EBS stereo system
The EBS stereo system describes a special type of equivalence stereophony . It is named after the well-known German sound engineer Eb erhard S engpiel , who developed this type of stereo microphone together with a group of sound students. Since the "invisible" recording area is identical to the "visible" opening angle in this special stereophony , the EBS stereo system is particularly suitable for inexperienced sound engineers.
history
With his students from the Tonmeisterinstitut of the Berlin University of the Arts , Eberhard Sengpiel researched a stereo microphone system that should offer an even distribution of the phantom sound sources on the loudspeaker base . As a result, he developed the EBS system, in which the directional mapping is made up as equal parts as possible of time and level differences.
Lineup
The EBS system was developed for two small diaphragm microphones with cardioid characteristics. These are described with a microphone base of 25 cm and an outward offset angle of ± 45 °, which corresponds to an opening angle of 90 ° (α = 90 °). The recording range is also ± 45 ° = 90 °.
particularities
Recording area = opening angle
When placing a microphone system , the effective recording area is essential for the subsequent stereo image . This results from a complicated calculation from the microphone base ( distance of the microphone capsules), directional characteristics of the microphones and opening angle (also axis angle). If the microphone system is not placed in such a way that the recording angle fits the sound event to be recorded, the lateral phantom sound sources can either be overemphasized and thus the so-called "center hole" or the stereo base width is not used, which in turn leads to a narrow sound image.
The EBS system is similar to the ORTF stereo system . However, it has the special feature that the recording area is 90 ° and is therefore identical to the opening angle. This has the advantage that the receiving area can be placed more easily. This is normally not visible and can only be estimated when placing it. The opening angle of the same size in the EBS system, on the other hand, can be used as a visual guide.
Balanced mixed stereophony
Äquivalenzstereofonie systems (also called mixed stereophony), such as ORTF , NOS or DIN, are a mixture of Inter Channel - intensity stereophony (also Pegelstereofonie ) and Interchannel- Laufzeitstereofonie .
As a rule, they form directional mapping either mainly through time differences (e.g. NOS stereo system: 57.7% through time differences , 42.3% through level differences) or predominantly through level differences (e.g. ORTF stereo system: 60.6% due to level differences, 39.4% due to transit time differences). The EBS system, on the other hand, provides a very balanced directional mapping of 53.2% from transit time differences and 46.8% from level differences.
See also
- List of audio terms
- Localization (acoustics)
- binaural
- Audio event direction
- Equivalence (sound engineering)