You got the "Terminator 3" DVD and a 50"+ TV, but still feel like something is lacking. A Home Theatre system is always incomplete without a good surround sound setup. Though many people tend to give the sound system a low priority, it is one of the most important components in creating an immersive experience while watching movies or listening to music. Surround sound is now the new buzz in every household. Earlier, it was restricted to only those who could afford it as the systems were extremely pricy. But today, a person who can afford a TV can also go in for a surround sound system. But, without a proper understanding and setup, even the best of surround sound systems will sound like a stereo setup.
What is Surround Sound? Many people will know about it in terms of set up, but very few people will know it from technical point of view. Surround sound is not just supposed to be a multi channel sound setup, but it can also simulate a 3D sound field which can make a listener feels as if he is right in the middle of the scene.
Suppose if the movie scene is about a helicopter flying from top right area to bottom left, the sound effects are tuned according to the surround speakers. Considering this case and a four speaker setup, each angled at 90 degree and one of the speaker placed at 45 degree from the user. Now, the helicopter approaching sound will come from the top right speakers first and then the top left and the bottom left will start fading in the sound. This gives an effect of an approaching helicopter. Similarly, the sound will fade out in the bottom left direction. This gives an effect of the helicopter flying over the listener, and going in the bottom left direction.
The first kind of surround sound is stereo sound, with sound coming from two directions. But, a human's ear is able to distinguish not only sound from two direction, but from almost all directions. This gave birth to advanced kind of surround setup such as four speaker setup.
Now, almost all the movies and games are surround sound enabled, there is just no reason not to get a set of surround sound speakers. Today, we will guide you to set up a system of surround sound speakers. But, before that we will throw light on some concepts regarding different kind of speakers and sound standards.
Decibel (dB) is the unit denoted for sound loudness levels. There are two types of dB measurement. First, the dB is recorded by measuring audio signal-to-noise ratios; the difference between the quietest and loudest sounds is stated in dB. Second is the dB rating which varies according to the distance between the sound source and the listener.
It is that parameter which shows the amount of sound output measured at a certain standard distance with a standard amount of power supplied into the speaker. Efficiency rating standard is 1 watt at 1 meter and is measured in decibels (dB).
Human ear can hear sound frequency from 20 Hz to 20 kHz. It refers to what frequencies can be reproduced and how accurately they can be reproduced.
20 Hz - 40 Hz - Low Bass
40 Hz - 80 Hz - Mid Bass
80 Hz -160 Hz - Upper Bass
160 Hz - 320 Hz - Lower Midrange
320 Hz - 640 Hz - Midrange
640 Hz - 1.28 kHz - Upper Midrange
1.28 kHz - 2.56 kHz - Lower Treble (Highs)
2.56 kHz - 5.12 kHz - Mid Treble (Highs)
5.12 kHz - 10.2 kHz - Upper Treble (Highs)
10.2 kHz - 20.4 kHz - Top Octave
Impedance ratings are included to offer an idea of how much load the speakers can take are as far as connecting to the amp is concerned. There are two types of impedance.
The load supplied by the amp to the speaker. In audio system, the input impedance should be considerably larger than the output impedance to avoid signal losses and frequency-response irregularities.
The impedance of an electrical load attached to the output terminals of the speakers. Ideally, it is recommended that the output impedance of any audio amplifying equipment should be lower in comparison to what it is connected to.
Speakers constitute of a magnet. This magnet can also affect the near by environment and cause unwanted effects. Hence, magnetic shielding is very important. This feature is essential for the centre channel and front left/right speakers, when placed near the Television.