First Order
6 dB/Octave Rolloff		 Second Order
12 dB/Octave Rolloff		 Third Order
18 dB/Octave Rolloff		 Fourth Order
24 dB/Octave Rolloff		 Sixth Order
36 dB/Octave Rolloff
Bessel C1 = 0.0912 / ( Rh * Fx )
C2 = 0.0912 / ( Rl * Fx )
L1 = 0.2756 * ( Rh / Fx )
L2 = 0.2756 * ( Rl / Fx ) 		C1 = 0.07911 / ( Rh * Fx )
C2 = 0.3953 / ( Rh * Fx )
C3 = 0.1897 / ( Rl * Fx )
L1 = 0.1317 * ( Rh / Fx )
L2 = 0.3294 * (Rl / Fx )
L3 = 0.06592 * ( Rl / Fx ) 		C1 = 0.0702 / ( Rh * Fx )
C2 = 0.0719 / ( Rh * Fx )
C3 = 0.2336 / ( Rl * Fx )
C4 = 0.0504 / ( Rl * Fx )
L1 = 0.0862 * ( Rh / Fx )
L2 = 0.4983 * (Rh / Fx )
L3 = 0.3583 * ( Rl / Fx )
L4 = 0.1463 * ( Rl / Fx )
Butterworth C1 = 0.159 / ( Rh * Fx )
L1 = Rl / ( 6.28 * Fx ) 		C1 = 0.1125 / ( Rh * Fx )
C2 = 0.1125 / ( Rl * Fx )
L1 = 0.2251 * ( Rh / Fx )
L2 = 0.2251 * (Rl / Fx ) 		C1 = 0.1061 / ( Rh * Fx )
C2 = 0.3183 / ( Rh * Fx )
C3 = 0.2122 / ( Rl * Fx )
L1 = 0.1194 * ( Rh / Fx )
L2 = 0.2387 * ( Rl / Fx )
L3 = 0.0796 * ( Rl / Fx ) 		C1 = 0.1040 / ( Rh * Fx )
C2 = 0.1470 / ( Rh * Fx )
C3 = 0.2509 / ( Rl * Fx )
C4 = 0.0609 / ( Rl * Fx )
L1 = 0.1009 * ( Rh / Fx )
L2 = 0.4159 * (Rh / Fx )
L3 = 0.2437 * ( Rl / Fx )
L4 = 0.1723 * ( Rl / Fx )
Chebychev C1 = 0.1592 / ( Rh * Fx )
C2 = 0.1592 / ( Rl * Fx )
L1 = 0.1592 * ( Rh / Fx )
L2 = 0.1592 * ( Rl / Fx )
Gaussian C1 = 0.0767 / ( Rh * Fx )
C2 = 0.1491 / ( Rh * Fx )
C3 = 0.2235 / ( Rl * Fx )
C4 = 0.0768 / ( Rl * Fx )
L1 = 0.1116 * ( Rh / Fx )
L2 = 0.3251 * (Rh / Fx )
L3 = 0.3253 * ( Rl / Fx )
L4 = 0.1674 * ( Rl / Fx )
Legendre C1 = 0.1104 / ( Rh * Fx )
C2 = 0.1246 / ( Rh * Fx )
C3 = 0.2365 / ( Rl * Fx )
C4 = 0.0910 / ( Rl * Fx )
L1 = 0.1073 * ( Rh / Fx )
L2 = 0.2783 * (Rh / Fx )
L3 = 0.2294 * ( Rl / Fx )
L4 = 0.2034 * ( Rl / Fx )
Linear-Phase C1 = 0.0741 / ( Rh * Fx )
C2 = 0.1524 / ( Rh * Fx )
C3 = 0.2255 / ( Rl * Fx )
C4 = 0.0632 / ( Rl * Fx )
L1 = 0.1079 * ( Rh / Fx )
L2 = 0.3853 * (Rh / Fx )
L3 = 0.3285 * ( Rl / Fx )
L4 = 0.1578 * ( Rl / Fx )
Linkwitz-Riley C1 = 0.0796 / ( Rh * Fx )
C2 = 0.0796 / ( Rl * Fx )
L1 = 0.3183 * ( Rh / Fx )
L2 = 0.3183 * ( Rl / Fx ) 		C1 = 0.0844 / ( Rh * Fx )
C2 = 0.1688 / ( Rh * Fx )
C3 = 0.2533 / ( Rl * Fx )
C4 = 0.0563 / ( Rl * Fx )
L1 = 0.1000 * ( Rh / Fx )
L2 = 0.4501 * (Rh / Fx )
L3 = 0.3000 * ( Rl / Fx )
L4 = 0.1500 * ( Rl / Fx ) 		C1 = 0.08841 / ( Rh * Fx )
C2 = 0.1081 / ( Rh * Fx )
C3 = 0.2188 / ( Rh * Fx )
C4 = 0.2947 / ( Rl * Fx )
C5 = 0.1783 / ( Rl * Fx )
C6 = 0.03979 / ( Rl * Fx )
L1 = 0.08594 * ( Rh / Fx )
L2 = 0.1420 * (Rh / Fx )
L3 = 0.6366 * ( Rh / Fx )
L4 = 0.2865 * ( Rl / Fx )
L5 = 0.2344 * ( Rl / Fx )
L6 = 0.1157 * ( Rl / Fx )
Legend:
FxCrossover Frequency
RhDC Resistance of Tweeter
RlDC Resistance of Bass Driver
Source: The Speaker Building Page.