Wireless home theater speakers are a way of avoiding the need to have cables running all the way around your room in a multi-speaker setup. In most cases, only the rear speakers will be set-up wirelessly. When choosing speakers, you will need to consider whether to buy add-on units or a complete new speaker and receiver system.
It's important to note that, despite the name, wireless home theater speakers can actually have more cables than standard speaker systems. This is because each speaker requires some form of power. This can either be through a built-in amplifier, which must be connected to a power socket, or through an external amplifier, which is wired to both the power socket and the speaker. This means that it's usually possible to avoid lengthy cable runs by using wireless home theater speakers, but there can still be a lot of cabling involved, particularly if power outlets are not conveniently located for your chosen speaker sites. There are a few systems that are powered by batteries, but the performance is likely to be less impressive.
You will need to decide if you want to have all speakers be wireless, or merely some of them. In many rooms, somebody who wants to cut down on trailing wires may find that there is no problem with wired speakers at the front and center and that they only need wireless options for the rear speakers. The main advantage of doing it this way is that the costs are kept down, along with the need for power outlets. The disadvantage is that you will likely be left with different makes or models for the front or rear speakers. This may be a problem depending on your attitude to visual appeal or audio purity.
The main choice when choosing wireless home theater speakers is whether to buy add-on speakers or an integrated system. Add-on speakers involve a sender unit plugging into your existing receiver and sending the sound information to the speakers. If choosing this option, take care to check the connection options and make sure the send unit will fit a suitable socket on your receiver.
The other option is to buy a new system that comes with wireless speakers. This will of course be more expensive if you are replacing equipment, but can be a cheaper option than buying a new receiver and add-on speakers separately. Another benefit of an integrated system is that it may have adjustable settings which can correct any delay caused by the wireless transmission program. The main drawback is that there are fewer integrated systems available that will limit your choice and the degree of price competitions.
When choosing wireless home theater speakers, it's worth remembering that the technology is still developing. There is an argument that it is safer to get the cheapest speakers that give acceptable performance, which will make it more affordable to update your system in the future if and when better or different technologies emerge.