I’ve been thinking a little about the next iteration of my surround recording rig today, and have been pondering trying a few different things out with regards to microphone angles and spacing. There is an interesting web based app that you can use to visualise the effects of changing microphone polar response, angle or distance for a stereo pair of microphones. Check it out at:
http://www.sengpielaudio.com/Visualization-AB60-E.htm
Also on the website is a document that includes a neat diagram of the John Klepko developed “5-Channel Microphone Array with Binaural Head for Multichannel Reproduction”. I am thinking of toying around with the front configuration of this array along with an OCT alternative. Then couple these options with an ORTF Rear. I have never used an OCT set-up, but my concern is about versatility in that the LR pair don’t seem like they would be useful on their own as a standard 2.0 stereo pair, whereas the LR pair in Klepko’s array would be.