1. Phased Speaker Array : Phase of Our Lives
Dave Simley and Rosemary Montgomery
Group #68
ECE Senior Design

2. Table of Contents Objective Introduction Design Physical Design
Conclusion

3. Objective
Music can really brighten the mood, but interference patterns greatly affect the quality of the sound.
Our design is a phased speaker array that can reduce these interference patterns
When the music is phase corrected, the listener would hear their music at a considerably louder volume and with a richer tone
Add graphs from
-Better explain steering
-talk about range of product (podcasts, audiobooks, etc.. Or educational)
-”set the scene”

4. A Phased Speaker Array…
Detects the location of a person in a room
“Steers” the sound towards the listener by
Calculating the appropriate time delay and
Sending delayed signals to the speakers
-Better explain steering
-talk about range of product (podcasts, audiobooks, etc.. Or educational)
-”set the scene”

5. Block Diagram

6. Design: Modules
Signal Input: ADCs convert the input analog signal into digital values
IR Receiver: Detects IR source in the room and sends the location to the microcontroller via I2C
Control:
Microcontroller processes the information and outputs delayed signals.
The DACs then convert the digital values back to analog signal.
Speaker Array: Amplifies the signal and sends it through four speakers

7. Design: Signal Input Module
An analog-to-digital converter (ADC) constantly samples an analog input
Interfaces with MCU
sends over digital value of
input signal
Analog Input
(-5 to +5V)
Digital Output
(0x000 to 0xFFF)
Source: [5]

8. Design: Modules
Signal Input: ADCs convert the input analog signal into digital values
IR Receiver: Detects IR source in the room and sends the location to the microcontroller via I2C
Control:
Microcontroller processes the information and outputs delayed signals.
The DACs then convert the digital values back to analog signal.
Speaker Array: Amplifies the signal and sends it through four speakers

9. Design: IR Receiver Module
Interface: I2C
Detecting distance: 0~3m
FOV: 33 degrees
Potentiometer alternative for manual operation
Source: [1]

10. Design: Modules
Signal Input: ADCs convert the input analog signal into digital values
IR Receiver: Detects IR source in the room and sends the location to the microcontroller via I2C
Control:
Microcontroller processes the information and outputs delayed signals.
The DACs then convert the digital values back to analog signal.
Speaker Array: Amplifies the signal and sends it through four speakers

11. Design: Control Module – Microcontroller
Inputs:
IR tracking information
Digital input sample from ADC
Operations:
Calculates time delay for four signals
Sends digital values of the delayed samples to the DACs
A timer interrupt tells the DACs to update
Another timer interrupt updates the location information of the IR source
Source: [3]

12. Design: Modules
Signal Input: ADCs convert the input analog signal into digital values
IR Receiver: Detects IR source in the room and sends the location to the microcontroller via I2C
Control:
Microcontroller processes the information and outputs delayed signals.
The DACs then convert the digital values back to analog signal.
Speaker Array: Amplifies the signal and sends it through four speakers

13. Design: Speaker Array Module
Power amps
Capable of delivering up to 10W
Has adjustable gain
Speakers
4 inch, 8Ω speakers
150Hz-20kHz
Source: [4]

14. Physical Design The speakers were placed 23.3cm apart
Allows for 3° of accuracy when steering the signal

15. Conclusion What worked: Interfacing between modules
Ability to delay signals and actively follow listener
Effect was noticeable when playing a single tone

16. Conclusion Future work: Incorporate better tracking system
Current project has intuitive interface for this as a separate module
Faster microcontroller
Experiment with different delay algorithms
More stable connectors between modules

17. References
Dfrobot.com. (2019). IR Positioning Camera For Arduino - DFRobot. [online] Available at: [Accessed 29 Apr. 2019].
Electronic Circuits and Diagrams-Electronic Projects and Design. (2019).Electronic Circuits and Diagrams-Electronic Projects and Design - An Authentic Resource on Electronics. [online] Available at: [Accessed 19 Feb. 2019].
Mouser.com. (2019). [online] Available at: [Accessed 29 Apr. 2019].
Mouser.com. (2019). [online] Available at: [Accessed 29 Apr. 2019].
ti.com. (2019). [online] Available at: [Accessed 29 Apr. 2019].