From Wikipedia, the free encyclopedia
The ORTF stereo microphone system is a
microphone technique used to record
stereo sound. It was devised around
1960
at the Office de Radiodiffusion Télévision Française (ORTF)
at
Radio France.
ORTF combines both the volume difference provided as sound
arrives on- and off-axis at two cardioid microphones spread to a
110º angle, as well as the timing difference provided as sound
arrives at two the microphones spaced 17 cm apart.
The microphones should be as similar as possible, preferably
a frequency-matched pair of an identical type and model.
The result is a realistic stereo field that has reasonable
compatibility with mono playback. Since the cardioid polar
pattern rejects off-axis sound, less of the ambient room
characteristics are picked up. This means that the mics can be
set back further from the sound sources, resulting in a blend
that may be more appealing. Further, ORTF is easy to achieve, as
purpose-built microphone mounts are available.
As with all microphone arrangements the distance and angle
can be manually adjusted slightly by ear for the best sound,
which may vary depending on room acoustics, source
characteristics, and so on. But this arrangement is defined as
it is because it was the result of considerable research and
experimentation, and its results are predictable and repeatable.
These interchannel signals have nothing to do with interaural
signals, which come only from
artificial head recordings. Even The spacing of 17 cm has
nothing to do with interaural ear spacing. The recording angle
for this microphone system is ± 48° = 96°.
See also
-
Microphone
-
Jecklin Disk
-
NOS stereo technique
-
Stereophony
External links
-
WikiRecording's Guide to ORTF Stereo Technique Setup
Categories:
Microphones |
Recording |
Audio engineering
