combined response, such as when designing a 2-way system which will be loaded into the Lake FIR 3-way module. In this scenario, set the System number of channels to 3 but uncheck Include in Combined for the 3rd channel. (The 3rd channel can be muted in the Lake Controller after loading.)|
|Hide phase||When checked, phase response data, for frequencies outside the < and > range, is not displayed.|
|<||When this is set to a number (in Hz), phase plots don’t display phase data below this frequency. To show all phase data, set to the minus symbol or ‘-‘ (without the quotes).|
|>||When this is set to a number (in Hz), phase plots don’t display phase data above this frequency. To show all phase data, set to the minus symbol or ‘-‘ (without the quotes).|
Import a loudspeaker measurement using the Load button. See also Import File Formats.
The Clear button removes any loaded measurement, sets the response to an impulse and sets all Speaker Response controls to defaults.
|Normalise magnitude to max||When checked, the level of the measurement is adjusted so that the peak or maximum of the measurement is 0 dB. Also, the gain required to bring the peak to 0 dB is displayed in the edit field below.
When unchecked, gain can be manually entered in the edit field below.
|Magnitude offset (dB)||When Normalise magnitude to max is unchecked, enter a gain value (in dB) in the edit field to manually move the level of the loudspeaker response.|
|Oct smoothing||Use the drop-down to select smoothing to be applied to the loudspeaker measurement.|
|Magnitude: Complex or Power||When Oct Smoothing is not set to None, the smoothing can be calculated from complex spectral values, or power values (and ignoring phase).|
|Use Coherence||When Oct Smoothing is not set to None, the smoothing can take into account coherence but favouring spectral values with higher coherence.|
|Delay (samples)||Here the measurement delay can be adjusted, in quarter sample increments (at the output channel sample rate from the System Setup tab).|
|Find Peak||This button moves the maximum positive peak in the measurement impulse response to time=0.|
|+ and –||These buttons increment and decrement the measurement delay in quarter sample increments (at the output channel sample rate from the System Setup tab).|
|Flip polarity||If this is checked, the measurement is inverted.|