“An Ambisonic Microphone records audio in multiple directions allowing you to change the direction of where you are listening after recording, sometimes while you are listening. There are several of these on the market but we are going to build our own. Construction uses a 3D printed housing, very good mic capsules and deceptively simple electronics. You can choose two mounting methods, one will mount on a traditional mic strand using a mic clip. The second integrates a -20 bolt into the housing allowing you to use alternative mountings such as GoPro mounts and Cold Shoe camera mounts. Both have a great eco system of options. You could use a -20 nut as well, but I do not recommend it. The electronics, which use 48V phantom power are just two components, both of which will fit into the XLR connector shells. Don’t let the simplicity fool you: This mic is better than some that cost a lot more. It has low self noise and sounds great. I have used it for very quiet ambience recording, a choir and loud traffic noise. Listen to them all in the final video at the end.
The original concept was developed in the 1970’s in the UK. The first one was the Sound Field microphone. It was invented by Michael Gerzon and Peter Craven and used a tetrahedral array. This generates what is referred to as “A” format. That means it is raw four channels of audio that needs to be further processed when mixed down. The other format used is “B” format which for first order ambisonics, is encoded into XYZ and W. W is the equivalent of an omni microphone signal. X,Y and Z are figure 8 pattern responses facing, front/back, left/right, and up/down. The tricky part is sorting all of this out when you bring it into your DAW. There are two standards for B format and the only difference is in the ordering of the channels. I am using Reaper and this instructable includes templates and links to all the plugins required. Way more in the “How to use this thing” section.”