Radio Shack MPA-50 owner manual Speakers in Parallel, Series and Parallel Combined

32-2002.fm Page 9 Friday, February 11, 2000 11:36 AM

Speakers in Parallel Series and Parallel Combined

Two 8Ω Speakers

1.To determine the total impedance of speakers connected in parallel, divide the impedance of one speaker by the number of speakers.

For example, if you want to connect two 8-ohm speakers in parallel, divide 8 (the impedance of one speaker) by 2 (the number of speak- ers) for a total speaker impedance of 4 ohms.

2.Connect the speakers’ negative (–) terminals together.

3.Connect the speakers’ positive (+) terminals together.

4.Connect the speakers’ negative (–) terminals to the amplifier’s COM ter- minal.

5.Connect the speakers’ positive (+) terminals to the amplifier’s terminal

that matches the total speaker impedance (4Ω, in this example).

Four 8Ω Speakers

If you must hook up more than two speakers, you might have to use a com- bination of series and parallel connec- tions to get a total impedance that matches one of the amplifier’s terminals.

If you connect four 8-ohm speakers in series, the total impedance is 32 ohms (8 + 8 + 8 + 8 = 32). This exceeds the maximum rating.

If you connect these speakers in paral- lel, the total impedance is 2 ohms (8 ⎟ 4

=2). This falls below the minimum rat- ing.

You can arrive at a proper total imped- ance by combining series and parallel connections.

1.Group speakers into pairs.

2.Connect each pair of speakers in series.

For example, the total impedance of each pair of 8-ohm speakers is 16 ohms (8 + 8 = 16).

3.Connect the pairs of speakers in parallel.

Speakers 9