Rockford Fosgate PWR-410, PWR-815, PWR-812, PWR-810 C A L C U L At I N G L O A D I M P E D A N C E

after the amplifier and separates the signal fed to each speaker in the system. Active crossovers offer the accuracy and flexibility needed for a sophisticated system and are used in complex multiple amp designs. Passive crossovers (capacitors and inductors) allow the use of mul- tiple speakers in a simple system which can easily be expanded over time. We recommend using a 6dB per octave, 100Hz low-pass crossover for the Punch Power Woofers when used with a passive system.

To customize the installation, try adjusting the crossover point one octave up or down to optimize the system staging.

C A L C U L AT I N G L O A D I M P E D A N C E

The Punch Power Woofers are used for the sub-bass region, those frequencies below 100Hz. This is the foundation for the music and the frequency range you feel. Before selecting the passive crossover it is necessary to calculate the load impedance of the speaker system. In a series circuit the impedance is determined by the formula:

Rt = R1 + R2 + R3 + etc.

In a parallel circuit the impedance is determined by the formula:

1	=	1	+	1	+	1	+	1	+ etc.
Rt						R3
		R1		R2				R4

Where Rt is the total speaker load and R1, R2, etc. represent each speaker in the system.

The crossover is connected in line to the positive terminal of the speaker system. The crossovers are available from Authorized Rock- ford Fosgate Dealers.

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