Home Cinema Theater – Surround Sound Problems?


You have just acquired your brand new home cinema theater system, spending not too little. There is great picture, a superb speaker, amazing speakers and you are ready for the final touch, to start watching your favourite films; connect the rear channel surround speakers. Not so amazing and great, is it? And all the wires all over the place will definitely make you regret buying your home theater. Well, here is when wireless comes along. Not so fast… There are a few aspects which you haven’t though that will most probably cause some unpleasantness when you connect wireless to surround sound.

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One of them is the time lag. There is a required time for the transmission and processing of the sound from the rear speakers to the front speakers. In order to generate the signal, transmit it to the speaker, decode it and at the end amplify it from the speakers is a certain process. For you to enjoy surround sound there must be a latency in processing, to prevent the case where the sound comes in different time from the front and rear speakers. And that is the case because you usually have the rear channels nearer to the viewer digital cinema. To avert this situation systems like Dolby Digital and Dolby Surround Pro Logic enforce a certain delay of milliseconds for the different surround sound channels.

It is vital that when you hear the sound to cannot say exactly where the source of the sound is placed. This creates an illusion that gives depth to the sound field. And for that reason, engineers use balance controls to imitate sounds across the sound field so that we pick out sounds from various locations. Time is the most vital aspect in surround sound since it can determine how sound reaches our ears and then our senses in general. 

Another problem is interference. The source of the interference in each system is according to the technology used.

Different systems use different ways to avoid interference. For example, Bluetooth believes that when the signal gets interference it will sense it and simply change the frequency. Wi-Fi also believes that it can solve the interference issues by shifting channels. These products, however, have limited potential because of the 802.11 chipsets and the protocol they follow.

Infrared or IR technology is used for wireless surround. It has the potential of more than 100 Mbps and that is why it has been very prevalent. The defect is that it needs a direct line of sight (LOS) and whenever this connections is not achieved the signal is lost along with the sound.  

Moreover, you may need to face the problem of power. The rear speakers will most probably need power source if they receive the signal without any wires. And if the non-existence of wires was the main point at first then this means trouble. Powercast uses a technology that can provide with power wireless devices but doesn’t have the ability to support wider needs, like these of surround channels.  

It of great importance to read the attributes carefully when buying a device. You need to make sure that when it says wireless they actually mean it and have solved the above issues.

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