Daniel Valente
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Twitter Account
I just got started on Twitter and I have to say, it’s a great tool for sharing quick information with people and even getting in lively conversations. That being said, all is going well with my thesis. I am currently getting ready to present a draft of my defense at the Ph.D. seminar this Friday. This will also serve as a good practice for my talk at the ASA meeting in Portland on May 18th. I am currently working on revising my JASA article, and my thesis as well as various other projects.
Wave-Field Measurements
This is a wave-field spatial sampling of the array used in my research. The prime advantage of a WFS presentation system is its ability to maintain a coherent wave front to a large area or “sweet-spot”. You can easy see why this is advantageous compared to a standard stereo or amplitude-panned surround array. The ideal listening position for these (Stereo, 5.1) systems is quite small (a narrow line equidistant between two loudspeakers in a stereo configuration or a single point in a surround-sound configuration). Move your head outside the “sweet-spot” and you will no longer be able to judge the locational sonic cues that the presentation system is providing. This measurement was made by taking an impulse response through the WFS system using an array of microphones. 7 microphones were used, spaced 10 cm apart, and 28 positions were taken making a matrix 1.4 m by 1.4 m in dimensions with a spatial resolution of 10 cm. This matrix was then filtered with a narrow-band band-pass filter in order to make the “sonic snapshot” shown above. The picture above represents a 250 Hz sound wave being created by a virtual omni-directional sound source located 1 m from the linear WFS array. Given the spacing of the loudspeakers (17cm), the array is capable of providing a coherent wave front up to 600 Hz due to spatial aliasing. The WFS system maintains the wave-curvature as well as coherence and preserves distance cues which include sound pressure and high-frequency attenuation due to thermal relaxation.
Digital Compositing for Subjective Perceptual Testing of Room Acoustic Parameters
I have posted a video of the technique utilized for the digital compositing of musical performances in an audio-visual environment. This technique was used for my J. Acustica Paper: Subjective expectations adjustments of spatial acoustic parameters to match visual environmental cues, with varying source stimuli. This technique allows me to record a musical performance against a monochromatic background in a sound-treated studio (to minimize room reflections), and position him or her into any virtual or real environment for the perceptual judgement of acoustic parameters.
Curtis Bahn and Dan Valente
Two papers in the works
Speakers.
The WFS system is in place in the live room of Lab B. 32 channels of loudspeakers will reproduce spatially accurate audio to 1.1 kHz. This will be coupled with a 5-channel surround sound system to provide late reverberation. Calibration and testing will begin next week. To facilitate driving each channel simultaneously, two additional analog daughter-cards will be installed in the G5’s HDSP 9652 by RME. This will allow for 40 discrete channel outputs.
Wave Field Synthesis 32-channel Loudspeaker Array
The new Wave Field Synthesis (WFS) loudspeaker array will be installed in the Gurley Lab this week. This hybrid virtualization system will provide from a highly spatial accurate (wavefront synthesis up to 1.1 kHz) frontal array coupled to a 2D HD video projection system. Room modeling will be accomplished in real-time using a custom convolver coupled to a surround speaker array. The WFS system will spatialize up to 16 virtual sources in a modeled room with up to second-order reflections. This reproduction system is similar to that used in my Master’s research, but with half the spacing between speakers in the frontal array (9.5 cm). The WFS system will be used for real-time telematic musical performances, research on audio-visual interactions and multi-modal distance perception.
Performance at RPI for NY Times
