Multi-channel audio has become mainstream and vendors have developed many types of basic and more sophisticated technologies including wireless surround sound speakers, virtual surround sound to simplify the setup of home theater kits. I will look at various of the latest technologies which were designed to make installing home theater systems a breeze. I will point out what to look out for when making your buying decision.
Traditionally, installing a TV would be swift since they would already come with built-in stereo speakers. This, though, has all changed with multi-channel sound. Today external speakers are utilized to create a surround sound effect. As the traditional 5.1 format needs 6 speakers: a front center, two front side speakers, two rear speaker and a subwoofer, the more recent 7.1 format adds two additional side speakers.
For that reason, home theater installations have become fairly complicated. Running wires to remote loudspeakers also is often undesirable because of aesthetic reasons. A number of technologies have emerged to simplify this process.
The first option is called virtual surround sound. This technique will take the audio components which would normally be sent by the remote speakers. It then applies signal processing to those components and inserts special cues and phase delays. Next 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 through the front speakers. The viewer is in effect deceived into believing the audio is coming from a location other than the front speakers.
Virtual surround eliminates the remote loudspeakers and simplifies the installation and also avoids long speaker cable runs. Then again, it also has a drawback. The form of each human's ear is a little dissimilar. Therefore everybody processes sound differently. 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.
An alternative method for eliminating long speaker cable runs is to utilize wireless surround sound products or wireless speakers. A wireless product contains a transmitter and one or several wireless amplifiers. The transmitter connects to the source. The wireless amplifiers connect to the remote speakers. Normally the transmitter component will have amplified loudspeaker inputs and line-level inputs. This offers flexibility to connect to every type of source. A transmitter volume control helps take full advantage of the dynamic range and eliminates clipping of the sound within the transmitter.
A number of wireless speaker systems are designed to connect 2 loudspeakers per wireless amplifier. A superior solution would provide a wireless amplifier for each remote speaker to get rid of the wire runs between each of the 2 remote speakers. The most basic wireless devices use FM transmission. FM transmission is susceptible to noise and audio distortion. More advanced products make use of digital audio transmission to completely maintain the original audio. Be certain that you pick a wireless system with a low audio latency, at most a few milliseconds. This will make certain that the sound from all loudspeakers, including the non-wireless speakers, is in sync. Low latency is also important for good sync with the video. 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. A few products also use the 5.8 GHz band. These devices have less competition from other wireless devices than products using the crowded 900 MHz or 2.4 GHz bands.
A third technology employs side-reflecting speakers. This solution is named sound bars. The sound that would ordinarily be sent by the remote speakers is instead broadcast by loudspeakers at the front. These front loudspeakers broadcast the sound at an angle. Then the audio is reflected by the side and rear walls and appears to be originating from besides or behind the viewer. The result heavily is dependent upon the interior, in particular the shape of the room and the decoration. It will function well for square rooms with no obstacles and sound reflecting walls. However, realistic scenarios frequently will be different from this ideal and diminish the result of this solution.