Connecting a radio to a speaker requires more thought than just connecting the wires. A radio has an output impedance just like a speaker that has an input impedance. To transfer maximum power from the radio to the speaker, the impedance of the radio and the impedance seen at the speaker must be equal or as close to equal as possible. It is very difficult to change the radio impedance, but the speaker impedance can be changed by adding or subtracting speakers in various configurations.
Instructions
1. Verify the impedances of the radio and speakers by checking the manufacturer's documentation. In this example, the radio has an output impedance of 8 ohms, and the speakers have an input impedance of 4 ohms.
2. Strip 1/2 inch of insulation off of the ends of the speaker wire. Connect the positive terminal of one of the radio output terminals to the positive terminal of speaker #1. Connect the negative terminal of the radio output terminal to the negative terminal of speaker #2.
3. Take another speaker wire and connect the negative terminal of speaker #1 to the positive terminal of speaker #2. Since the radio has an impedance of 8 ohms, 8 ohms is the impedance needed at the speakers. In order to get 8 ohms at the speakers, they have to be wired in series so the impedances add together to produce an 8-ohm impedance.
Tags: radio output, terminal speaker, impedance ohms, negative terminal, positive terminal