The bug eye rig has sprouted a few more antennae. First some back story-
I've been playing around with some surround sound recording ideas since last spring. My approach is to not compromise my standard two channel stereo recordings by changing the stereo mic array, but to add two optional, additional mics recorded as center and back channels. I've been doing this for a while now for low-profile recording using baffled omnis and the results have been highly encouraging- adding another dimension of reality to what I had previously considered very good stereo recordings that already convey the illusion of 'being there'. It has been so encouraging that I decided to try and apply the technique to a standing, open rig, somehow without the baffles that would block sight lines.
I'd already been running two simultaneous stereo rigs for some outdoor festivals which is great for comparing techniques and equipment and have sometimes toyed with surround playback. I'd usually run my 'big rig' with ADK TLs or Pleuso P-Stereo mic in say Blumlein a few feet in front of the little spaced omni bug eye rig pictured here previously. The two micstand formation formed a sort of triangular Deca tree shape. Setting up the two separate stereo rigs that way allowed me compare the two stereo recordings on their own, or to try sending the blumlein pair to the front L/R speakers and the omni pair to the surround speakers. I also played with summing the blumlein pair to form a single forward facing fig-8 (M/S technique) and using that as a center channel along with the L/R omnis for L/C/R playback. All good fun but none of those surround experiments really added that much over the stereo recordings, certainly nothing like the baffled surround recordings I've been making.
I figured that the baffle was an essential element to provide enough directionality and isolation of sound between front and back channels with the meter or so spacing between mics that I was using for practical reasons. Eliminating the baffles I needed something to provide directionality to the highly omnidirectional miniature 4060s. I considered using clear plastic CD jewel case covers or the clear 'CD's that cap the stack on CDR spindles like mini-baffles and boundary mounting the mics to them, one at the end of each telescopic antennae, but the more I thought about it the more that seemed a bad idea. I instead decided to return to using the APE-like Nerf foam balls I've pictured here previously which provide some top end directionality, seem in keeping with the obvious Decca tree using classic Neumann M-50s influence or the modern DPA surround tree using omnis with APE attachments. They are also much more practical to use and to keep less visible.
I've used the rich sounding and costing
DPA surround tree and APE attachments as design inspiration and developed the 'poor man's' version that you see below. Other big influences that have shaped or confirmed my thinking on this are
Michael Williams' Magic Arrays for simultaneous recording of 1,2,3,4,5 or more channel sound, each of which stands on it's own, with a single array and his previous MMAD data for 4-channel quad arrays using omnis and subcardioids.
I'll just address the non-low profile open recording here and the modification of the bug eye rig I've posted about previously. The signal path is (4060s > CA-Ugly > R-09) x2. One rig records the L/R pair and the other the C/B pair. For playback I currently hook up both recorders' outputs to the 6-channel DVD input of my stereo amp (splitting the back signal to both surround speakers) and play both recordings simultaneously. It takes a few quick jabs of pause/play to match up a percussive impulse and sync both machines, but they do not seem to drift audibly over the course of a 90 minute recording. Unlike matrixing a 4 channel recording the signals are not summed and are somewhat less susceptible to comb filtering problems if slightly off sync. I have not found the time to play around with the recordings on the computer in post yet, but plan to eventually look into syncing the two stereo recordings (L/R & C/B) and encoding to 24/48 DTS surround. I mostly play everything off the computer into the home stereo these days but I could also burn DTS encoded surround CDs or DVDs. I also plan on trying various methods of decorrelating the mono back channel feeding the two rear surround speakers. Any ideas on ways of doing that are very welcome. I need a four channel output sound card for my editing machine before I can do any of that.
First a photo of the previous dual rig setup. This was from a month ago, Peluso P-Stereo up front, antenna spaced 4060s one row directly behind. Here the 4060s are not mounted in the foam Nerf balls and so are 'fully omni'. Both sound very nice as stereo recordings but there is not enough distance between rigs or imparted directionality to make the 4060s useful as surround feeds. (five rigs can be seen, the Peluso is in front, the antenna spaced 4060s are directly behind another rig)-