Equalisers
•Download as PPTX, PDF•
2 likes•3,173 views
Frequency Harmonics Types of EQ; Shelving, Filters, Parametric, Graphic, Q Factor Typical Mixing Desk EQ Typical Software EQ Application
Recommended
More Related Content
What's hot
What's hot (20)
Viewers also liked
Viewers also liked (20)
Similar to Equalisers
Similar to Equalisers (20)
More from Magic Finger Lounge
More from Magic Finger Lounge (9)
Recently uploaded
Recently uploaded (20)
Equalisers
- 1. Equalizers An Introduction to EQ, Types & Application stuart.jones3@southwales.ac.uk www.stuartjones.org
- 2. EQ 1. Introduction 2. Frequency 3. Harmonics 4. Types of EQ: a. Shelving EQ b. Filters c. Parametric EQ d. Graphic EQ 5. Q Factor Typical Mixing Desk EQ 6. Typical Software EQ 7. Application 8. Supporting Documents Agenda
- 4. EQ What is EQ? Control of the amplitude of areas of frequencies.
- 5. Why is it called E.Q.? Early telephone systems used EQ to balance or equalise input with output to compensate for deterioration within long cables. EQ Nowadays EQ gets used for more creative purposes such as filter sweeps.
- 6. EQ Frequency
- 7. EQ Frequency Time Amplitude 0 + - t The rate at which the source oscillates is the frequency of the sound wave it produces, and is quoted in hertz (Hz) or cycles per second (cps). 1000 hertz is termed 1 kilohertz (1kHz)
- 8. EQ The lowest string of a guitar vibrates approximately 82 times per seconds. This means that a low ‘E’ (E2) on a acoustic guitar has a frequency of 82 Hertz. A standard bass is an octave below at 41.2Hz (E1) Frequency
- 9. EQ The lowest note on a standard piano is 27.5 Hz, and the highest note is 4186 Hz. However, as all sound contain many frequency components. These are known as Harmonics. In the case of the piano, frequencies will extend above 4kHz. Frequency
- 10. EQ 3. Harmonics
- 11. EQ Harmonics In this example, the sound is toggled between a sine wave and a square wave each at 100Hz. The Sine wave is a simple waveform containing no harmonic content. However, the square wave is rich in harmonics and extends far beyond the fundamental frequency.
- 12. EQ Image showing a Square Wave with a fundamental frequency at 100Hz. The chart on the right shows its harmonic content Harmonic Frequency Amplitude f 100 1 1st 300 1/3 2nd 500 1/5 3rd 700 1/7 4th 900 1/9 Harmonics
- 13. EQ This example shows middle C on a piano. This has a fundamental frequency of 261.626 Hz and also contain components at 523Hz, 1046Hz, 2093Hz and so on. Harmonics
- 14. Types of EQ
- 15. EQ A - Shelving EQ
- 16. EQ Shelving EQ High Shelving Band (10 decibel (dB) boost applied at 1kHz)
- 17. EQ Shelving EQ Low Shelving Band (10 decibel (dB) boost applied at 1kHz)
- 18. EQ B - Filters
- 19. EQ Lowpass Filter (Showing 1kHz Cut @ 24dB/octave) Filters
- 20. EQ Highpass Filter (Showing 1kHz Cut @ 24dB/octave) High pass filters are usually found on mixing desks. Used to cut out unwanted rumble. Filters
- 21. EQ In this example, for every octave beyond the 10kHz cut off point, the signal is attenuated by 6dB
- 22. EQ Now the filter is set at 48dB/Oct the slope is much steeper
- 23. EQ C - Parametric EQ
- 24. EQ This has three controls: 1.cut/boost - dB 2.sweep control - Hz 3.‘Q’ factor - The ‘Q’ factor control adjusts the width of the band of frequencies to be attenuated. (how steeply it slopes). Parametric EQ
- 25. EQ Q Factor
- 26. EQ Q Factor 3dB f0f1 f2 frequency (Hz) Level(dB) Low Q
- 27. EQ 3dB f0f1 f2 frequency (Hz) Level(dB) High Q Q Factor
- 28. EQ Peaking band - wide bandwidth (low Q) Q Factor
- 29. EQ Peaking band - narrow bandwidth (high Q) Q Factor
- 30. EQ D - Graphic
- 31. EQ A series of fixed bands that can boost or cut. However, frequency bands cannot be moved. The more bands the better. Professional graphics have 31/32 bands and are stereo. Some uses for graphic EQ: • Mastering – When mastering a final mix. • Live – Different venues have different acoustics. You could use a graphic Eq for the front of house sound or the on stage monitor mix if your lucky enough to have two EQs. • More flexible. Graphic
- 32. Typical Mixing Desk EQ
- 33. Audient ASP8024 EQ 1 2 3 4 HF Shelving EQ - 2 band boost/cut for high and low frequencies. Switchable between 10kHz and 18kHz. LF Shelving EQ - 2 band boost/cut for high and low frequencies. Switchable between 50Hz and 100Hz. Places the eq in circuit 5 6 Parametric EQ - Boost/Cut (dB) 1 3 5 4 2 6 6 Parametric EQ - Sweep (kHz) Parametric EQ - Q Factor 7 Places the eq in the short fader path (before tape)
- 35. EQ Logic Pro Channel EQ 1 12 23 3 3 3 1 2 3 Shelving EQ Filter EQ Parametric EQ 4 4 Q Factor
- 36. EQ Application
- 37. EQ Source - http://www.offbeat.co.uk/wp-content/uploads/2012/06/eq-chart.pdf These types of EQ charts are common place and act as a good introduction to instrument frequencies.
- 38. EQ 1. Switch out the equaliser. 2. Listen to the raw sound. 3. Imagine the perfect sound. 4. Dual in an EQ setting that you hope will match your imagination. 5. Put the EQ in. 6. Not the right sound? See 1 EQ Tips
- 39. EQ The human ear is great at comparing between toggled states (A:B). It is not so good at following slow changes because it quickly adapts and loses perspective. Why?
- 40. EQ Web • http://www.stuartjones.org.uk/Student_Resources/Studio_Tutorials/Entries/2010/7/4_AUDIENT_ASP8024_- _Equaliser.html • http://www.wikirecording.org/EQ • http://www.independentrecording.net/irn/resources/freqchart/main_display.htm • http://www.offbeat.co.uk/wp-content/uploads/2012/06/eq-chart.pdf • http://www.rs-met.com/documents/tutorials/FrequencyAndPitch.pdf • The Mix Engineers Handbook - Bobby Owsinski Supporting Material • http://quiztones.net/ - Free ear training app Books • Creative_Sequencing_Techniques_for_Music_Production_(by Andrea Pejrolo) References
- 41. Equalizers An Introduction to EQ, Types & Application stuart.jones3@southwales.ac.uk www.stuartjones.org
Editor's Notes
- The rate at which the source oscillates is the frequency of the sound wave it produces, and is quoted in hertz (Hz) or cycles per second (cps). 1000 hertz is termed 1 kilohertz (1kHz)
- In this example, the sound is toggled between a sine wave and a square wave each at 100Hz. The Sine wave is a simple waveform containing no harmonic content. However, the square wave is rich in harmonics and extends far beyond the fundamental frequency.
- Amplitude - Amplitude in a very general sense is just the maximum displacement of an oscillation.
- Shelving-type equalizers increase or attenuate the level of a wide range of frequencies by a fixed amount. A high shelf affects the level of high frequencies, while below a certain point, the low frequencies are unaffected.
- A low shelf will affect low frequencies up to a certain point and then above that point will have little effect.
- A pass filter attenuates either high or low frequencies while allowing other frequencies to pass unfiltered. A high-pass filter modifies a signal only by taking out low frequencies; a low-pass filter only modifies the audio signal by taking out high frequencies. A pass filter is described by its cut-off point and slope. The cut-off point is the frequency where high or low-frequencies will be removed. The slope, given in decibels per octave, describes a ratio of how the filter attenuates frequencies past the cut-off point (e.g. 12 dB per octave). A band-pass filter is a combination (in series) of one high-pass filter and one low-pass filter which together allow only a band of frequencies to pass, attenuating both high and low frequencies past certain cut-off points.
- Very useful for cleaning up audio - removing unwanted low end/ Air con etc.
- One common type of equalizer is the graphic equalizer which consists of a bank of sliders for boosting and cutting different bands (or frequency ranges) of sound. The number and width of filters depends on application. A simple car audio equalizer might have one bank of filters controlling two channels for easy adjustment of stereo sound, and contain five to ten filter bands. A typical equalizer for professional live sound reinforcement has some 25 to 31 bands, necessary for quick control of feedback tones and room modes. Such an equalizer is called a 1/3-octave equalizer (spoken informally as "third-octave EQ") because the center frequency of each filter is spaced one third of an octave away from its neighbors, three filters to an octave. Equalizers with half as many filters per octave are common where less precise general tone-shaping is desired—this design is called a 2/3-octave equalizer.