Since we only have two ears why multi channels audio?
Human ears hear 360 degree sound naturally since we born. Researchers spend years study how our ears listen to the sound. The stereo and mono audio are not nature if you put them in the perspective of nature sound.

To understand the evolution of speaker technology. We first need to know how artist working on a movie or music. The composition is a form of reconstruct layers of small sound clips. Either from virtual instruments or from recorded sound. The production process is the process of rearranging those elements. To recreate immersive experience for the audiences. For this reason to recreate the nature experience is the goal of most artists. However, single speaker has a lot limitations to simulate natural sound . So the multi speaker system was born. The idea is simple. Use speakers as sound sources to recreate realist soundscape. More speakers means more details and more realistic to mimic nature soundscape. Place them on the desired locations around listeners is the key to successfully.

How multi channels audio arranged?
It is not hard to find out the answer if you put your ear close and listen to your speakers. After few minutes you will start to notice. The center speaker is for dialogue only. Left and right speakers are used to send music, background sounds, sound effects and dialogues. Left rear and right rear surround speakers are used to send environment sound, background sound and sound effects. Over all you will hear sound mostly coming from the left and right speakers. For other formats like 7.1 or Atmos are use extra speakers for sending the extension of the sound information to improve its resolution. For example: ceiling speakers will be send environment sound and if there is a moving sound effects like helicopter flying pass....etc. It is all for the quality.

Why most sound are coming from Left and Right speakers?
Let us dive a little deeper to the cinema surround sound design. We know 5.1 means 3 speakers in front, 2 on the back and one sub Bass speaker. But why? To explain this we need to look back the history of the cinema sound design evolution throughout years. No matter how many speakers or audio channels the sound designer is using. There are only left and right stereo channels are used mostly. This is because a very good reason. That is the screen in the front of all listeners. The screen is only display certain coverage of the image. Most screen can only cover up to 120 degree of your eye's view angle. There is no need for the sound to be play outside of this area since there is no image. Also the film makers want you to focus on the front instead of to turn your head to look behind and missed whats main characters are doing. This is important as part of the cinema story telling. For the music the situation is even easier to understand. The lead signer is at the front with band members. There is nothing on the sides or behind.

Nowadays new concept of immersive object based surround sound is getting popular. This means to put you in the scenes use immersive sound. In another word, use 3D audio to let you feel that you are there in the scenes of the film or with the band in the live venue. However, only with headphones this is easy to achieve. If you would like immersive audio from YouTube to playback from your laptop speakers. You are having the same issue with the lacking audio channels to send audio signals.
Alternative Solution to Realistic audio !!
OPSIS II speaker is designed to provide an alternative solution to surround sound playback issues. OPSIS II's internal spatial decoding technology use two channels input audio to recreate 360 degree immersive nature realistic sound. This means you don't need to worry about audio codecs or hardware set ups. OPSIS II will recreate 360 degree realistic audio from all stereo audio inputs. The efficiency of recreated quality is depends only on the artist's original sound recording and production quality. For example: if more audio information and layers been put in for the final master soundtracks higher the realistic 360 sound details OPSIS II can playback.
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