You might never have had to think about whether or not your speakers were AC or DC until you decided to put together a sound system. AC is an alternating current, and DC is a direct current. These two kinds of current cannot be used interchangeably, so knowing what kind of current your speakers need is critical.
Speakers use AC, but they are actually powered by an amplifier in most sound systems. The amplifier takes a DC power supply and converts the power to AC for the use of the speakers. Speakers will always be AC devices, no matter where you get them from or what style they are.
Are My Speakers Active or Passive?
There are actually two kinds of speakers. Active speakers are all-in-one units that have an amplifier built into them, while passive speakers are made to be used with an external amplifier that provides them with power. Both speaker types still use AC power, but the sound system that you are building will necessarily be different depending upon which kind of speakers you have.
Speakers are designed in largely the same way when it comes to the parts that make noise. The amplifier will offer you the chance to change the way that sound is produced via the speakers, and you will need to be sure that you are getting speakers that are capable of handling the power output of your amp. The efficiency rating of speakers helps predict how much they are capable of without being damaged during use.
Speakers can actually overheat due to the power that is being supplied to them and due to the volume at which they are playing music. While this is not related to current, it is related to the potential of your amp to create loud or varied sounds. You should be sure that you are connecting your speakers properly to your amp and that the speakers and the amp are going to be a good match. Without taking the time to do this, your speakers might be damaged during use.
Speakers Run on AC Power
All speakers will run on AC power. They cannot be used with DC power, and you should be sure that the amplifier that you have in your sound system is the right match for the speakers that you have purchased. Wearing out speakers is easy if you are making them get too hot while you are using them due to the power of the amp that you have selected.
You should also be sure that you are getting the right style of the speaker to produce the sound that you are looking for. The current will not have anything to do with their performance when it comes to sound quality. Everything about your sound quality is up to the match between the amp and the speakers and the capacity of the speakers themselves.