Series and Parallel Speaker Connections

Whenever connecting more than one speaker per channel to an amplifier, you must consider the way in which the amplifier will be impacted by adding the additional speaker(s). Additionally, speakers with dual voice coils also apply to this consideration. Two voice coils in a single speaker also cause different reactions from an amplifier depending on the way in which they connect to the amplifier.

The connection of more than one speaker per channel will make the amplifier run warmer. For the best sonic results, use one speaker per amplifier channel. If you must connect more than one speaker per channel, there are two methods in which to do so: Series and Parallel.

Series Connection

A series connection is established when voice coils are connected in a string – end to end – so there’s only one way for audio signals to flow “in” and only one way for audio signals to flow “out”. For example, if you were to series‐connect two speakers to the front right channel of the amplifier:

•The positive output terminal of the right channel connects to the positive input post of the first speaker.

•The negative input post of the first speaker connects to the positive input post of the second speaker.

•The negative input post of the second speaker connects to the speaker's negative output terminal of the right channel.

The total impedance of speakers in series is found by adding their impedances together. For example; two, four‐ohm speakers in series is an eight‐ohm load. Series connections are easier on the amplifier than parallel connections as the total impedance is higher than driving a single speaker.

An example of a SERIES connection between two speakers.