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	Ambiophonics Ambiophonics and the 360 degree version, Panambiophonics, may be regarded as the only sound recording and playback system that is capable of accurately reproducing sound images based on correct psycho-acoustic principles. A typical recording head and playback system is as shown. So what is wrong with traditional recordings ? The ear relies on several mechanisms for detecting the location of sounds, briefly summarized as follows: 1. The relative sound pressure level between the left and right ears. This is the obvious mechanism used by traditional stereo. A large signal from the left channel gives the impression of an image from the left. This mechanism also involves the presence of the listeners head which affects the relative sound levels at each ear. 2. The time delay of sound reaching each ear. This produces complex frequency dependent responses used by the ear to locate sources. This again involves the shape of the listeners head which produces diffraction effects and physical separation of the ears. 3. The pinna (outer fleshy part of the ear) produces yet more complex effects which are used to locate sounds. We can all locate sounds with just one ear and this response is due to an amazing mechanism involving the pinna. 4. Only 60 degree coverage For realistic reproduction we need much wider coverage to give the potential for better realism. Traditional recordings (2 channels, playback loudspeakers placed 60 degrees apart) fail on by largely ignoring the above points. Microphones are invariably used in close proximity to instruments and no original and natural sound location cues are recorded. Sound images have to be synthesised usually by altering the relative level of sound to left or right channels.	Marshall Choong listening room with experimental dividers Mk 4 Experimental 6 channel Panambiophonic Recording Head 2007-05-20
	Stereo Crosstalk Another unnatural playback effect is the crosstalk of signal from one ear to the other, adding to the signal reaching the head from the the opposite channel. Panambiophonic Recording and Playback Recording normally uses a dummy head as shown above with multiple microphones in front and behind the head. Playback uses a loudspeaker arrangement called a 'stereo dipole' which requires the 2 channels to be placed side by side in front of the listener and an acoustic divider separating the sound from each speaker. This arrangement removes most of the stereo crosstalk mentioned above.
	General Performance of this system 1. Excellent front stage performance (equivalent to left and right stereo) with improved height and depth information. 2. Improved width accuracy but still only extending to 45 degrees from centre. An unstable region is encountered before far left and far right speakers can take over. 3. The physical divider is unlikely to be accepted in a domestic environment.