1. A Solid-State Ion Tweeter
Our Team Members
Rob Alejnikov
Mark Blattner
Colin Joye
Our Advisors
Dr. Robert Caverly
Dr. Pritpal Singh
Dr. Joseph Kozikowski

2. Presentation Objectives
Need Identification
Project Objectives and Analysis
Possible Solutions
Strategy

3. Need Identification Increase the Range of Optimal Listening Area
Quest for higher Quality Sound Reproduction

4. Off-Axis Frequency Response
Conventional Speakers
Frequency Response
degrades as Off-Axis angle increases
Must be On-Axis for Optimal Frequency Response
Constructive and Destructive Interference causes unpredictable Frequency Attenuations

5. Project Objectives
Create a Device that Offers the Same Frequency Content in all Directions
Concentrate on High Frequencies Since They Tend to Beam the Most

6. Possible Solutions Line Source Omni-Polar Siamese Tractrix
Emits a Line Dispersion Pattern
Omni-Polar Siamese Tractrix
Produces Radial Dispersion Patterns
Hypersonic Pseudo-Point Source
Offers Hemispherical Dispersion Patterns
Omni-Directional Point Source
Radiates Spherical Dispersion Patterns

7. Types of Sources Line Source Omni-Polar (Siamese Tractrix)
Solves Vertical Positioning
Does not solve Horizontal
Omni-Polar (Siamese Tractrix)
Solves Horizontal Positioning
Does not solve Vertical

8. Types of Sources (cont.)
Hemispherical Source
Solves Horizontal and Vertical Positioning
Uses Beat Frequencies
Requires specific physical positioning
Point Source
Solves both Horizontal and Vertical Positioning

9. The Point Source Decision
The Point Source Offers Nearly Ideal Spherical Dispersion Patterns
Corona Discharge Creates a Nearly Ideal Point Source
Use of Corona
Allows for a More
Perfect Transient
Response

10. Point Source Implementation
Ion Flame
Best Practical Point Source
Existing Ion Tweeters use Vacuum Tubes, creating Excessive Heat
Higher Efficiency could lead to wider Frequency Response
Goal
Raise Efficiency, then widen Frequency Response

11. Strategy Model Corona Discharge as an RLC Circuit
Model Existing Ion Tweeters with above model
Design and Build Efficient, High-Voltage Circuit
Control High-Voltage Circuit With Audio Signal
Time Permitting, Upsize High-Voltage Circuit
Time Permitting, Design/Build Power Supply

12. Semester Plan

13. Join Us… At http://ee.vill.edu/ion to Monitor Our Progress References
Olson,Harry F. Modern Sound Reproduction. Van Nostrand Reinhold company, New York, Pg30
Web References are Located on Our Web Page
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