Balanced Audio, Speakers, and

AmplifiersCreated by: Sarah Hutchens & Jacob Hanchett

What is balanced audio?

● Method of minimizing unwanted noise from interference in audio cables.

● Uses an extra line:○ Hot line (positive)○ Cold line (negative)○ Earth line

How does balanced audio work?

● Two identical signals, which are opposite polarities, will cancel each other out.

● Cables used in these systems are designed to:○ carry two versions of the signals○ manipulate the polarities of these signals to

eliminate noise

Unbalanced Audio

● Use only two lines to transmit the audio signal○ Hot line (which carries the signal)○ Earth line

● Common in short cables● Common in less professional

applications● Any single-pin connector used for audio

is unbalanced

Speakers

● Speakers are the final translation machine

● Voltage and amplitude change the sound

● Takes the amplified electrical signal and translates it back into physical vibrations, by the drivers, to create sound waves

Parts of a speaker

Types of Drivers

● Woofers○ Biggest drivers ○ Produce low frequency sounds

Types of Drivers Cont.

● Midrange○ Produce a range of frequencies in the middle of the

sound spectrum

Types of Drivers Cont.

● Tweeter○ Smallest driver○ Produce the highest frequencies

Amplifiers

● Amplifies the strength of the electrical signal● Signal is sent to the speaker● Changes alternating current (AC) into direct

current (DC) to work properly ● The electrical signal from the microphone is

not strong enough to make the speakers work

Amplifiers Cont.● Transistors

○ Heart of most amps○ Uses conductors and semiconductors○ It boosts the voltage

Amplifier Circuit

Summary ● Use the correct wires for the best

sound and safety of the equipment ● Speakers change the electrical signal

back into sound by vibrating the drivers

● Amplifiers amplify the strength of electricity

Bibliography

● www.mediacollege.com● http://www.howstuffworks.com/amplifier.htm● http://www.howstuffworks.com/speaker.htm

Thanks for listening! Hope you learned a little something about balanced/unbalanced audio, speakers and

amplifiers!