Chapter 3 Notes


 Audio Mixer - electronic component that allows the technician to select and combine audio sources.       

Inputs:  Two most common types of inputs in an audio mixer are the microphone inputs and line inputs. Microphone inputs can be for either high or low impedance microphones or both.  Inputs can also be for CD players, audio cassette players, VCR’s and MP3 players. 

Level Controls: Controls on audio mixers make sounds louder and others softer.  Two types of level controls are the fader bars and potentiometers or “pots”.  Fader bars slide vertically (up and down).  Potentiometers (pots) move clockwise or counter clockwise.   

Volume Unit Meter or VU Meter: Indicates the strength of an audio signal.  Audio inputs should peak at 100% and never go over that level.  Two types of VU meters are LED and Analog.   In LED VU Meters, green lights are safe and lights above 100% are red.    Analog VU Meters have a needle that moves like a car's speedometer.  As audio levels increase the needle moves to the right.    

Outputs:Mixed audio can be output to VCR for recording, public address system, audio system for recording.  

Trim: An audio mixer control that lets the technician adjust the level of individual microphones.   

Balance (Pan): The balance control is a button on audio mixer that lets the technician send each input to either the right or left channel on a stereo audio mixer.   

Equalization (EQ): Controls the amount of bass, midrange and treble tones in each audio input.   

Mute: On-off button near input fader bar that instantly mutes that input.   

Cue: Button on audio mixer that lets the technician hear through headphones to check if audio is cued to the right place without the audience hearing the music or sound being cued.   

Send: Button on audio mixer that creates a separate audio output.   

The following sources are often connected to an audio mixers line inputs:  VCR, CD Player, audio cassette player, MP3 player, DVD player, computer   

Four types of connectors used in audio equipment:  1.) XLR - typically found in low impedance microphones 2.) 1/4 inch phone plug - used by high impedance microphones 3.) RCA phono - connects audio sources to audio mixers and home stereo equipment.  Capable of carrying only one signal, need two (a pair) for a stereo signal.  A pair of RCA phono cords is called a patch cord. 4.) 1/8 inch mini-jack - similar in shape to phone connector only smaller.  Used in portable stereo equipment.   

Adapters convert type of connector to meet your audio mixer's input jack.  Adapters don't change impedance.   

Matching line transformers change impedance.   

Audio dub - The process of erasing an old audio track and replacing it with a new one.  .

Production music – Music you can use in your projects that you create yourself or is provided by the editing software so you don’t have to worry about copyright infringement.  Garage Band (Mac)/ SmartSound (Adobe Premiere). 



Commercial - A paid advertisement on radio or television promoting  a product or service. 

Target audience/target group  - The main group of people that the commercial is trying  to reach and convince to buy the product or service.  

Message-  The central idea that the creators of a commercial want  the target audience to believe.   “This face cream will make you look  younger and feel more attractive”   

Logo  -  A mark or symbol that represents a company or product.  Logos can include visuals or letters or both.  

Slogan -  Short and memorable phrase used to promote a product. Ex.  Nike's - “Just do it” / “Better ingredients, better  pizza”  Papa John's  

Celebrity  endorsement  - When a famous person talks about the good qualities of a product to promote it. 

Testimonials - When a private citizen (regular person) talks about the good qualities of a product to promote it.  

Voice-over - Narration or commentary. When we hear the person  speaking, but we do not see them.  Instead we see  video of what they are talking about.