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High Pass Crossover Filter Schematic
Highpass Filter
To determine the crossover frequency a certain amount of capacitance will give you, use the formula:

0.159/(C x Rh) = F

Explanation of Terms
C - is the capacitance value (in Farads) - to convert to Farads divide the value shown on the side of the cap in uF by one million.
Rh - is the impedance of the load (speaker) you will be using.
F - is the crossover frequency you will get.

 

by frequency
Crossover Frequency (Hertz) Capacitance uF (microFarad)
8 Ohms 4 Ohms 2 Ohms
80 248.44 496.88 993.75
100 198.75 397.50 795.00
120 165.63 331.25 662.50
150 132.50 265.00 530.00
200 99.38 198.75 397.50
280 70.98 141.96 283.93
400 49.69 99.38 198.75
600 33.13 66.25 132.50
800 24.84 49.69 99.38
1000 19.88 39.75 79.50
1200 16.56 33.13 66.25
2000 9.94 19.88 39.75
4000 4.97 9.94 19.88
5000 3.98 7.95 15.90
6000 3.31 6.63 13.25
8000 2.48 4.97 9.94
10000 1.99 3.98 7.95
12000 1.66 3.31 6.63

 

by capacitor
Capacitance uF (microFarad) Crossover Frequency (Hertz) approximate
8 Ohms 4 Ohms 2 Ohms
2.2 9034 18068 36136
3.3 6023 12045 24091
4.7 4229 8457 16915
6.8 2923 5846 11691
10.0 1988 3975 7950
22 903 1807 3614
50 398 795 1590
100 199 398 795
200 99 199 398

 

Calculate for any Value
 To use this calculator, enter the amount of capacitance you have available in the first box. Then enter the impedance of the speaker you will be using with this filter in the box below that. Finally, click the "Calculate It" button to see the frequency this filter will be -3 dB.
Capacitor =  uF
Rh = Ohms
Answer =  Hertz
  

 

Capacitors in Series/Parallel
 To use this calculator, enter the amount of capacitance in the first two boxes, they can be different values - this is how you obtain the odd values in the charts above. Then pick a series or a parallel connection. Now, click the "Capacitance" button to see the resulting value.
Capacitor 1 =  uF
Capacitor 2 =  uF
Connection
ParallelSeries
Answer =  uF
  



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