Meridian Audio 565 - Manual (Page 43)

DSP presets
39
Ambisonic
The Ambisonic DSP preset is designed for replaying material
encoded in UHJ format, the two-channel stereo-compatible
encoding found on Ambisonically-recorded discs and
broadcasts. This material is specifically encoded for surround
reproduction and can give breathtakingly realistic sound when
replayed using the digital surround processor.
Ambisonic surround sound is quite unlike conventional stereo. A
special microphone technique picks up the sound of the original
performance in all three dimensions, allowing an archive to be
made which describes the sound field exactly at that position.
The microphone signals are then encoded using a phase-
amplitude matrix to allow the effect to be conveyed on two-
channel carriers (like FM radio, LP, or CD).
The digital surround processor uses accurately matched,
frequency-dependent, phase-amplitude matrices to decode the
signal and construct the signals for each speaker feed.
The fundamental difference between Ambisonic surround sound
and conventional stereo is that the signals from all the speakers
combine to produce a coherent sound field at the listening
position, giving the illusion that you are sitting inside the
recording space whether you are at the exact central seat or well
off to one side.
Of all the signal-processing options, Ambisonic is the one that
requires the greatest attention to speaker choice and
positioning.
Super Stereo
Super Stereo synthesises a signal from a conventional stereo
recording or broadcast so that it can be decoded using the
Ambisonic decoder. The result is especially effective for two
particular types of recordings:
❍ Those using true coincident microphone techniques.
❍ Multi-tracked or multi-miked recordings.