APPENDIX
WIZARD
The FIR Wizard is a smart and easy-to-use software tool designed for enhancing the audio quality
of a loudspeaker by compensating the linear distorsions, both in magnitude and phase, through FIR
filtering.
The tool guides the user through the loudspeaker IR measurement and allows generating state of
the art equalization FIR filters, with few essential synthesis parameters, that “invert” unwanted
phase shift, with the aim to linearize the phase response of the loudspeaker.
A magnitude equalization option is also available, allowing to flatten the amplitude response of the
loudspeaker, or to set up a target magnitude curve.
Moreover, the Wizard allows to reduce the nominal latency of the generated FIR filter, in such way
to fulfill the latency constraint of live sound systems, while preserving, almost unchanged, the
correction capability of the filter itself.
Preliminary
The FIR Wizard is a tool to aid the user in “optimizing” the response of a loudspeaker, but driver
choice as well as good cabinet and Xover design still remain the primary steps to achieve the best
sound quality.
In general, before using the FIR Wizard, the user should do all the needed steps to correctly setup
its sound system and to start from a reasonable loudspeaker response.
For example, in a multi-way loudspeaker, the response of each driver should be aligned in time to
avoid dips in the Xover point, that can not be filled by FIR filtering without introducing audible
artifacts.
Moreover, a preliminary coarse loudspeaker equalization is required to start from an almost flat
overall frequency response, especially when FIR filtering is used to compensate both magnitude and
phase. This allows to avoid strong boost of some frequencies, that may introduce undesired audible
ringing effects.
If a non-flat target response is desired, the preferred procedure should be anyway to start from an
nearly flat response and apply a post equalization after computing the compensation FIR filter, or,
even better, to apply a target curve in the FIR filter itself.
Summary of Contents for LPP-480F
Page 1: ...User Manual LPP 480F...
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