Speaker Polarity and Phase Basics
Polarity refers to the position of the “positive or hot” (+) and the “negative or common” (–) signals in an audio system. It’s the part of the signal (waveform) that is currently “active.” Some connectors will designate which pin is hot and common, and some connectors may also designate a “ground” where the shield wire should connect. Speakers will usually have red and black connectors, markings, or dots on them to designate polarity (refer to the images below).
Speaker / Amplifier Polarity Notes
When speakers are connected “In Polarity,” the speaker cones will move “in and out” at the same time, when this occurs, the speakers are said to be in correct polarity (in phase). When speakers are not connected “in phase” this can cause signal cancelations. This is why it is very important to check for the red / black connectors, any markings (plus, negative symbols), or simply a small red dot next to positive prior to hooking up your speakers.
Here are some additional examples of markings (plus and minus), symbols, and dots on various pieces of audio equipment and speakers.
Important Technical Note: You should always maintain proper signal polarity starting with the inputs, and continuing all the way to the outputs in your sound system.
What does it mean to be “In-Phase?”
In the example below, when two signals are 180 Degrees
“Out of Phase” the two signals cancel each other out. Sometimes the signal can be completely cancelled out, and sometimes the signal can just sound “attenuated” (lower in signal level).
