Mic Technique Flashcards
(33 cards)
How does a dynamic Mic work?
- lightweight diaphragm attached to small coil
- coil suspended in magnetic field
- vibrations in air cause movement in diaphragm and coil
- produces small A.C current
What are the benefits of using dynamic mics?
- simple construction
- robust, cheap and reliable
What are dynamic mics used for?
- loud instruments
- hostile environments
How does a capacitor (condenser) mic work?
- uses principle of capacitance
- diaphragm is one plate of capacitor
- capacitor holds charge
- charge held = proportional to distance between plates
- needs phantom power (48v)
What are the benefits of using a condenser mic?
- ## lightweight diaphragm gives good HF response
What are condenser mics used for?
- critical recording,
- quiet delicate instruments
- vocals
How does a Ribbon mic work?
- same principles as dynamic
- lightweight + delicate strip of corrugated aluminium
What are the 4 possible polar patterns?
- Omnidirectional
- Cardioid
- Hypercardioid
- Figure-of-Eight
What is an Omnidirectional polar pattern?
Equally sensitive from all directions.
What is a Cardioid polar pattern?
Front & Side sensitivity
What is a Hypercardioid polar pattern?
Similar to cardioid, less side sensitivity, some rear pickup
What is a Figure-of-Eight polar Pattern?
Front and rear but no side pickup, front and rear are 180 degrees out of phase
What polar pattern do you get when you combine omni & fig8?
Cardioid
What polar pattern do you get when you combine Omni + 0.5 x fig8?
Hyper Cardioid
What polar pattern do you get when you combine two cardioids?
Omni-directional
What polar pattern do you get when you combine cardioid - cardioid at 180 degrees?
figure-of-eight
What polar pattern do you get when you combine cardioid & fig8 at 90 degrees?
cardioid 45 degrees to the left
What polar pattern do you get when you combine cardioid - fig8 at 90 degrees?
cardioid 45 degrees to the right
What is an X-Y Blumlein stereo setup?
Pair of crossed fig8, pair of cardioids at 90 degrees.
What are the pros & cons of X-Y setup?
Pros:
- complete mono capability
Cons:
- No time of arrival info
- with fig8s, rear out of phase
- with cardioids there is spatial distortion at thirds in image
What is an ORTF Stereo Setup?
Similar to X-Y, angled at 110 degrees, capsules 17cm apart.
What are the Pros & Cons of ORTF setup?
Pros:
- good time of arrival info
- good for reproduction on headphone
Cons:
- Phase & Spatial issues
- possible hole in middle if too close
What is a Binaural Stereo setup?
Dummy head with microphones replacing human ears
What are pros & cons of Binaural setup?
Pros:
- Very accurate and realistic on headphones
- time of arrival info fully integral
Cons:
- Phase and spatial issues on speakers
