SPEAKERS AND SOUNDNathan Grisier
Emmanuel VillarruelPraja Katel
Jackson Lund
What you’ll learn
Sound Interference and Overtones
Amplifiers/Speakers Acoustic Architecture Line arrays
Sound Interference and Overtones
Sound Produced from
vibrations Loud enough for
everyone to hear
Interference Weather Destructive
interference Opposite vibrations
Overtones
Other frequencies besides the fundamental that exist in musical instruments
Different musical instruments produce different overtones
Create individual sound of instruments Most instruments would sound the same
if it weren't for overtones
Instruments
Amplifiers/Speakers
An electronic amplifier that amplifies low-power audio signals to a level suitable for driving loud speakers is the final stage a typical audio playback chain
The History of Modern speakers
Lee de Forest Invented the first
audio amplifier, 1909
Triode Vacuum tube AM radio
Matti Otala Discovered
Transient Intermodulation Distortion (TIM)
How sound is amplified
Sound waves are perceived by the microphone and are then converted into corresponding electrical voltage varying in frequency and amplitude according to pressure of the sound vibrations
Many amplifiers have provision for receiving the signals from several microphones or other sources , combining them, and amplifying the combined program to the power required for the audience to hear easily
History of Acoustic Architecture and design
Roman Era Vitruvius
Wrote “De Architectura”, known today as “The Ten Books on Architecture”.
Beginning of acoustic architecture Renaissance
Opera houses Concert halls Churches
18th Century Experimentation
20th Century Wallace Sabin
Noise Control
A = Absorb Reduces reverberation Porous absorbing materials drapes, carpets, ceiling tiles, etc.
B = Block Prevents sound waves from continuing on
their path panels, walls, floors, ceilings and noise
barriers. C = Cover-up
sound masking white or pink noise
Outdoor Noise Control
Regulating sound levels To much noise can be a health hazard, so rules
have been set in place that engineers have to be aware of when building a venue
Noise barriers Walls that are placed around the venue to try
and prevent the sound from escaping to residential areas
Buffer zones Place commercial/industrial buildings around
the venue rather than residential.
Line Arrays
Why and what are line arrays? Line arrays are a group of speakers, usually 3-
12 or as much as 20, stacked on top of each other and hung at a diagonal angle.
Time delay Sound is a directional waveform and travels
around 1000 ft/sec. causing time the time delay to differentiate between the front row to the middle to the very back row of the venue or concert field.
The job of the sound engineer or technician is to balance
Solving the problem
In order to reach the everyone line arrays are strategically placed on the stage and throughout the audience.
The sound output to the middle row line arrays are put on a time delay In order to find the right time delay, measure
1 milsec/ft from the middle row
Conclusion
next time one of you attend a concert, whether inside or outside, you will be able to understand why the speakers and the music sounds clear and full of life
THE END