INTRODUCTION TO MIXING AND EQUALISATION BY ENGR ALO OLUWAGBENGA

1. INTRODUCTION TO MIXING AND EQUALISATION BY ENGR ALO OLUWAGBENGA

2. OVERVIEW OF PRESENTATION • Introduction • Fundamentals of mixing • Gain setting & Level control • What is Equalisation • Common Types of Equalisation • Output Control & Loudness • Guide line for good EQ

3. INTRODUCTION An Audio Engineer (Sound Engineer) is the person responsible for the technical aspect of Sound recording, PA /sound system(Stage/FOH) or Broadcast(Radio/TV). They operate the equipment( eg microphones,mixing console…etc) to ensure highest audio quality(fidelity). This is done by Mixing, Equalisation and sound processing.

4. INTRODUCTION Audio mixers and consoles use three types of controls: Selectorswitches Knobs/Pots Faders. As the name suggests, selector switches simply allow you to select and direct audio sources into a specific audio channel

5. INTRODUCTION Faders (Volume Control) can either be rotatory in design or linear. Faders are also referred to as attenuates, Knobs/Pots(Potentiometer)-for gain controls. These are shown below.

6. Fundamentals of mixing Mixing is the stage at which all the sounds come together to be blended as one. Mixing involves making adjustments to eliminate masking conflicts. A great mix can be defined as having a perfect balance of the following:

7. FUNDAMENTALS OF MIXING

8. FUNDAMENTALS OF MIXING A great mix can be defined as having a perfect balance of the following: • Balance of Voices/Instruments(as to which should have priority) • Balance of Tone(bright, deep and full; or dull, empty and plain)

9. FUNDAMENTALS OF MIXING • Balance of Space i.e Stereo Field is full and distinct `.This can be achieved using panning • Balance of Interest-simply means having several elements that make the mix exciting using effects, processors and equalization 

10. FUNDAMENTALS OF MIXING This is done by : • Muting offending channels • Lowering the level of certain channels to let others have priority • Using equalization • Metering/Monitoring-Using Your Meters,Speakers /Headphones

11. Gain & Level SeTTINGS Gain-The power of the raw incoming audio signal into a mixer. Gain and levels refer to the loudness of the audio. Gain is the input level of the clips and volume is the output. The volume is adjusted using the channel strip faders in respect to the gain to achieve 0dB.

12. NOW LETS WATCH AN INSTRUCTIONAL VIDEO ON HOW TO SET GAIN ON A MIXER

13. LEVEL CONTROL & mixing Audio mixing goes beyond just watching a VU meter. The total subjective effect as heard through the speakers or earphones should be used to evaluate the final mix.

14. LEVELs and CONTROL The issue of levels brings up all sorts of questions, mainly: What level should I aim for? When working with normal speech, a great target level is -15 or -12 dBFS (use whichever is marked on your meter). If you have a loudness meter, aim for -24 LUFS.

15. HEADPHONES • Head Phone-Wearing headphones, helps to hear the problems you need to prevent.

16. MIXING PROBLEMS • Inconsistent levels • Abrupt entrances/exits to clips • Abrupt changes in background sound • Bright- or muddy-sounding audio • Phase issues • Overly compressed (or limited) audio • Stereo balance issues

17. introduction to equalisation • In most literal sense, equalisation means “to make equal.” But make what equal? • Equalizers are used in recording studio, radio studio, production control rooms and live sound reinforcement and in instrument amplifiers to correct or adjust the response of microphones, loudspeakers and hall acoustics. Equalization may also be used to eliminate or reduce unwanted sounds

18. What is equalisation? The term equalizer (EQ) has its origins in early telephone engineering, when high frequency losses over long distances had to be corrected so that the spectrum of the sound at the receiver matched the sound spectrum that was initially transmitted. Since then, the term has been used for any procedure that involves altering or adjusting the magnitude frequency response. An Equaliser separates a signal into separate frequency bands to allow for individual volume adjustments of each band

19. What is equalisation? • Equalization is the process of adjusting the balance between frequency components with an electronic signal. • The circuit or equipment used to achieve equalization is called an EQUALIZER. • These devices strengthen (boost) or weaken (cut) the energy of specific frequency band or frequency ranges.

20. What does eq do? Equalisation is useful for making both corrective and creative changes to a sound, but it needs to be used with care. Corrective applications include making tonal changes to compensate for imperfect room acoustics, budget microphones or inaccurate loudspeaker systems. PA situation, excessive EQ boost in any part of the audio spectrum will increase the risk of acoustic feedback via the vocal microphones.

21. what does eq do? • .EQ helps your audio to sound better and correct problems when recording. You can even use it to create special effects. • The frequency range that people can hear is approximately from 20HZ to 20KHZ. An average person can hear most of this range, but usually not the extremes. Normally, 40HZ is the low and 16KZ the high end of a healthy human ear. • Most microphones take advantage of this by having frequency response of 20HZ to 20 KHZ.

22. Audio spectrum(frequency band) The audio spectrum is the audible frequency range at which humans can hear. The audio spectrum range spans from 20 Hz to 20,000 Hz and can be effectively broken down into seven different frequency bands, with each having a different impact on the total sound.

23. Audio spectrum(frequency band) The seven frequency bands are: • Sub-bass • Bass • Low midrange • Midrange • Upper midrange • Presence • Brilliance

24. Frequency band

25. Frequency band

26. Common types equalisation Shelving EQ – all frequencies above and below a certain point are boosted or attenuated the same amount. This creates a “shelf” in the frequency spectrum. Bell EQ - boost or attenuate a range of frequencies centred around a certain point. The specified point is affected the most, frequencies further from the point are affected less.

27. Common types equalisation Parametric EQ – uses bell equalization, usually with knobs for different frequencies, but have the significant advantage of being adjusted. Graphic EQ – provide a very intuitive way to work-separate slider controls. For different frequencies are laid out in a way which represent the frequency spectrum. Each slider adjusts one frequency band.

28. PARAMETRIC equaliser This is the most powerful and flexible of the equalizer types. Midrange bands in a parametric equalizer have three adjustments: gain, center frequency, and quality factor Q(or bandwidth). A parametric equalizer allows the operator to add a peak or a notch at an arbitrary location in the audio spectrum.

29. Parametric Equaliser This is the most powerful and flexible of the equalizer types. Midrange bands in a parametric equalizer have three adjustments: gain, center frequency, and quality factor Q(or bandwidth). A parametric equalizer allows the operator to add a peak or a notch at an arbitrary location in the audio spectrum.

30. Parametric Equaliser

31. Parametric Equaliser

32. Parametric Equaliser

33. GRAPHIC Equaliser • Graphic Equalisers work by splitting the sound spectrum • into narrow, adjacent frequency bands and giving each • band its own cut/boost slider. The term Graphic comes • about because the position or ÔcurveÕ of the sliders gives a • graphic representation of the way in which the settings • affect the audio frequency range.

34. GRAPHIC Equaliser

35. equalization High freq. control High-mid with selectable frequency range Low-mid with selectable frequency range Low frequency control

36. equalization

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