Complementary Linear Phase Crossovers
in FIR Designer & FIR Designer M
Before & after complementary crossover generation
Linkwitz-Riley crossover filters (and less common Neville Thiele notched crossovers) are specifically designed so that low-pass and high-pass filters sum to a flat response with matched phase behaviour. However, other low-pass and high-pass IIR crossover filters don’t sum to unity and don’t have matched phase (for example, Bessel & Butterworth filters).
FIR Designer can mimic an IIR crossover filter’s magnitude response as a linear-phase FIR filter, and generate a complementary linear-phase high-pass or low-pass linear-phase FIR filter. The resulting low-pass and high-pass filter pair maintains a perfectly flat, summed magnitude response, along with matched, linear phase.
This functionality delivers flexibility in crossover design, enabling a much wider range of crossover characteristics to be used in multi-way loudspeaker designs, beyond the more limited set of crossover types that naturally sum correctly.
Check box selection for complementary crossover generation
Complementary crossover generation is supported for these filter types:
– Bessel
– Butterworth
– Chebyshev Type I
– Chebyshev Type II
– Elliptic
FIR Designer also includes a range of linear-phase brick-wall crossover filters for applications requiring extremely steep crossover slopes and maximum band separation.
