VID102 DAY 3

1. VID102 DAY 3

2. Class Schedule Schedule Change Viewing Examples Audio Principles

3. Methods of Transduction Electromagnetic Electrostatic/capacitance Ribbon

4. Signal Level Types • Microphone • Weaker signal, requires a pre-amp • Mic level • 2 mV to 1.2V • Professional Line • +4dBu 1.23 V • Consumer Line • -10dBu .316V • Speaker • 4V

5. Connectors and Cables • XLR • Balanced • 3 conductor • ¼ Inch • 2 or 3 conductor • Balanced or unbalanced • Balanced • Minimizes noise and rf interference, uses phase inversion, helps with longer cable runs • Unbalanced • No shielding

6. Headroom The amount of give between your average level and the point of distortion Clipping is the point at which you exceed your headroom and the limitation of the medium, resulting in distortion

7. Signal to Noise Ratio You want to have more signal then noise Noise is inherent in the environment and in the equipment

8. Polar Patterns Way in which a microphone will pick up the sound This is influenced by the type of transduction Choosing the right polar pattern for the right situation

9. Omni

10. Cardioid

11. Hyper-cardioid

12. Super-cardioid

13. Bi-directional

14. Sound Theory • Types of Transduction (Microphones) • Describes the way in which the microphone converts a sound source into an electrical signal. • Speakers do the reverse, an electrical signal is turned into an acoustic amplified sound • Electromagnetic • Electrostatic/Capacitance • Ribbon

15. Sound Theory • Types of Transduction (Microphones) • Electromagnetic • Dynamic microphone uses electromagnetic induction • A small movable induction coil, positioned in the magnetic field of a permanent magnet, is attached to the diaphragm. When sound enters through the windscreen of the microphone, the sound wave moves the diaphragm. When the diaphragm vibrates, the coil moves in the magnetic field, producing a varying current in the coil through electromagnetic induction. • Commonly used to capture loud percussive sounds with very strong transients. • Does not require an external power source

16. Sound Theory • Types of Transduction (Microphones) • Electrostatic/Capacitance • Require 48v Phantom Power • The diaphragm acts as one plate of a capacitor, and the vibrations produce changes in the distance between the plates. •  variety of polar patterns • Good at capturing full frequency sounds, captures subtle dynamics of a performance • Frequency Response is better • Ribbon • use a thin, usually corrugated metal ribbon suspended in a magnetic field. The ribbon is electrically connected to the microphone's output, and its vibration within the magnetic field generates the electrical signal. Ribbon microphones are similar to moving coil microphones in the sense that both produce sound by means of magnetic induction.

17. Microphone Specifications • Usually they are categorized by type of transduction and polar pattern • Polar patterns describe how a microphone will pick up a sound source. • Omni • Cardioid • Hyper-Cardioid • Figure-8 • MS

18. Omnidirectonal low coloration; they add very little to the original sound. Being pressure-sensitive they can also have a very flat low-frequency response down to 20 Hz or below. Pressure-sensitive microphones also respond much less to wind noise and plosives than directional (velocity sensitive) microphones Pick up sounds equally from all sides

19. Cardioid named because the sensitivity pattern is heart-shaped. Good rejection 180 degrees off axis (rear) Pickup equally from the front and the sides Subject to the proximity effect (closer you are to the source, the lower frequencies will be emphasized) Fairly directional

20. Super-Cardioid/Hyper-Cardioid Good rejection from the sides But some pickup from the rear Fairly directional

21. Shotgun • Good rejection from the sides • Narrower pickup from the rear • Highly directional • Most Boom Microphones • Usually have interference tubing to phase cancel the sides and make more directional

22. Figure 8 Picks up from the front and rear Hole in the center Commonly used for M/S miking technique M/S or Mid Side is a stereo miking technique which combines a figure 8 with a cardioid microphone, it provides a wide stereo image and when listening on headphones you get a sense of panning better then traditional stereo miking techniques.

23. Intro to Production Audio Process of recording audio on set Starts in pre-production Specific crew positions Goal is to capture the cleanest possible recording of set dialogue

24. Location Scouting • The process of evaluating a location based upon the sound • What will prevent you from capturing clean dialogue • What can be done to help you capture clean dialogue • What microphones should you use?

25. Script Break Down • Analysis of the script with a specific focus on sound • Consider possible miking approaches • Start thinking about post production • Number of actors • What equipment will be needed • What are possible problems for sound?

26. Production Audio Crew Production Mixer Boom Operator Video Assist Utility

27. Production Mixer Request Gear Package Goes on the Scouting of locations Is responsible for running the mixer, the recorder, and taking sound reports

28. Boom Operator Is the on set Ninja Places microphones Responsible for positioning them selves optimally for capturing dialogue without being seen in the frame.

29. Utility and Video Assist Utility is responsible for cable wrangling, batteries, helping the mixer, sometimes being a second boom op Video Assist helps set up monitor feeds for the mixer

30. For Next Class Read Chapters 3 and 4 Assignment #1