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