10. Final Exam (Spring'22)

1. What makes a computer a computer?

   • How Computers Work (27min of short videos in a playlist)

2. What is a transistor, what did it replace, and why is it the most important invention of the 20th Century?

3. Describe the difference between “open” and “proprietary” file formats and how that plays into “digital obsolescence”. What is a “proprietary” music notation file format? What is an “open” music notation file format?

4. Provide a drawing that illustrates a time-domain waveform representation of a sine wave (label the following on your drawing: compression, rarefaction, zero crossing, amplitude, and wavelength).

5. Define complex tone (or complex wave form) by comparing it to a sine wave.

6. What determines pitch?

7. What unit is used to indicate a ratio of the following?:

   • what humans perceive as silence to how loud a sound seems to be to a human

8. What is the frequency range of human hearing?

9. How is a spectrogram (frequency domain) different than a waveform (time domain)?

   • 3d Spectrogram in Chrome

10. What is proper gain staging (or proper gain structure) for live sound? (talk about the steps you would take to find the proper level for each part of the system — from mic to speaker)

    • *First* turn off amplifiers (main speakers and stage monitors are often "active" which means they have amplifiers inside the speaker)

    • on the mixer

      1. set channel volume faders and main outs to Unity (ØdB)

      2. set the preamp gain knob to lowest setting

      3. with headphones (or just visually) set proper gain structure for each channel:

         1. press PFL/SOLO button on the channel

         2. engage HPF if source has no low end (always engage for vocals)

         3. slowly bring up preamp gain knob as performer sounds into the mic until the VU meter averages around -18dB and never peaks at higher than -6dB

         4. unSOLO the track and perform the three steps above with the next channel, etc.

    • *Last* (after all channels have been setup individually) have everyone perform together and with volume knob of amplifiers (main speakers and stage monitors) turned all the way down, slowly turn up volume knobs on amplifiers until you reach the desired volume in the space.

11. Explain what a preamp does.

    • note Voltage Levels in Audio Gear

    • see Understanding Signal Levels

    • see What is a Preamp

12. Define clipping (or distortion). Draw it.

13. What is feedback and what are some ways to avoid/lesson it?

    • reasons for feedback:

      • mic too close to PA speaker

      • mic too far from source being amplified

      • too many mics

    • ways to minimize feedback issues:

      • experiment with the placement of a microphone

        • the closer the microphone is to the source the more the preamp gain can be lowered

        • placing the speakers between the microphone and the audience (speakers along the front of the stage) can greatly lesson feedback issues because the microphone will not pickup its own amplified signal

      • use directional mics to isolate sounds being picked up

      • add acoustic treatment (absorption) to especially "live" rooms with many hard surfaces

      • add an audience! (rooms without an audience sound very different than rooms with no audience)

      • use a spectral analyzer to identify feedback frequencies and fine tune EQ

14. How does analog-to-digital (ADC) and digital-to-analog (DAC) conversion work? (you must use the following terms in your definition = samples, sample rate, and bit depth)

    • How Digital Audio Works (MSP documentation by Cycling'74)

    • https://www.izotope.com/en/learn/digital-audio-basics-sample-rate-and-bit-depth.html

    • What is a sample? = https://www.sweetwater.com/insync/sample/

15. Write the following out with blanks filled in:

    • An analog signal is a continuous signal; analog signal values are known for all moments in time.

    • A digital signal is discrete a signal; digital signals are only known at certain specific times.

16. Define and discuss when you use lossless audio files (and give examples of lossless file types).

    • see Computer in Audio Recording (in Appendix)

17. Define and discuss when you use lossy audio files (and give examples of lossy file types).

    • see Computer in Audio Recording (in Appendix)

18. Discuss the difference between a MIDI file and a WAV file. What type of information is stored in each file?

19. How is a MIDI controller different from an analog synthesizer?

20. How do the acoustics and noise present in the recording space effect mic placement when recording? (For instance: Where would you place the mic if you didn’t like the space and didn’t want the characteristics of the space to be apparent in the recording?)

    • see Mic Placement in Audio Recording (in Appendix)

21. Explain proper gain structure (or staging) in the recording process. What two levels are you looking for on the level meter when you are recording?

    • see Gain Staging in Audio Recording (in Appendix)

section1 / section 2

1. matthew vlcek / annie

2. cat / amy

3. matthew vlcek / annie

4. matthew davis / ben

5. matthew davis / ben

6. joniel / everett

7. mary / hutch

8. joniel / everett

9. cat / amy

10. brice / jonny

11. sadie / gray

12. sadie / gray

13. garrett / sasha

14. zoe / matilda

15. zoe / matilda

16. caleb / jameson

17. caleb / jameson

18. andrew / tori

19. andrew / tori

20. carolina / abby

21. carolina / abby