For use in multi-channel capable VST hosts such as Nuendo 1.5 (and above), AudioMulch, Bidule etc.
B-Mic is a 64-bit double precision ambisonics processor optimised for sound quality . In Nuendo, it should be used in the master effects section, positioned prior to the decoder, if this is in use.
Make sure your B-format signal is in W, X, Y, Z (1,2,3,4) format. Currently (as of July 2002) Nuendo and most other VST hosts do not offer a multichannel file input option so any B Format recordings have to be provided as two stereo files feeding separate input channels. Configure Nuendo so that these two channels feed the processor on these busses. BPan connects itself correctly automatically.
B-Mic allows you to generate a virtual coincident stereo pair of microphones from a B-Format soundfield, either recorded or synthesized. It has three controls;
- a pair of direction controls, Azimuth and Elevation, which allow you to set the direction in which the pair points (Azimuth in degrees anticlockwise from due front, elevation in degree from horizontal ( 90 degrees is straight up))
- an angle control which sets the angle between the microphones
- a pattern control. This varies the directional patterns of the virtual microphones from cadioid at the centre point, to figure of eight when at +1 and omnidirectional when fully towards the opposite direction at 0.
Decoding using B-Mic
The plugin can also be used as the basis of a fully programmable decoder matrix. You can do this by using multiple copies of the plugin, each generating the feeds for two (usually diametrically opposed) speakers. This is normally accomplished by building up a patch in a software package such as Audiomulch, which contains one copy of the plugin for each pair of speakers, all fed with the same B format signal, angle controls set at 180, but with their azimuth/elevation adjusted so that the mic pair 'pointing' direction is perpendicular to the axis of the speaker pair. By modifying the polar diagrams, different varieties of decode can be set up, either overall, if you set them all to be the same, or on a per-pair basis. If you discard one output - thus using one plugin per speaker - and set the inter-mic angle to zero, you get even more control. Don't forget, though, that if the angle is set to zero the 'pointing' direction of the pair and the direction of the speaker become the same. It is also possible to cascade the B-Mic plugins with delay and gain modules to enable decoding to even more irregular arrays.
Simply drop the ambMicedit.dll file into any plugin folder currently active in Nuendo or other VST software that you use, but I am now recommending that you put all the Ambisonics plugins in a new folder called 'ambisonic' inside your main VST plugins folder.
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Last updated on Thursday February 27th, 2003