Loudspeakers can be categorized into passive and active speakers. Passive speakers are without an amplifier and connect to a power amplifier via speaker cable. In contrast, active speakers have a built-in amplifier. Chances are that you active speakers do not work with mains power. That is because if speakers can be connected to mains power, they have to be subject to safety approval. Such approval takes time and is also fairly expensive.
Also, there are many different types of power connectors used in different countries. Therefore it is difficult for manufacturer to produce a product which is usable in each country. Therefore usually manufacturers will not design their speakers to accept mains voltage but rather a low voltage. In this post, I will show you how you can choose an appropriate power supply.
Wireless speakers also are to be considered active speakers. However, usually the manufacturer will bundle the power supply with the speakers so you don’t have to go out and get one. In either case, if you want to purchase a power supply the first thing you will have to notice the voltage and current requirement of speaker. Some speakers only give the voltage without current. If that is the case you might want to ask the manufacturer or retailer. If neither of those will give you an answer then you can just do some simple math. Just figure out the wattage of the speaker. This wattage is usually given the specifications.
Once you know the wattage, simply divide this number by the power supply voltage. That will give you the current that speaker will consume. Both the voltage and current rating a crucial when picking a power supply. Also, make sure that you note what type of connector is required. There different standards of power connectors available. Obviously, the power supply must fit the speaker. Another thing to note besides the voltage and current rating is to polarity. There are power supplies that have plus on the inside and ground on the outside. However, they also power supplies with reverse polarity. Connecting the wrong power supply to you speakers can actually caused some damage.
I would recommend purchasing a switch mode power supply. These power supplies consume less power than linear power supplies and are much smaller. Just note the voltage and current when you purchase the power supply and obviously also the polarity. To be on the safe side, I recommend testing the voltage of the power supply with a voltmeter before you connect the power supply with speakers. That will keep your speakers safe.