Apr 062012
 

Setting up multi-channel audio such as a home theater system has always been relatively difficult and manufacturers lately have developed unique products and technologies including wireless surround sound systems products or virtual surround sound to help simplify this procedure. I will look at several of the most recent technologies that were designed to make setting up home theater systems a breeze. I will highlight what to look out for when making your buying decision.

Most of modern TVs will be installed as a multi-channel audio system. As traditionally TVs would contain built-in stereo speakers, these days a number of external loudspeakers are used to allow the viewer experience surround sound. The most commonly used 5.1 surround sound format requires setting up a total of 6 loudspeakers. These are one center speaker, two front side speakers, two rear speakers and a subwoofer. The more recent 7.1 standard increases this number to 8 by adding two additional side speakers.

As a result the setup of home theater kits has turn out to be a fairly complicated process. Numerous houses are not pre-wired for surround sound. Moreover, long speaker cables are often unattractive. A number of technologies have emerged to simplify this procedure.

The first method is named virtual surround sound. This solution will take the audio components which would ordinarily be broadcast by the remote loudspeakers. It then applies 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 next sent by the front loudspeakers together with the front speaker audio components. The signal processing is modeled after the human hearing. It uses the information about how the human ear can determine the origin of sound. Because of the signal processing, the viewer is deceived into thinking the sound is coming from virtual remote surround speakers.

Virtual surround eliminates the remote speakers and simplifies the setup and also eliminates long speaker wire runs. Then again, it also has a downside. The form of each human’s ear is somewhat dissimilar. As a result everybody processes sound differently. The signal processing is based on measurements which are done using a standard human ear model. If the form of the ear changes, sound will travel differently. As a result virtual surround will not function equally well for everyone.

Wireless surround sound products are one more approach for simplifying home speaker installations and normally include a transmitter component which connects to the source in addition to wireless amplifiers which will connect to the remote loudspeakers. The transmitter will normally come with amplified speaker inputs along with line-level inputs and come with a volume control to adjust it to the source audio level.

A number of wireless speaker devices are designed to connect 2 loudspeakers per wireless amplifier. A better solution would come with a wireless amplifier for each remote speaker to eliminate the cord runs between each of the 2 remote loudspeakers. The most advanced wireless systems utilize digital transmission to avoid signal degradation. Make sure that you choose a wireless system with a low audio latency, at most a few milliseconds. This will guarantee that the audio from all loudspeakers, including the non-wireless speakers, is in sync. Low latency is also vital for good sync with the video. A large latency would lead to an echo effect. This effect would degrade the surround effect. Many wireless gadgets operate in the 900 MHz and 2.4 GHz frequency bands. Some products utilize the less crowded 5.8 GHz frequency band and consequently have less competition from other wireless gadgets.

Another option are side-reflecting loudspeakers. These models are also named sound bars. There are extra loudspeakers positioned at the front which broadcast the sound for the remote speakers from the front at an angle. The audio is then reflected by walls and seems to be coming from besides or behind the viewer. The effect heavily is dependent upon the interior, particularly the shape of the room and the decoration. It will work well for square rooms with no obstacles and sound reflecting walls. However, realistic scenarios often will differ from this ideal and reduce the effect of this approach.

You can find additional details regarding 5.1 wireless surround sound kits as well as other surround sound types at Amphony’s website.

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