The SoundField SPS422B
Issue 1.7
User Guide
Page 14
SOUNDFIELD B-FORMAT:
B-FORMAT - HOW DOES IT WORK?
The SoundField Four Capsule Array
The four outputs from the capsules of SoundField microphones (called the A-Format signals) are
converted by the MKV, ST250 and SPS422B processors into four components known as
SoundField B-Format. These convey all of the information of the entire soundfield, and are the
three directional vectors - fore/aft, left/right, up/down - and absolute pressure.
The capsules are placed tightly together to
eliminate the phase problems associated
with ‘spaced’ multi-microphone set-ups.
From a single point source sound is
received from all directions, reproducing a
realistic listening experience.
The signals from the four capsules are fed to the micro-
phone’s control unit where it is converted into four channels
of SoundField B-Format, known as W, X, Y and Z.
Mono, Stereo, Mid-Side, 5.1 and all future surround
formats can be derived from this information.
B-Format Illustration
B-Format is three dimensional acoustical information and
consists of three figure of eight polar patterns called X, Y
and Z plus one omni called W.
X gives Front to Rear depth information, Y gives Left to
Right horizontal information and Z gives vertical height
information. From the omni W sub-bass (LFE) is extracted.
SoundField are the only microphones in the world that
generate B-Format.
