Our team began the hi-fi prototyping stage by reviewing feedback on the lo-fi prototype. The feedback revealed confusion regarding the usage of both hardware (e.g. physical faders and mute switches) and touch-screen interfaces. We found it necessary to provide more clarity in our design. Also, our concept was difficult to present because a demonstration required a team member to stand directly in front of the prototype, partially blocking the audience’s view. We therefore sought to improve our craft of presentation.
The hi-fi prototype began with a lo-fi prototype, a generously donated Tascam M-3500 audio recording console, and an interesting collection of prototype ideas. The solutions we considered for presenting the hi-fi prototype were:
1. Build a styrofoam or wood frame model of an audio console and project the touch-screen interface on to it;
2. Gut the audio console, stand it upright, and project the touch-screen displays onto a vertical surface behind it. The operator would lay on his back underneath the console to demonstrate its operation;
3. Gut the audio console, stand it upright, and put a flat-screen television behind it so that its display becomes the touch-screen interface to the console; and
4. Use Chromakey to digitally replace the analog channel bank of the Tascam console with the touch-screen interface concept and project the output.
As we further refined our ideas, we realized that projection was central to the prototype. This led us to consider two projection methods: front-projection, in which the interface would be projected from above onto the surface of the audio console, and rear-projection, in which the interface would be projected from beneath the console onto its surface. The prototype featured a combination of touch-screen and hardware controls, which would require a custom physical overlay to replace the console’s existing analog electronics. After taking this into consideration, we opted for a front-projection rig comprising three pieces of presentation hardware: a projector to display the touch-screen onto the surface of the audio console, a camcorder to capture the entire audio console and the operator’s movements, and a second projector to display the camcorder feed for the audience.
Creating the Physical Framework
The next step was to dissemble the Tascam to remove the analog electronics between the channel faders and the meter bridge. Following this, we moved to the custom overlay that would replace the electronics. We initially experimented with MDF wood as the new console surface, which would have been an ideal material, however, we were not able to acquire a thin enough (1/4″) sheet. We substituted plywood, and opted for a panel of frosted acrylic to simulate the touch screen.
We continued to assemble the console surface; while some group members drilled holes for the 24-knob bank and hard mute buttons, others worked on the paper fader overlays and acrylic sheet preparation. Hardware salvaged from the original console surface would be reused for the knob bank and hard mute buttons.
Simulating a Touchscreen Interface
When the console surface was nearly complete, we acquired a projector for the touch-screen surface. A HD camcorder was then affixed to the projector, attached to the lighting grid of the design lab where construction took place, and positioned directly over the audio console. To our dismay, we discovered that projecting onto the acrylic surface resulted in a blurry image due to the material’s light diffusion properties. We solved this by covering the console surface with black paper, and with the addition of the Go/Back and Blind/Live switches and Numpad buttons, the console surface was complete.
We then moved to production of the core artwork for the console: the channel strips, effect buttons, cue timeline and cue list. This helped to tune the output resolution of the computer that would be connected to the projector, and with placement of the touch-screen components relative to the physical console surface. We then drafted a user scenario for the live presentation and user testing. From the user scenario, we developed a list of screens that we would need to display to fully demonstrate the interaction flow. The completed artwork was consolidated into a Keynote presentation to form the step-by-step interaction flow, which would be projected onto the console surface.
In summary, the Sound Experience team designed a hi-fi prototype capable of being used in user testing and presentation. Using presentation software and a human monitor, we was capable of simulating core functionality of our console prototype in an arbitrary and scenario-guided operational sequence.