Multi-channel audio has become mainstream and vendors have created many types of basic and more advanced technologies such as wireless surround sound speakers, virtual surround sound to simplify the installation of home theater kits. I will look at some of the products and technologies which have appeared and give some advice about choosing proper components for a hassle-free setup.

While in the past setting up a TV has been fairly easy, the emergence of multi-channel sound has made setting up home theater systems much more challenging by requiring a number of external speakers to create surround sound. In case of 5.1 surround, 6 speakers are utilized: center, left and right front, left and right rear and a subwoofer. More recent 7.1 systems require a total amount of 8 loudspeakers by adding 2 extra side speakers.

Therefore the setup of home theater systems has turn out to be a relatively complex procedure. Many houses are not pre-wired for surround sound. In addition, long speaker cables are often unattractive. Some technologies have emerged to simplify this procedure.

The first option is known as virtual surround sound. This method will take the audio components which would normally be sent by the remote speakers. It then uses signal processing to those components and inserts special cues and phase delays. Then these components are mixed with the front speaker audio. The signal processing is engineered according to how the human hearing determines the location of a sound. The audio signal is then sent by the front loudspeakers. Because of the signal processing, the viewer is tricked into believing the sound is originating from virtual remote surround loudspeakers.

This technology reduces the quantity of needed loudspeakers and eliminates long speaker cords but every human will process sound slightly differently due to the form of the ear. Since the signal processing is based on a standard human ear model, virtual surround will not function equally well for everybody dependant upon how much the viewer differs from the standard model.

Wireless surround sound products are an additional solution for simplifying home speaker setups and normally come with a transmitter module that connects to the source in addition to wireless amplifiers that will connect to the remote speakers. Customarily the transmitter part will come with amplified loudspeaker inputs and line-level inputs. This offers freedom to connect to any kind of source. A transmitter volume control helps maximize the dynamic range and eliminates clipping of the sound within the transmitter.

Some wireless kits have wireless amplifiers that connect to two loudspeakers. This still requires cord runs between the two loudspeakers. Other products come with individual wireless amplifiers for each loudspeaker. The most basic wireless kits use FM broadcast. FM broadcast is susceptible to noise and audio degradation. More sophisticated systems make use of digital audio transmission to completely maintain the original audio. In multi-channel audio kits, it is essential to pick a wireless option with a latency of only a few milliseconds. This will guarantee that the audio of all speakers is in perfect sync. A large latency would lead to an echo effect. This effect would degrade the surround effect. Some wireless systems work at 5.8 GHz which offers the benefit of less competition from other wireless products than devices employing the crowded 900 MHz or 2.4 GHz frequency band.

Another solution are side-reflecting loudspeakers. These kits are also called sound bars. There are extra speakers positioned at the front which broadcast the audio for the remote speakers from the front at an angle. The audio is then reflected by walls and appears to be coming from besides or behind the viewer. This method works best in a square room with minimum interior design and obstacles. It will not function well in many real-world scenarios with different room shapes though.