Unit 4 – Equipment

Day 1

Microphones• Transducer – device that changes one form of

energy to anotherConverts voice into audio signal

• TypesDynamicCondenserRibbon

• PatternsOmni DirectionalBi-DirectionalCardioid

Dynamic “Moving Coil”

• Waves strike diaphragm, which is connected to coil• Coil is suspended in magnetic field• As diaphragm moves, coil moves and because it is in a

magnetic field, an electrical current is produced matching the original waves

• Characteristics:Very rugged, can withstand abuseUsed in field recordings (outside)Accurate voice reproduction, good frequency responseHandle high volumes wellReasonable budget range

• Types:• Electro-voice RE 20, Electrovoice RE-50,

Condenser “Capacitor”

• Internal front plate (diaphragm like), Fixed back plate, Electrical circuit

• Both plates are charged• When waves hit front plate, the distance between the plates

changes• This causes a change in voltage between plates which produces

electrical current matching original waves• Characteristics:

Popular in studio settingsHigh Quality, produce signal of exceptional warmth and clarityRequires phantom power (battery, or external supply)Loud outputFragile

• Types:AT8010

Ribbon• Metallic ribbon suspended in a magnetic structure

(similar to dynamic)• Characteristics:

Popular in old daysSmooth, warm qualityExtremely fragile

Omni-Directional• Picks up well in all directions• Sounds like “you are there”• Picks up more ambience• Forgiving mic placement• Less handling noise

Bi-Directional• Picks up front to back• Good for interviews where you want both

speakers

Cardioid• Picks up from one direction• Focus on centered subject• Rejects ambience• Precise mic placement needed• Susceptible to handling noise, wind, and plosives

Miscellaneous Info• Polar Response Patterns are 2-D graphs that

represent a microphone’s pickup pattern

• Windscreens are used to prevent wind noise and plosives

Microphone Technique• Mic to mouth distance of 6 inches (thumb to

pinky)• Not directly into mic, but rather slightly off axis• Align mic with nose and then point it down a bit• “Give a level” – Don’t say “check, 1, 2, 3”, rather

read a sample copy

Mic Fright• Performance anxiety

Butterflies, sweaty palms, dry mouthLeads to higher pitch, running out of breath, faster pitch, lower volume

• Caused by:dislike of voicefearing failurebeing inexperiencedbeing unprepared

• Nothing more than extra energy that you should use in a positive way

Audio Console• 4 Functions

o Selectingo Mixing/Amplificationo Routingo Monitoring

Audio Console• Controls

Buttons (Press)Pots/Knobs (Turn)Slides/Fades (Slide)

• VU MetersIn The RedIn The MudPegging the MeterLED v Needle

• OutputsProgramAuditionAuxCue/Preview

• MonitorsSpeakers v HeadphonesFeedback

Day 2

Broadcast Areas• On-Air Studio (Main Control Room / Auxillary

Control Room)Live studio

•  Production Studios (1-6)Produce and record material that eventually will be on airPSA, PromosCreative center of facility

• Performance/Announce Studio (1-9)-Voice Over, Interviews, etc.

Aesthetics• Avoid Fluorescent lights (they hum, and are

harsh)• Place lights on dimmers• Stools should be comfortable, no squeaks

moveable, and adjustable• Decorations

Ergonomics• Design considerations that help reduce operator

fatigue and discomfort• U-Shaped or L-Shaped layout

Puts all equipment within arm’s reach and allows DJ to execute working combo

DJ is performer and engineer at small stationsAt large stations there may be an engineer assist

• Stand Up or Sit Down• Furniture is the foundation

Equipment sets on it, mounts on it, or is wired through itComputer Monitor should be 2 feet away and fall slightly below

eyesightKeyboards can be placed under counterHousing racks may require cooling

Other Studio Devices• Playback Devices

o Computer - Digitalo CD Player - Digitalo Cassette Deck - Analogo Turntable – Analogo Telephone – Analog/Digital

• Digital Audio Storageo Adobe Auditiono Instant Replayo Delayo Audio Recorders

Audio Chain• Major Categories of equipment• Sound Sources

CD player, turntableMicrophonesDigital Audio Workstation, Voice Recorders, iPods/iPhonesComputers

• Recording Devices / Delay SystemsComputer

• Signal ProcessorEqualizers, Noise reduction, ReverbExciters

• Monitoring EquipmentHeadphones, Speakers

• Transmission SystemTransmitter, Antenna

Day 3

Acoustics• The way sound behaves within a closed space• Reflection

Sound bounces off a surface

• AbsorptionSound goes within a surface

• PenetrationSound goes through a surface

• DiffusionSound is broken up and dispersed by a surface

Heard Sound• Direct Sound is the main sound that we hear• Indirect sound reaches microphone fractions of

seconds after direct sound• “Reflected” sound could be Echo or Reverberation

o Echo – Bounced off 1 surfaceDistinct Repetition

o Reverb – Bounced of 2 or more surfacesConinual Decay

• Reverb Ring/Time – time it takes sound to die out• Reverb Route – path sound takes from source to

reflection and back to mic• Reinforced Sound – Causes objects within studio to

vibrate

Heard Sound• Dead Studio = Short Ring / Long Route• Live Studio = Long Ring / Short Route• Abosrption Coefficient = amount that will be

absorbedo 1.00 = all sound will be absorbedo 0.00 = no sound will be absorbed

Studio Shape and Size• Parallel walls produce more reflected sound than

irregular• Standing waves = combination of a sound wave

going in one direction and its reflected wave going in the opposite directions

Undesirable effect created

• Avoid cubic designs• Splay walls at non 90 degree angles

Live Studio• Microphones are wired so that when it is turned

on, the studio light turns on• Many times talent will use hand signals when

inside of a “live” studio

Sound Properties• When something vibrates, sound is generated• Vibration causes air molecules near it to come together,

slightly raising the air pressure, pushing the molecules into motion, which sets others in motion, and so on

• Sound develops waves (like a stone in water) which vibrate up and down

• Push = Compression• Pull = Rarefaction• Must happen in a medium• Commonly Air• Could be water, wood (but that is usually • Must have a receiver to perceive it as sound• If a tree falls in the woods and no one hears it, does it

make a sound?

Day 4

Amplitude• Height of Wave = Strength/Intensity = Volume = Loudness • Greater compression and rarefactions of air molecules occur

Crest higher, trough lowerSubjectiveMeasured in decibles (dB)Silence = 0dB, 10x as powerful = 10dB, 100x as powerful =20db

• Human Threshold of hearing is 0 -• Human Threshold of pain is 120• Above 85 dB can cause hearing loss

3dB = Barely Noticeable, 5dB = Clearly Noticeable, 10dB = 2x as loud, 20dB = 4x as loud

Frequency• # times / sec a sound wave vibrates = # of cycles =

Pitch = HighnessFaster vibration = higher pitch

• Wavelength – measurement between two crests or two troughs

High pitch is short, low pitch is long• Subjective• Measured in hertz (Hz)

2,000 cycles per second = 2,000Hz1,000Hz = 1 kHz20,000 cycles per second – 20kHz3/4 of an inch = 16Khz, 36 feet = 30Hz

Timbre/Tone• Waveform• Pure tone is represented by a sine wave• Basic tone = fundamental• Most sound is combination of many tones

Harmonics = exact frequency multiples of the fundamentalOvertones = not exact multiples of the fundamentalIn-Phase – Peaks and troughs line up (combine into one wave with 2x amplitude)Out of Phase – Peak lines up with trough – cancel each other out

Envelope• Duration = change in volume over period of time• Attack – Builds max volume• Decay – Peak volume to sustained volume• Sustain – Holds sustained volume• Release – Sustained volume to silence

Frequency Response• Range of pitches the speaker or microphone can handle• Low (Bass) = 20 to 250 Hz = power and bottom• Too little = Thin, Too much = boomy• Mids – 250 to 4,500 Hz = substance and intelligibility• Too little = lack of presence, too much = harsh• Highs (Treble) – 4,500 to 20,000 Hz = sharpness and

brilliance• Too little = dull, too much = excess noise and hiss• Octave – doubling or halving the original frequency• 110 – 220 – 440 – 880 – 1760 – 3520 – 7040

Noise & Distortion• Noise – unwanted sound element, not present in original

sound• Signal to Noise Ratio – audio measurement (decibles)

showing amount signal exceeds noiseBigger is betterMost analog are 60 to 1Most digital is 98 to 1

• Distortion – Change in audio signal due to inaccurate reproduction of sound

Most often when signal is recorded at level that is too loud

Sounds muddy, less clarityAnalog is worse at this than digital