Kenwood KAC-7251, KAC-7201 instruction manual Tri-mode, Example

■Tri-mode

CENTER UNIT

23

LL

R R

L

C

(High pass)

C

4

Subwoofer

(L + R) (Bridged)

●Principle of Tri-mode

Method of frequency band division using a coil and capacitor…in case of 6dB/oct. slope

	Crossover Frequency	Coil (L): Passes low frequencies and blocks high
0 dB			frequencies. (Low pass)
		Capacitor (C): Passes high frequencies and blocks low
-3 dB
				frequencies. (High pass)
L	C	C=	159000	(µF)
	Frequency		fc x R		fc=Cut of Frequency (Hz)
		L=	159 x R	(mH)	R=Speaker Impedance (	Ω	)
			fc

●Example:

When it is required to set a crossover frequency of 120 Hz using speakers with an impedance of 4 ohms.

Prepare commercially-available coil and capacitor with the closest ratings to the results calculated from the formula above. The capacitor rating should be as close as possible to 331.25 (µF) and the coil rating should be as close as possible to 5.3 (mH).

2CAUTION

•If you wish to bridge-connect a speaker, the speaker impedance must be no less than 4 ohms. Connecting a speaker with an impedance lower than 4 ohms may damage the unit.

•Be sure to connect capacitors to speakers to which high frequencies will be passed. Failure to do so will result in a drop of the combined impedance with the subwoofer.

•Ensure that the withstand voltage and current ratings of the capacitors (C) and coils (L) are sufficient.

English 11