lately I've been tickled by the idea of going ambisonics, both recording and creating 3d sound ambients, anyone have any experience? DIY mikes?
This app sounds good, it can use your phone's accelerometers to track your head and play ambisonics recordings.
I usually record with my Zoom H4n, absolutely love it, great built-in mikes, and very versatile combo jacks with high impedance matching, the preamps can be better, you can always use an external pre if you need more detail.
I also love to hook up a couple of electret capsules, usually very distant from each other, approx. 5mt, to get a nice wide effect.