Below are a number of different approaches using standard microphones for surround recording of music, all of which use space between the microphones, which I consider superior for surround recording and playback of music than a coincident setup.
All of these are main-channel multi-microphone arrays using normal microphones, akin to using a stereo-pair for recording two-channel, in contrast to building a stereo or surround mix from individual panned spot or close microphones:
• Williams MMAD (Multi-Microphone Array Design: extension of the 2-channel Stereo Zoom approach to 3/4/5/6/7 channels, using identical microphones of various polar patterns, optimized for psychoacoustically correct imaging across each segment around the array, and linking between all segments)
• OCT + surround mics (Optimum Cardioid Triangle: optimized for channel separation across the front three channels, one forward facing cardioid + two sideways facing spaced supercardioids for L/C/R, + surround channel mics)
• 5 mics evenly spaced in a row (David Greisinger's technique. 3 spaced across the center as L/C/R, 2 flanking as surround channels, using omnis or forward-facing directionals as appropriate. Works nicely across a stage-lip)
• Decca Tree + surround mics (3 spaced omnis in a traditional triangular Decca-tree formation + surround channel mics)
• Fukada-Tree (basically a variant of Decca tree with the center mic less forward + outriggers)
• INA-5 (a star-like semi-near-spaced arrangement of 5 cardioids with the L/R pair facing to the sides)
There are other techniques I've not listed which are not as suitable for music, which include some common ones that are more appropriate for recording location ambiances for television, film and radio production work. Although not as suitable for the main (L/C/R) channel pickup for music recording, those techniques could be used for ambient sound pickup for the surround channels. There are also a number of techniques for arranging additional ambiance microphones behind the main microphones, which are sometimes combined with the techniques listed above, but I they complicate these basic setups for incremental gain and I haven't felt them necessary, practical or worth the additional hassle.
I’ve used the first four listed above. The Williams MMAD is perhaps my favorite when arranged properly but takes a more fiddling and space to setup. It has worked great on-stage in a good room. I can run variants of OCT from a single stand and that has worked really well for outdoor recording FOB. It’s mostly what I do currently. The Gresinger technique is easy to arrange and setup across the front stage-lip since the microphones are all in a line, and sounds big and spaced omni-like with good coverage and imaging up close. That's is the way I run the ~2m wide-spaced omnis as surround channels in my outdoor OCT setups to keep everything manageable on a single stand. Decca tree + surround takes as much or more floor space than MMAD setups (it’s more or less a loose MMAD setup using omnis) but is also very forgiving without worrying too much about setup specifics. It’s basically another improved version of a spaced omni pair.
In contrast to these techniques, most all the microphones listed in this thread are coincident-capsule designs, with a few exceptions. The near-spaced exceptions are the various Holophones (near-spaced baffled-omni designs) which IMO appear convenient to use but do not measure or perform very well for music recording, confirmed by samples I’ve heard; the DPA 5100 (coincident directional L/C/R microphones + baffled omnis); and the Schoeps ORTF Surround setup (limited to 4-channel output, but uses their excellent capsules and expands ORTF to quad).
I’ll list a few other esoteric surround microphones in a following post since that’s the focus of the thread, but first I wanted to mention these spaced setups using traditional microphones which are usually much better for actual surround recording and playback of music than any coincident technique, at least over more than 4 playback channels.
Topic: [List] Surround Sound Microphones (Read 7513 times)