HARMAN KARDON BU-120
Service Manual

Amplifier/Subwoofer

BU-120/HTS-20

When using a single subwoofer, you MUST use a pair of stereo low-level leads from your preamplifier's outputs. When using two subwoofers, one for the left and another for the right channels, connect the left preamplifier output to BOTH the left and right LOW-LEVEL INPUTS of the subwoofer used for the left channel by using a Female-to-Male �Y� connector at the subwoofer's output. Connect the right-channel preamplifier output to both jacks of the right-channel subwoofer in the same manner (See Figure 3). If the preamplifier has a mono subwoofer output, you'll also need a Male-to-Female �Y� connector to split the mono signal to the subwoofer pair (See Figure 3).

Figure 3. - Use this method when using a single subwoofer output or two subwoofers.

The subwoofer may be connected to your system using the HIGH-LEVEL INPUTS (4) on the plate located on the rear panel of the subwoofer. Use speaker wire, maintaining proper polarity (+ to + and - to -). Attach the speaker wire to the left and right HIGH-LEVEL INPUTS on the subwoofer and the other ends to the proper left and right OUTPUTS on your amplifier or receiver (See Figure 4). If you plan to use two subwoofers (one for the left and the other for the right channel), connect wires from the left and right OUTPUT on your power amplifier or receiver and attach the other ends to the corresponding HIGH-LEVEL INPUTS on each subwoofer. Observe polarity (See Figure 4).

Figure 4. - Use this method when using a single
subwoofer.

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