It is a phenomenon, that all of a sudden recording techniques are popular again that seamed to be dead (for good reasons). With the rise of 3D-Audio, 1st order Ambisonics recording techniques are in the game again and everything we learned about them in the last 40 years seems to be forgotten...
1. Press the MENU button in the top left corner
2. Choose a PRESET in the top dropdown menu or create your own setup using the settings below
by Helmut Wittek, 2016
Fig. 1 above: ORTF-3D arrangement, in a windscreen with the cover removed
Recording engineers who work with 3D sound face a difficult task when choosing a suitable recording technique. The number of channels is greater than with playback systems that operate only in the horizontal plane, so the complexity increases as well.
When a customer demands 3D audio rather than conventional 5.1 surround it may be tempting to apply solutions that are overly simple. But when a 3D recording has been made well, using a suitable recording technique, the advantages are impressively audible.
The "Image Assistant 2.1" is an interactive JAVA Applet that calculates the localization curves of arbitrary 2- and 3-channel stereo microphone configurations.
The brandnew app "SCHOEPS Image Assistant v3" is available as a browser version and in the Apple app store.
Image Assistant 
Ambience Recording 
ORF Surround Techniques 
ORTF-3D 
Microphone and Room 
AES-42 Digital microphones 
Helmut Wittek 
Günther Theile 