Installing a pair of loudspeakers is usually fairly easy. However, if you have a large living room then you might want to consider setting up additional speakers around the perimeter of your room. If you only used to speakers then you will have to crank up the volume on them significantly. This high volume can damage the speakers and also will be annoying for people who were close to the speakers. To provide for a much better and more even distribution of the sound in your home, you should set up multiple speakers.
When setting up additional speakers, make sure that the amplifier supports connecting of multiple speakers. Preferably you would want to have a dedicated amplifier for each speaker. You might even want to consider purchasing a surround sound receiver. These receivers have multiple amplifiers. You can then set the amplifier to take a simple stereo signal and output it on to each channel. However, note that not all AV receivers are that up in a way that allows you to stream stereo audio through multiple speakers.
As an alternative, you might want to purchase a small amplifier for each speaker. The amplifier can be located behind on top of the speaker. Then you will connect the output of each amplifier with each speaker terminal by using a short speaker wire. The speaker wire might already be included with the amplifier. Then all you need to do is provide audio to each amplifier input. In this scenario, each amplifier needs power. So make sure that you have an outlet near each amplifier.
Sometimes you can also connect multiple loudspeakers in parallel and thus avoid having to spend money for purchasing multiple audio amplifiers. However, keep in mind that the impedance of the speaker will be reduced if you connect multiple speakers in parallel. Make sure that you amplifiers able to handle the speaker load. Also, keep in mind that the wattage of each amplifier is split between multiple speakers. Therefore I don’t usually recommend the setup.