Calculate 2 Way 1st Order Linkwitz-Riley Crossover
For optimal filter operation it is important to use the impedance (Z) of the loudspeaker at the cut-off frequency.
The DC resistance is NOT optimal to calculate crossover filters!
The huge problem with first-order filters is that cut-off slope isn't
very steep; indeed, it's shallow, falling off at only -6dB per octave
and -20dB per decade. This requires that the both drivers exhibit much
wider bandwidth than we are likely to encounter in reality.
