Matching Items (2)
Filtering by

Clear all filters

156401-Thumbnail Image.png
Description
Despite the growth of technology in music composition and performance, professional clarinetists maintain that air microphones are superior to piezoelectric pickups. Pickups offer increased mobility, isolation, and reduced feedback, but air microphones are used simply for the perceived sound quality. In this study a ported barrel pickup and a contact

Despite the growth of technology in music composition and performance, professional clarinetists maintain that air microphones are superior to piezoelectric pickups. Pickups offer increased mobility, isolation, and reduced feedback, but air microphones are used simply for the perceived sound quality. In this study a ported barrel pickup and a contact transducer pickup placed at various intervals on the clarinet were sampled and compared to a reference recording to determine how the sound differed for each method. In addition, the history of wind instrument pickups, the acoustics of the clarinet, and the basics of piezoelectricity were discussed to help examine the results. The pickups were examined in three ways: overall level in decibels, frequency cutoff, and overtone displacement. Through these results it was determined that the most accurate methods of clarinet pickup are the ported barrel pickup, contact transducers closer to the vibration of the reed such as the ligature or barrel surface, or a transducer placed at the end of the bell. These findings were consistent with the discussions regarding history, clarinet acoustics, and piezoelectricity. This study also produced a reference for the sounds associated with different pickup methods, as well as possible improvements for clarinet pickup design.
ContributorsEnglert, Patrick William (Author) / Spring, Robert S (Thesis advisor) / Gardner, Joshua T (Thesis advisor) / Caslor, Jason (Committee member) / Rogers, Rodney (Committee member) / Arizona State University (Publisher)
Created2018
154094-Thumbnail Image.png
Description
In this thesis, a digital input class D audio amplifier system which has the ability

to reject the power supply noise and nonlinearly of the output stage is presented. The main digital class D feed-forward path is using the fully-digital sigma-delta PWM open loop topology. Feedback loop is used to suppress

In this thesis, a digital input class D audio amplifier system which has the ability

to reject the power supply noise and nonlinearly of the output stage is presented. The main digital class D feed-forward path is using the fully-digital sigma-delta PWM open loop topology. Feedback loop is used to suppress the power supply noise and harmonic distortions. The design is using global foundry 0.18um technology.

Based on simulation, the power supply rejection at 200Hz is about -49dB with

81dB dynamic range and -70dB THD+N. The full scale output power can reach as high as 27mW and still keep minimum -68dB THD+N. The system efficiency at full scale is about 82%.
ContributorsBai, Jing (Author) / Bakkaloglu, Bertan (Thesis advisor) / Arizona State University (Publisher)
Created2015