Multi-channel audio has become mainstream and manufacturers have developed many types of basic and more advanced technologies like wireless surround speakers, virtual surround sound to simplify the setup of home theater systems. I will review the latest trends to see which products in fact work. I will also give some advice for picking the perfect components. The majority of today’s TVs will be set up as a multi-channel audio system. Whereas historically TVs would come with built-in stereo loudspeakers, nowadays a number of external speakers are used to let the viewer experience surround sound. The most commonly used 5.1 surround sound format requires installing a total of 6 loudspeakers. These are one center speaker, two front side speakers, two rear speakers and a subwoofer. The newer 7.1 standard raises this number to 8 by adding two extra side speakers.
Thus installing a home theater has become quite hard and long speaker cable runs are normally undesirable for aesthetic reasons. Part suppliers have designed various technologies to simplify the installation.
The first option is building so-called virtual loudspeakers (find extra information here on the subject of wireless home theater speakers) by applying signal-processing to the audio and introducing phase shifts and special cues to those audio components that would ordinarily be sent by the remote speakers. The signal processing is engineered based on how the human hearing determines the location of a sound. The audio signal is then broadcast through the front loudspeakers. Due to the signal processing, the viewer is tricked into assuming the audio is coming from virtual remote surround loudspeakers. Virtual surround eliminates the remote speakers and simplifies the setup and also avoids long speaker cord runs. However, it also has a disadvantage. The form of each human’s ear is slightly different. As a result everybody processes sound in a different way. Since the signal processing is based on a standard human ear model, virtual surround will not work equally well for everybody dependant upon how much the viewer varies from the standard model.
Wireless surround sound products are one more method for simplifying home speaker installations and normally include a transmitter module which connects to the source in addition to wireless amplifiers that will connect to the remote speakers. This transmitter will typically provide line-level in addition to amplified speaker inputs. Ideally it should have a volume control to adjust it to the audio source. Some wireless speaker systems are designed to connect 2 loudspeakers per wireless amplifier. A superior solution would come with a wireless amplifier for every remote loudspeaker to get rid of the cord runs between each of the 2 remote speakers. The most sophisticated wireless systems utilize digital transmission to avoid signal degradation. To be certain that all loudspeakers are in sync in a multi-channel application, make certain that you choose a wireless system which has an audio latency of just a few milliseconds at most. A large latency would lead to an echo effect. This effect would degrade the surround effect. Most wireless gadgets operate in the 900 MHz and 2.4 GHz frequency bands. Some products use the less crowded 5.8 GHz frequency band and therefore have less competition from other wireless products. Another option are side-reflecting loudspeakers. These systems are also named sound bars. There are additional speakers located 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 originating from besides or behind the viewer. The result by and large depends on the shape of the room and interior design and not work well in many real-world scenarios resulting from different room shapes and obstacles in the room.