2012-11-29

Roll, Align, Draw, Record


 "Rolling ruler used by the architect Cedric Price"; Image courtesy of Geoff Manaugh & CCA

A few years ago, Geoff Manaugh of BLDG BLOG shared this photo while he was blogging from the archives of the Canadian Centre for Architecture. It is a rolling ruler used by the late British architect Cedric Price. This pocket tool undoubtedly aided the architect in his sketches, speculations, and visionary projects. Whipping the ruler around, movements of a pencil-poised hand could quickly turn a blank page into a tiny world of ideas, drafted, aligned, exact yet also invitingly inexact.

The pocket rolling ruler is a vestige not only of the drafting days but also the days when architectural visions were best crafted in a sketchbook. Plenty of architects still sketch, but, needless to say, the laptop is the portable tool of choice. And what amazing tools we have there! I feel no nostalgia for hand drafting tools and in a way architects are becoming more crafty by "making" their own tools i.e. designing scripts, simulations, and so on.  Still, there is something to be said of the simplicity of Price's rolling ruler. An architect may have a studio full of tools to render and represent a building, but all the tools needed to craft an idea should fit in a pocket.

Fun Palace by Cedric Price
Price was a paper architect. The ruler assisted Price in drawing lines on a page to represent his ideas. A sound architect is equally engaged in the world of ideas, as opposed to built things. Moving beyond the page, however, the sound architect cannot shape ideas without also shaping sound. A simple analog to Price's ruler is the microphone. It is portable; it has its own metrics (i.e. gain, directionality, frequency response); it can be tracked along an x, y, or z axis just as the rolling ruler slides along (though only in a single axis).

The microphone is good at recording voice, music, or, in my experience with field recording, an ambient scene. I have used microphones in stereo/binaural combinations which allow for a more spatial recording than a single microphone. Yet, the problem is essentially one of representation versus simulation. Both the rolling ruler and the microphone are concerned with representation. The ruler says: "How can I make a legible image that stands in for something else?" The microphone is a painterly tool as the holder of microphone decides what to record, how close, etc. The end result is an audio image, played back on a pair of speakers or headphones, which merely represents the space recorded by the microphone. Little of the "space" is being simulated there. A stereo recording is largely a flat canvas.

Shaping sound, shaping architecture, should be anything but flat. Architecture and sound decay; architecture moves in time; sound reverberates. Why have we (architects) not brought to the complex task of constructing things in four dimensions a tool which is adequate to capture those dimensions? More than capture, more than represent, a tool adequate to simulate four dimensions?

Enter the Ambisonic microphone.

I first mentioned Ambisonics here on Soundscrapers two years ago, while taking part in a CCRMAGray Area Foundation for the Arts workshop on spatial sound. Ambisonics is a sound format which permits a full three-dimensional representation of sound--Up, Down, Left, Right, Front, Back, and all directions in between, known as periphonic recording. A good setup, with enough speakers, does the amazing thing of making the speakers disappear. Sound does come out of the speakers, but you don't hear the individual speakers; what you hear is a field of sound, seemingly without a locatable source. At least the artificial source is camouflaged by the mirage of real sounds in space.

To demonstrate Ambisonics during the workshop, the organizers took a pair of keys and jangled them at close proximity around an Ambisonic microphone that was in the other room. While I was sitting in the sweet spot of the speaker array, I felt as though a colossal pair of keys were being shaken all around my head. The idea that the speakers were playing sound disappeared, and I was left with the unforgettable, impossible sensation of a pair of keys larger than the room itself, somehow moving around my head.  That was architecture.

Recently I looked into what it would take to get into Ambisonics, beginning with a microphone. I was thrilled to learn I could build my own Ambisonic microphone! This task would require assembling four microphone capsules into a perfect tetrahedral frame, while making over a hundred soldered joints, any number of which not done right could short out the microphones.  Having only soldered a few times in my life, and despite knowing that so many things could go wrong with the construction of this tool, I felt it necessary to craft the microphone myself. Traditional Japanese carpenters, after all, must shape their own tools, if only for the practical reason that a tool with heavy use will require constant tuning and repair. But for a more spiritual reason too: the tool is to become a part of its maker. I wanted to do more than own a tool. I wanted the tool, the microphone, to be a part of the way I experience the world and consequently give shape to it.

The process began with the construction of a tetrahedral, made from copper wire. Hours turned into days. Measuring, snipping, torching, filing, grinding, cursing, soldering, sighing, sanding. The frame was done. Over the following days, I set in the microphone capsules and wired them up.

Construction of an amibsonic microphone. More photos here.
Next the enclosure, a black box. (I felt it was inevitable that when I finished the microphone would not work, and I would be left with this mute, black box...). I dropped in at a hackerspace, Ace Monster Toys, to use their drill press.

The Black Box.
I soldered dozens of resistors, diodes and capacitors to the circuit boards. Wires with their frayed ends, one by one, found a home. The circuit boards (which amplify the microphone signals) slid into the case. I dropped two 9V batteries in, screwed the frame closed, and flipped the switch.

Tool of Choice: The Finished Ambisonic Microphone.
A tiny light came on. I registered audio signals on each of the four microphone inputs. The microphone is live. And there is a new tool in my pocket.