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FIRplayWondering about the advantages and disadvantages of FIR filters? This article will explain how to play with FIR filters and look at them with Smaart v7 within the confinements of your computer.

In order to make use of these solutions please consult Daniel Lundberg's instruction manual to setup you computer.

For an excellent primer on FIR filters read Pat Brown's ProSoundWeb article.

The program used for generating the FIR filter WAV files is a Windows application called rePhase by Thomas Drugeon.

The convolution plug-in for measuring the FIR filters in AU Lab is LAConvolver by (Tobias) Lernvall Audio.

inverse 2nd order APF in rePhasefigure 1ideal subwoofer in rePhasefigure 2AU Lab with LAConvolver plug-infigure 3inverse 2nd order APF in Smaart v7figure 4ideal subwoofer in Smaart v7figure 5Create your desired FIR filters in rePhase like e.g. an inverse (maximum phase) 2nd order all-pass filter (figure 1) or an ideal (linear phase) subwoofer (figure 2) and export them as 24 bits 48 kHz LPCM mono WAV files. Open a WAV file in the LAConvolver plug-in and turn off gain compensation (figure 3).

Figures 4 and 5 show the results in Smaart v7.

More examples are to follow.