********************** Inches to Ohms **************************

Basic acoustics tells us that an open baffle acts as a high-pass

filter with a cutoff frequency ( Fc ) defined by the formula :

Fc = 4560 ( Hz ) / baffle-diameter ( inches )

Basic electronics defines the cutoff frequency of a R C

( resistor - capacitor ) high-pass filter with the formula :

Fc = 1 ( Hz ) / ( 2 pi * r ( Ohms ) * c ( Farads ) )

Therefore since Fc = Fc :

( 4560 / diameter ) = 1 / ( 6.28 * r * c )

Converting inches to Ohms :

( 4560 / r ) = ( 1 / ( 6.28 * r * c ) )

4560 = ( 1 / ( 6.28 * c ) )

( 1 / 4560 ) = 6.28 * c

c = 1 / ( 4560 * 6.28 ) = 1 / 28637 = 35 uF

Ergo :

To simulate an open baffle using electronics software we may

use a R C highpass filter where C = 35 uF and R = baffle diameter

( in inches )

Example : 8 inch bare driver

Basic acoustics tells us that an open baffle acts as a high-pass

filter with a cutoff frequency ( Fc ) defined by the formula :

Fc = 4560 ( Hz ) / baffle-diameter ( inches )

Basic electronics defines the cutoff frequency of a R C

( resistor - capacitor ) high-pass filter with the formula :

Fc = 1 ( Hz ) / ( 2 pi * r ( Ohms ) * c ( Farads ) )

Therefore since Fc = Fc :

( 4560 / diameter ) = 1 / ( 6.28 * r * c )

Converting inches to Ohms :

( 4560 / r ) = ( 1 / ( 6.28 * r * c ) )

4560 = ( 1 / ( 6.28 * c ) )

( 1 / 4560 ) = 6.28 * c

c = 1 / ( 4560 * 6.28 ) = 1 / 28637 = 35 uF

Ergo :

To simulate an open baffle using electronics software we may

use a R C highpass filter where C = 35 uF and R = baffle diameter

( in inches )

Example : 8 inch bare driver

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