This document discusses concepts related to music technology including sound, pitch, frequency, harmonics, equalization (EQ), synthesis, oscillators, sound envelopes, and filters. It explains that sound is pressure disturbances propagating through a medium, usually air, while pitch is the repetition rate of a sound determined by its fundamental frequency. It describes how EQ is used to boost or cut certain frequencies to alter tonal qualities. Synthesis and sound design are also covered, noting how oscillators, envelopes, and filters can be used to manipulate raw waveforms and create customized sounds.

1. Music Technology
Musical Acoustics

2. What is Sound?

3. What is Sound?
Human Aspect of Sound?
Physical Aspect of Sound?

4. What is Sound?
Human Aspect of Sound?
What is heard
Physical Aspect of Sound?
Pressure disturbances propagating through a
medium, usually air

5. What is Pitch?

6. What is Pitch?
Repetition rate in a Sound
Not the same as frequency – a note with given
pitch normally contain many frequencies – what
are these different frequencies called?

7. What is Frequency?
Repetition rate for a simple oscillator
An oscillator is a repetitive wave e.g. sine wave,
saw wave etc.

8. What is Frequency measured in?

9. What is Frequency measured in?
Hertz
Normal hearing range is 30-15,000Hz

10. Frequencies
The range of pitch of the piano is 30-4,000Hz
The lowest notes are heard almost entirely via
the harmonics present in the tone.

11. Harmonics
All oscillations contain more than one
frequency. The cluster of all the different
sounding frequencies make the tone of the
sound.
The frequencies are often exact multiples of the
lowest, fundamental frequency, or near to this.

12. Harmonics

14. What, therefore, does EQ do?

15. What, therefore, does EQ do?
• Boosts and cuts certain frequencies, which will
inevitably, take out or increase the dynamic
volume of some of the harmonics.

16. EQ Bands
Normally three bands:
High Freq: 5-6kHz upwards
Mid-Range: 500Hz – 5kHz
Low Freq: 50Hz-500Hz

17. Why should you use EQ?

18. Why should you use EQ?
• Enhances the balance of the overall sound, by
altering the tonal qualities of individual
instruments
• Makes MIDI sounds more realistic
• Removes unwanted frequencies
• Separates mid-range sounds that are similar in
frequency, helps to give clarity to the mix, and
stops them blending too much on important parts
• Bring out important melodies

19. Types of EQ
Shelving EQ

20. Types of EQ
Shelving EQ:
High freq: Cut/boost all the signal above a
certain frequency
Low freq: Cut/boost all the signal below a
certain freq.
Can you draw it?

21. High-Shelf Boost
Low Shelf and High Shelf Cut

22. Band Pass EQ
Cut/boost the signal between an upper and
lower frequency.

23. Band Pass EQ
Cut/boost the signal between an upper and
lower frequency.

24. Sweep EQ
A band-pass EQ with the option of adjusting the
centre frequency around which the signal is
altered.
http://www.youtube.com/watch?v=Gmrve23xR
W8

25. Parametric EQ
A sweep EQ with the option of adjusting the ‘Q’
(also called resonance). This increases or
decreases the range over which the frequency is
cut or boosted either side of the centre
frequency (increases or decreases the
bandwidth)

26. • Low Q Factor:
wider bandwidth

27. • High Q Factor:
narrower
bandwidth

28. Why is this important?

29. Why is this important?
Important for ALL portfolio
Use music technology keywords in your logbook
to explain your choice of EQ and why.
Making sounds more realistic and fitting Task 1A
better.

30. Synthesis
What is Synthesis?
How have you currently been creating your
sounds for your instruments?

31. Synthesis
How are sounds created?

32. Synthesis
How are sounds created?
An oscillator creates a sound wave which can
then be manipulated to design the sound you
wish

33. Oscillators
Used to generate a raw repeating signal/wave
Different tyes of oscillators produce a variety of
signals including sine, triangle, sawtooth,
square and random noise waves

34. Sine Wave
• http://en.wikipedia.org/wiki/Sine_wave
• No harmonics

35. Triangle Wave
• http://en.wikipedia.org/wiki/Triangle_wave
• Only odd harmonics are sounded

36. Harmonic Numbers

37. Square Wave
http://en.wikipedia.org/wiki/Square_wave
Only uses odd harmonics – sounds similar to a
triangle wave but slightly brighter in treble

38. Sawtooth Waves
• http://en.wikipedia.org/wiki/Sawtooth_wave
• Uses all harmonics – sounds quite gritty

39. Why are these important to you?

40. Why are these important to you?
You can design your own sounds – very
important!!
Start with a template and then adjust it or start
from scratch if you wish!

41. What is the Sound Envelope?

42. What is the Sound Envelope?
ASDR
Attack
Sustain
Decay
Release
Alter the sound of the audio signal over time, from
the time it starts until the time there is no sound.

43. Sound Envelope
• What
about a
piano?

44. Sound Envelope (ASDR)
• Example of a piano: • What about
a trumpet?

45. Sound Envelope (ASDR)
How to design your sound using the sound
envelope
http://en.wikiaudio.org/ADSR_envelope

46. Filters
What do filters do?

47. Filters
What do filters do?
Modify a signal by cutting/removing a specific
frequency band. Changes the brightness of a
sound.
Filters use a cut-off frequency to define which
frequencies are removed from the signal
Two main types: high-pass and low-pass

48. Types of filters
Low pass filter – removes frequencies higher than the
cut-off frequency, allowing the lower frequencies to pass
through
High pass filter – removed frequencies lower than the
cut-off frequency, allowing the higher frequencies to pass
through.
Band pass filter – uses combination of both HPF and LPF
to allow only frequencies near the cut-off to pass through
Band-elimination filter – uses both LPF and HPF to
remove only frequencies near the cut off.
Peaking filter – emphasizes frequencies near the cut-off
frequency – also called resonance.

49. Sound Design and Synthesis
Start with an oscillator and work on the sound you
like
Adjust the envelope (ASDR)
Use EQ and filter to boost/cut the correct
harmonies
Use reverb to complete the sound
Write it all up in your logbook – so important to
show you can design your own sounds!!