The majority of today's TVs will be installed as a multi-channel audio system. Whereas traditionally TVs would have built-in stereo loudspeakers, today a number of external loudspeakers are used to allow the viewer experience surround sound. In case of 5.1 surround, 6 speakers are utilized: center, left and right front, left and right rear and a subwoofer. Newer 7.1 systems need a total number of 8 speakers by adding 2 extra side speakers.
For that reason, home theater setups have become rather difficult. Running wires to remote speakers also is often undesirable due to aesthetic reasons. Suppliers have recently introduced new products and technologies. These devices were created to help simplify the setup of home theater systems.
The first option is named virtual surround sound. This solution will take the audio components which would typically be broadcast by the remote speakers. It then utilizes signal processing to those components and inserts special cues and phase delays. Then these components are mixed with the front speaker audio. The audio is then broadcast by the front loudspeakers along with the front speaker sound components. The signal processing is modeled after the human hearing. It utilizes the information about how the human ear can determine the source of sound. The viewer is in effect deceived into assuming the sound is originating from a location other than the front speakers.
The advantage of this technology is that only a small number of speakers are needed and no long speaker cable has to be run throughout the viewing environment. The drawback however is that each human will process sound differently as a result of the different form of each human ear. The signal processing of these virtual surround systems is based on a standard model which was measured with a standard ear. However, virtual surround will not work equally well for each person.
One more option for simplifying home theater installations and avoiding long speaker wire runs is to use wireless surround sound products or wireless speakers. A wireless solution will normally incorporate a transmitter component that connects to the TV or source in addition to wireless amplifiers that will be connected to the remote loudspeakers. Usually the transmitter component will come with amplified speaker inputs and line-level inputs. This provides freedom to connect to every kind of source. A transmitter volume control helps take full advantage of the dynamic range and eliminates clipping of the sound within the transmitter.
Several wireless products come with wireless amplifiers that connect to two speakers. This still requires cable runs between the two speakers. Other products offer individual wireless amplifiers for every loudspeaker. Entry-level wireless systems employ FM transmission or audio compression that will degrade the sound quality to some degree. More sophisticated wireless systems utilize uncompressed digital audio broadcast. To be certain that all loudspeakers are in sync in a multi-channel application, make sure that you choose a wireless system that has an audio latency of a few milliseconds at most. A large latency would lead to an echo effect. This effect would deteriorate the surround effect. Wireless kits often utilize the 900 MHz or 2.4 GHz frequency band. Some products also utilize the 5.8 GHz band. These products have less competition from other wireless gadgets than devices using the crowded 900 MHz or 2.4 GHz bands.
Other product models use side-reflecting speakers. This method is known as sound bars. There are extra loudspeakers located at the front which broadcast the sound for the remote loudspeakers from the front at an angle. The sound is then reflected by walls and seems to be originating from besides or behind the viewer. The result by and large is dependent upon the shape of the room and interior design and not function well in a lot of real-world scenarios resulting from different room shapes and obstacles in the room.
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