Live Audio, Staging, and Vision Review

Practice flashcards covering Audio Theory, Hardware, Staging Types, Knots, and Vision Systems based on CUASOU301, CUASTA301, and CUAVSS302 lecture notes.

How is sound distinguished from audio in the transcript?

Sound is vibrations through the air, while Audio is the deliberate capture, recording, alteration, and playback of sound.

What is the definition and standard unit for frequency?

Frequency is the speed at which waves travel, measured in Hertz ($Hz$), which represents the number of cycles per second.

How is amplitude measured and how do humans perceive it?

Amplitude is the height (maximum displacement) of a wave, measured in Decibels ($dB$); humans perceive it as loudness.

What is the technical difference between balanced and unbalanced cables?

Balanced cables use three wires (two signal, one ground) to cancel noise through phase inversion, while unbalanced cables use two wires (one signal, one ground) and are susceptible to hum over $5\,m$.

What are the common uses and characteristics of the Shure SM58?

It is a dynamic, cardioid vocal microphone that requires no power and has good rejection from behind.

What is a major common misconception regarding BNC?

That BNC is a cable; it is actually a connector most often used with coaxial cables.

How does a dynamic microphone generate voltage?

A sound wave moves a voice coil within a magnetic field, which generates an $AC$ voltage.

What are the power requirements and characteristics of condenser microphones?

They require power (battery or phantom power) because they use a metal diaphragm and backplate to form an electrical capacitor; they are more sensitive and fragile than dynamic mics.

What is Intermodulation distortion (IMD)?

Intermod occurs when multiple $RF$ signals interact in non-linear circuits, generating unwanted mathematical sum-and-difference frequencies.

What are the three key components of a signal flow diagram?

1. Inputs, 2. Processors, 3. Outputs.

What is the correct power-up sequence for an audio system to prevent damage?

1. Audio desk, 2. Effects/media players, 3. Wireless systems, 4. Amplifiers.

What is the difference between Mic level and Line level voltage?

Mic level is the weak voltage generated by a microphone (thousandths of a volt, $-60$ to $-40\,dBu$), while Line level is approximately one volt ($1000\times$ stronger).

What are the standard measurements for consumer vs. professional line levels?

Consumer equipment is $-10\,dBV$ and professional equipment is $+4\,dBu$.

What formula for feedback is provided, and what are the solutions?

Too much gain equals a mic being 'too hot'; solutions include reducing gain, using EQ to reduce offending frequencies, or repositioning PA/mics.

In stage geography, explain the origin of 'Upstage' and 'Downstage'.

In early Greek theatre, stages were raked (slanted) downward toward the audience for visibility; 'up' meant moving up the slope away from the audience, and 'down' meant moving down toward them.

What defines a Thrust stage?

A stage that extends into the audience space so that the audience is positioned on three sides ($180^{\circ}$ around).

What is the difference between weight-bearing and non-weight-bearing scenery?

Weight-bearing scenery can hold human bodyweight (e.g., platforms, stairs), whereas non-weight-bearing scenery is used for background (e.g., flats).

What is a French Brace in staging?

A wooden right-angle-triangular brace hinged to a flat, providing more solid support for large flats than a standard stage brace.

What is the required weight for counterweights in a manual fly system?

The counterweight must be a minimum of $1.5\times$ the weight of all items flown.

What is the common etiquette for using comms during a production?

Do not chat, speak quickly and clearly, use the phrase 'StandBy' before a cue, and use 'Go' as the only word to initiate a cue.

Describe the function and use of a Bowline knot.

A fixed loop knot tied at the end of a rope that will not slip or jam under load but unties easily; used for mooring, rescue, or hoisting light loads.

What is Keystone Distortion and how is it fixed?

Distortion and unequal aspect ratio caused by a projector being 'off axis' from the screen; it is fixed using the keystone correction function to restore a rectangular image.

What signal is carried by a Composite Video cable and what connector does it use?

It carries chrominance (colour) and luminance (brightness) over a single wire, typically using RCA connectors.

How is the light output of a projector measured?

In Lumens.

What is the VGA (Video Graphics Array) standard and its physical characteristics?

An analogue $15$-pin connector with screws, capable of supporting up to $10\,kg$ on high-quality cables.