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Signal Flow . The most important thing about sound.What makes the noise, what effects the noise, what amplifies the noise, and what reproduces the noise and in what order. Transducers - Microphones, Keys, Etc.. Microphone Types and Placement. OmnidirectionalCardioidSupercardioidHypercardioid.
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1. Basics of Sound Systems and Acoustics
Georgia Church Music Conference
2006
4. Microphone Types and Placement Omnidirectional
Cardioid
Supercardioid
Hypercardioid
5. Omnidirectional Microphones These are the microphones that pick up more-or-less from every direction. Useful if you wish to pick up ambient sound.
"Only have the mic on when you need it!!!"
6. Cardioid Family Cardioid microphones accept sound from one direction but reject sound from another. Their polar pattern in in the shape of a heart, rejecting sound from the back of the microphone.
7. The super cardioid mics have a similar same pattern, but have a more narrow shaped with a lobe at the rear of the microphone.
A hyper cardioid has an even narrower shaped pickup pattern.
This is useful when you want to capture sound from say a stage and not the audience. In a concert situation, you may want to catch the sound of the singer but not the sound from the monitor to help resist feedback.
8. Pattern Guide
9. Placement Pastor- Staff
Ear, Belt Pack (lapel)
Choir, Chorus (1:3 ratio)
Microphone Stands, Overhead
Instruments
Brass, Winds, Strings, Acoustic Guitar, Electronic Instruments (Keys, Bass, Etc), Drums.
Recording
Natural Sound is best
Direct
10. How Critical is Critical Distance Critical distance (Dc) is the point where the direct sound from the source equals the reflected sound from the room.
Feedback
Shallow, Hollow sound
Poor intelligibility
11. Dynamic Vs Condenser Dynamic Microphones
Actual energy to energy transfer 1:1
Accurate representation
Low cost
More durable than other types of mics
Less sensitive (smaller sound field)
12. Condenser microphones
Amplified transfer of energy 1: 2~?
MUST HAVE PHANTOM POWER
Extremely accurate
Very sensitive (larger sound field)
Less durable (humidity and shock)
Some mixers have Global and some isolated.
Check choir mics, podium mics, etcSome mixers have Global and some isolated.
Check choir mics, podium mics, etc
13. Speaker Types Point Source --- (-6dB per doubling of distance, i.e.-inverse square law) Dispersion angles very important
2 way
3 way
Subwoofer (is not God)
14. Line Arrays A Line Array in the truest sense is literally a straight line. --- (-3dB per doubling of distance) Line Arrays are cool, but not the best in many applicationsLine Arrays are cool, but not the best in many applications
15. Many variations of a Line Array exists.
True Line
J Line
Curvilinear Array (JBL VRX900 and Similar)
16. Horizontal Arrays Very even horizontal coverage with expanded vertical coverage.
Less expensive than Line Arrays.
Reduced “comb filtering”
Shorter throw distance
17. Cables and Connectors XLR (Microphone Cable)
Three pins, Balanced connection.
Pin 1 Shield or ground
Pin 2 Hot or Positive
Pin 3 Negative or neutral
TRS (balanced Ľ”, stereo instrument)
Three pole, Balanced connection
Tip, Ring, Sleeve
Tip – Positive or Hot
Ring – Negative or neutral
Sleeve – Shield or ground
18. Unbalanced Ľ” (basic instrument cable)
Also known as a radio antenna
Two connections
Tip – Hot or Plus
Sleeve – Negative and shield
Balanced Ľ” is by far better and more accepted.
19. Microphone Cable
Small gauge 3 connector
Speaker Cable
*Speakon Connector*
Heavy gauge 2 connector
Signal loss is a factor.
Instrument Cable
Stereo Vs Mono
TRS (Balanced)
1/4” (Unbalanced)
20. Signal Flow - Troubleshooting
The most important thing about sound.
What makes the noise, what effects the noise, what amplifies the noise, and what reproduces the noise and in what order
22. Troubleshooting Is the power turned on?
Start at the very bottom of the “food chain” the transducers. microphones (signal source)
Move forward taking into account all connections and cabling
Try to isolate the one piece of equipment that is causing the problem
23. Mixing Channel Strip Trim/ Gain
EQ
Hi Pass
Hi
Hi- Mid
Sweep
Low-Mid
Low
Low Cut
Aux Sends Separate Mix for Monitors and Recording
Pre – Post Fade
Pan
Assignment Button Sub Groups (Blending)
Mute Groups/ Mute
Slider
24. Basics of Acoustics What is Sound?
25. Frequency - Hz Frequency is the number of pressure peaks that pass a given point in 1 second,
Average hearing range is between 20Hz and 20,000 Hz.
Middle C on piano is 256Hz
27. Control of Sound Consider wavelengths
Acoustics are physical properties of air movement
To control or effect sound, the wavelength must be smaller than the actual physical properties of the object or enclosure.
Subwoofers
Cars
28. Reverb vs. Echo Reverb is the decay of sound. (mostly indirect)
Cathedral
Echo is the direct reflection of a sound.
Two parallel side concrete walls
Not to be confused with Feedback.
29. Acoustic Treatment Absorption
Reduces the total amount of reverb
Diffusion
Not necessarily used to reduce reverb but to cut echo.
Diffsorbers
Good Architectural Design is less expensive than acoustical treatment
30. Resources www.synaudcon.com (Syn-Aud-Con)
www.shure.com
www.crownaudio.com
www.churchsoundcheck.com
www.messengermediainc.com