1. Mixing Consoles Designations Inputs Outputs Signal processing

2. Sound Control Mixer - Heart of the Audio System  Mixer - Heart of the Sound system  Sound Board, Audio Console, Mixing desk  Main tool of the operator (Board Operator)  Basic Purpose - Controls  What is it - Selects audio signals from various sources  Devices are connected to input channels  Microphones  Output channels of CD players, MD players, DAT players, computers  How Loud will it be - Controls signal level (volume)  Where is it going - Sends audio to various locations  Devices are connected to outputs  Power amplifiers  Input channels of MD players, DAT players, Computers

3. Sound Control Mixer - Heart of the System  Mixer Nomenclature (Functional Description)  8x2 = 8 inputs and 2 outputs  16x4 = 16 inputs and 4 outputs  16x4x2 = 16 inputs, 4 group of sub outs, 2 main outs. Can be used as:  16 ins mixed down to 4 sub mixes, mixed down to 2 output channels (recording studio or concert presentation) utilization  24x6 (Theatre type utilization)  16x4x2x1 – adds a mono output  Also can be referred simply by the number of input channels ex. 8, 16, 24, 48 etc…

4. Cue Control Audio System – Sources, Control, Destinations Equipment System is the Primary Tool of Modern Theatre Sound Design:  Block Diagram - Foreigner Setup Upstage L/R Cluster Radio Record Player MD 1 MD 2 Cass Computer Mixer Amp 1-2 3-4 5-6 7-8 Input Channels 1 - 2 L/R Mono 3 Group/ Outs

5. Input Buss This is the section where audio signals from microphones and/or playback equipment enters the mixer This is the area where impedance matching and Balanced / Un-balanced lines must be carefully watched The input buss typically starts at the rear of the console with either XLR or ¼” RTS connectors

6. Input Buss

7. Rear view of a Mackie t24

8. Input Buss The front side of the console will differ from manufacturer to manufacturer but they will have most of the same components The input channel will usually be arranged to follow the virtual signal path

9. Input Buss Pre-amplifier Pre-amp, trim, trim pot, gain Used to bring a microphone level signal up to line level for easy manipulation within the mixer Also used to adjust the line level inputs from other sources Pad or Attenuator A switch which will lower an inputs level by a set amount Usually used in an input device is too “hot” or much too high a level

10. Close up of Pre-amp section Input channel # Pad / low end roll off Gain adjust

11. Equalization section Onboard equalization control will vary greatly Simple “tone” control Simply varies the balance between high and low frequencies Treble and Base Boost or attenuate high frequencies (treble) or low frequencies (base) Only adjusts a preset range of frequencies Hi – Mid – Lo A fancier version of treble and base control 5 band EQ Able to boost of attenuate 5 different ranges of frequencies Parametric EQ Able to select which frequency range to control and then boost or cut it

12. Equalization section High freq. control High-mid with selectable frequency range Low-mid with selectable frequency range Low frequency control

13. Auxiliary Sends Next in line comes a number of Aux sends Typically 4 to 8 individual busses Some or all will be pre or post fader selectable Pre-fader – the signal strength (volume) coming from the aux send channel will be independent on the position of the channel fader Post-fader – the signal strength coming from the aux send will be dependent on the position of the channel fader Often labeled as PFL (Pre-Fade Listen) Often used to send signals to other devices External effect processor  Reverb or echo Monitor amp/speakers for performers

14. Auxiliary Sends 8 individual aux send channels Note the pre-fade switch

15. Signal Routing Each input channel will be assignable to one or more output channels Very often one selector button will assign the input to two separate outputs 1-2 or 3-4 for example The Pan Pot (Panoramic Potentiometer) adjusts the level of signal going to each of the pairs Example: With the pan pot centered and 1-2 selected, the entire signal is sent to outputs 1 and 2 equally. If you turn the pot to the left, more signal will be sent to output 1 than output 2 This is usually to be avoided for theatrical use Look for single output selection control if possible PFL – Pre-fade Listen. Sometimes called “solo” Usually available to send the signal to a studio monitor or headphones to allow operator to listen to channel without having to send it into the house Channel Mute – turns the channel off. Useful when using wireless mics

16. Signal Routing Pan Pot Output selection Mute Note: PFL not available on this model

17. Other input controls Phantom power A 48v DC power supply applied to the mic input lines Used to power condenser mics (to be discussed later) Phase reverse Inverts the signal coming to the inputs Used if pins 2 and 3 on a mic cable are reversed for example Ground lift Removes the ground connection at the console from the input cable Used to help eliminate ground-loop noise  To be discussed during troubleshooting

18. Output Section This is the area where audio signals will leave the mixer, heading toward Effects processors EQs, delay units, reverb units, recording devices Power amplifiers and eventually loudspeakers Output plugs will typically be Balanced XLR line level Balanced RTS line level Unbalanced ¼” phone plug line level Unbalanced RCA plug line level

19. Output Section Sub or group outputs Auxiliary outputs Left, Right and Main outputs

20. Output Section Sub-group output faders Sometimes called groups, subs or submasters Act as a master fader control for any inputs assigned to it Typically these are cabled to power amplifiers Main outputs Sometimes called Left-Right, Stereo or Mix Essentially two additional outputs, where the manufacturer has taken a guess as to what the end user will use them for Sub groups can usually be combined and selectively assigned to the main output Master output Sometimes called Mono The main outputs can be combined together and controlled from one master fader

21. Aux-Output Section Aux out gain control Aux out mute switch After fader listen

22. Group-Output Section

23. “Flying Faders” Automated mixers are becoming more and more common Started simply to record levels in recording studios Often had 60 or more inputs levels to write down and could have many many setups. Flying faders would remember where the faders were set and you could restore to any setting with the push of a button

24. “Flying Faders” Today mixers are capable of remembering output selections, EQ settings, pan settings etc. For live mixing it is REQUIRED to still have actual faders which an operator can move Performers will never do the exact thing every night The board operator must be able to easily make adjustments to levels on the fly

25. For Next Class Read P. 82 – 90, Leonard Processing Devices, Kai’s Sound Handbook