1. Lecture 28
Closing it Out

2. This Week Today Friday Student Survey (15 minutes)
The comments will be very important for future development of this approach to physics teaching.
Return Examination #3
Complete the electronic side of music
COLLECTION OF PODS (End of Hour)
Friday
Any spill-over from Wednesday
Complete Pod collection (Else $50.00 or no grade)
Brief Review for Final
It’s OVER!!

3. MONDAY Final Examination MONDAY, December 6th 7:00 AM to 9:50 AM
Room 359 (here)
GRADES SHOULD BE POSTED BY THURSDAY.

4. We were talking about…..
Speakers

5. Different Speakers for Different Folks
Subwoofer
Woofer
Mid Range
Tweeter
LOW

6. Frequency Ranges for different types of speakers.

7. The “People Process” Sound Production Microphone Amplifier Recorder
Digitize
A/D CD
D/A
Amplifier
Speaker(s)

8. Remember The Guitar?

9. Or Similar Stringed Instruments?

10. Another Music Application

16. The Strings

17. causes a current to flow The current is the audio
How?
Field in and around the
magnet changes and
causes a current to flow
in the wire.
The current is the audio
signal.

18. The “Package”
A Combination
Amplifier
and
Speaker
The Instrument

19. Multiple Sources of Sound

20. 2004 Synthesizer

21. 1955 RCA

22. 1970 Moog Synthesizer

23. In your home (PC)

24. The Music Signal - Real

25. Start with a stored “sample”

26. How does a real sound vary?

27. A Synthesized Note for an instrument
Mix the two together
A Synthesized Note for an instrument

28. MIDI
The MIDI protocol allows electronic devices (usually synthesizers, but also computers, light show controllers, VCR’s, multi-track recorders, etc.) to interact and work in synchronization with other MIDI compatible devices.
Using a master controller device such as a keyboard, one can play or trigger sounds from other electronic devices remotely.

30. The Computer Thingy We have a voltage signal.
We want to “code” it into digits (0,1)
We want to COMPRESS the string of bits into a shorter one.
Lots of methods.
Most Popular is MP3

32. Analog  Digital

33. The CD Player

35. Side View

36. The Path

37. The Data

38. The “Thing”

39. And out comes
MUSIC !