When you use more than one speaker to produce a common sound, the speakers will work with each other to make a sound field. In order for your music to sound balanced and correct, they all need to be wired in phase, or in the same polarity. If your speakers are out of phase, they will unavoidably cancel each other out and produce music that sounds dull and that lacks ordinary imaging. If only one speaker is out of phase, your music will not sound correct. Proper speaker phase is important in all applications, whether it be car audio, home audio, or pro audio.
Checking For Proper Speaker Phase
There are a few different ways to test your system for incorrect speaker polarity. The first way is to use a 1.2v or 1.5v AAA battery. Touch the positive end of the battery to your supposed positive wire lead to the speaker, than quickly touch the negative wire to the negative end of the battery for no more than a second. Please note, we do not recommend doing this with tweeters due to their small size and inability to handle such voltage. If when you touch both wire leads the driver pops outward, you know your speaker is in phase. If the cone moves inward, you will need to reverse the wires to your source unit or amplifier. The more practical and potentially less harmful way to test for proper speaker phase is with the use of a speaker polarity tester, such as the SoundGate PLR1. You may use either of these methods to test each individual driver for proper speaker phase.
Consider Testing Your Vehicle
When your speakers are out of phase, you will be losing a significant amount of quality when comparing to the potential that they can really offer. Consider checking your system for proper phasing to be sure you are getting the best sound possible out of your car audio system.