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SYED SYAHRIL TRADITIONAL MUSICAL INSTRUMENT SIMULATOR FOR GUITAR 1
SYED SYAHRIL TRADITIONAL MUSICAL INSTRUMENT SIMULATOR FOR GUITAR 2
OVERVIEW
• Motivations & Objectives• Development Tools• Digital Audio Effects• Target Traditional Instrument Analysis• Model Explanations• Results & Discussions• Conclusion & Recommendations
SYED SYAHRIL TRADITIONAL MUSICAL INSTRUMENT SIMULATOR FOR GUITAR 3
MOTIVATIONS
• Difficulties in obtaining most of traditional musical instruments
• Time consumption on learning new methods of playing traditional instruments
• Limitations of notes produced on certain traditional musical instruments
• Availabilities of western musical instruments simulators
SYED SYAHRIL TRADITIONAL MUSICAL INSTRUMENT SIMULATOR FOR GUITAR 4
OBJECTIVE
• Develop a program that simulates a traditional musical instrument (Kecapi) by using an easily accessible instrument (Electric Guitar)
SYED SYAHRIL TRADITIONAL MUSICAL INSTRUMENT SIMULATOR FOR GUITAR 5
• One of the most common music instrument• String type which is suitable for string type
traditional ones
TOOLS - Guitar
SYED SYAHRIL TRADITIONAL MUSICAL INSTRUMENT SIMULATOR FOR GUITAR 6
• Indonesian traditional music instrument• Sound produced by the sound hole
TOOLS - Kecapi
SYED SYAHRIL TRADITIONAL MUSICAL INSTRUMENT SIMULATOR FOR GUITAR 7
Guitar vs Kecapi
Comparison on notes produced
SYED SYAHRIL TRADITIONAL MUSICAL INSTRUMENT SIMULATOR FOR GUITAR 8
• Transducer – Air pressure to electrical signals• Used in recording Kecapi sound• Microphone are selected based on :
– Frequency response– Frequency range
• Shure SM57 are selected due to its balance on both specifications stated above as well as the cost
TOOLS – Microphone
SYED SYAHRIL TRADITIONAL MUSICAL INSTRUMENT SIMULATOR FOR GUITAR 9
TOOLS – Microphone (Comparison)Common House Microphone
Shure SM62
Shure SM57
SYED SYAHRIL TRADITIONAL MUSICAL INSTRUMENT SIMULATOR FOR GUITAR 10
TOOLS - Simulink• MATLAB add-on• Graphical environment in developing simulations• Based on flow of signal trough various type of blocks
Signal flow lines
Simulink BlocksetRunning simulation
SYED SYAHRIL TRADITIONAL MUSICAL INSTRUMENT SIMULATOR FOR GUITAR 11
TOOLS - Simulink
From Wave Filespeech_dft.wav
(22050Hz/1Ch/16b)
From WaveFile
z-f
In
DelayOut
VariableFractional Delay
Constant
130
DSP
Sine Wave
name.wav
To WaveFile
To WaveDevice
FDATool
DigitalFilter Design
z-6900
Integer Delay1
1
Gain
Sum
Tools used in developing the model
SYED SYAHRIL TRADITIONAL MUSICAL INSTRUMENT SIMULATOR FOR GUITAR 12
TOOLS – Wavelab 5
Audio recording & editing software used in editing recorded kecapi sound
SYED SYAHRIL TRADITIONAL MUSICAL INSTRUMENT SIMULATOR FOR GUITAR 13
DIGITAL AUDIO EFFECTS - Equalizer• Equalization (EQ) is the process of boosting or
cutting certain frequency components of a signal. • By applying some filters, audio signal of the
source will be equalized to a desired output
1
Out1FDATool
Filter 2
FDATool
Filter 11
In1
SYED SYAHRIL TRADITIONAL MUSICAL INSTRUMENT SIMULATOR FOR GUITAR 14
• Product of more than one source playing a same sound in unison
• The imperfection of the combination causes chorus effect
DIGITAL AUDIO EFFECTS – Chorus 1
SYED SYAHRIL TRADITIONAL MUSICAL INSTRUMENT SIMULATOR FOR GUITAR 15
Parameters in configuring a chorus effect :• Sweep Depth• Number of voices• Delay• Rate
DIGITAL AUDIO EFFECTS – Chorus 2
Rate
SYED SYAHRIL TRADITIONAL MUSICAL INSTRUMENT SIMULATOR FOR GUITAR 16
The number of voices is simply the number of delayed signal added to the output
DIGITAL AUDIO EFFECTS – Chorus 3
SYED SYAHRIL TRADITIONAL MUSICAL INSTRUMENT SIMULATOR FOR GUITAR 17
• Reverberation is the result of the many reflections of a sound that occurs in a room
• Reflected sound is a minimally delayed signal of the source
• Reverberation also occur in a sound box of an instrument
DIGITAL AUDIO EFFECTS - Reverberation
SYED SYAHRIL TRADITIONAL MUSICAL INSTRUMENT SIMULATOR FOR GUITAR 18
MODELING PROCESS
Two main parts :• Analyzing target instrument (Kecapi)
– Time domain– Frequency domain– Auditory
• Synthesizing the effect model (Simulink)– Applying analysis results– Configuring Simulink block parameters
SYED SYAHRIL TRADITIONAL MUSICAL INSTRUMENT SIMULATOR FOR GUITAR 19
TARGET INSTRUMENT ANALYSIS 1Time domain analysis
•Envelope fluctuates in kecapi
•Chorus effect are suggested to occur
•Similar string notes resonates each other
•Trough listening, the ‘watery’ sound normally caused by a chorus effect
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1-1
-0.5
0
0.5
1
seconds,time
am
plit
ude k
ecapi
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1-0.6
-0.4
-0.2
0
0.2
0.4
0.6
0.8
seconds,time
am
plit
ude g
uitar
Kecapi and electric guitar plot in time domain
SYED SYAHRIL TRADITIONAL MUSICAL INSTRUMENT SIMULATOR FOR GUITAR 20
TARGET INSTRUMENT ANALYSIS 2
0 1000 2000 3000 4000 5000 6000 7000 80000
20
40
60
80
100
frequency,Hz
dB (
keca
pi)
0 1000 2000 3000 4000 5000 6000 7000 80000
20
40
60
80
100
frequency,Hz
dB (
guita
r)
Frequency Domain Plot •Frequency domain analysis
•Kecapi contains more high frequency components
•Fundamental frequency of the note is lower in amplitude in a guitar
•A combination of filters is needed in order to equalize the electric guitar frequencies
SYED SYAHRIL TRADITIONAL MUSICAL INSTRUMENT SIMULATOR FOR GUITAR 21
MAIN MODEL• Simulation model developed based on analysis• Human auditory system is most important tool in the overall design of
the model• Main components : Equalizer, Chorus & Reverberation• Additional gain used to increase the volume of the manipulated signals
In1Out1
chorussubsystem
sample.wav
To WaveFile
To WaveDevice
In1Out1
ReverberationSubsystem
4
Gain2
3
Gain1
From Wave Filesample.wav
From WaveFile
In1Out1
EqualizerSubsystem
FDATool
Bypass Filter
SYED SYAHRIL TRADITIONAL MUSICAL INSTRUMENT SIMULATOR FOR GUITAR 22
SUBSYSTEM – Equalizer 1• Why ? To equalize the electric guitar frequency components to a
kecapi• Where ? Earlier part of the model to replicate the source (strings)• How ? A low-pass
and a high-pass filter
1
Out1
FDATool
Low Pass
FDATool
High Pass
1
Gain1
3
Gain
1
In1
SYED SYAHRIL TRADITIONAL MUSICAL INSTRUMENT SIMULATOR FOR GUITAR 23
• Low-pass filter with a cut off frequency of 2kHz
• Actually a band pass filter with a band pass frequency of 10Hz to 90Hz
• Not able to get a flat response for these values
SUBSYSTEM – Equalizer 2
SYED SYAHRIL TRADITIONAL MUSICAL INSTRUMENT SIMULATOR FOR GUITAR 24
SUBSYSTEM – Bypass Filter• How? - High-pass filter with cut off frequency of 2kHz• Where ? - Certain frequency components of the signal will bypass
the chorus subsystem• Why? - Higher frequency notes has slight chorus effect• Thinner strings which produces high frequency sound has less
effects on thicker strings of the same note (resonance)
SYED SYAHRIL TRADITIONAL MUSICAL INSTRUMENT SIMULATOR FOR GUITAR 25
SUBSYSTEM – Chorus 1• How? – three variably delayed signals (voice) with different delay
variables (chorus parameters)• Where? – After filters equalized the signal• Why? – Similar note strings
resonates each other• Voice gain values determines
its volume• Three voice chorus selected
since there is three similar string notes excluding theplayed string
1
Out1
z-f
In
DelayOut
VariableFractional Delay2
z-f
In
DelayOut
VariableFractional Delay1
z-f
In
DelayOut
VariableFractional Delay
DSP
Sine Wave2
DSP
Sine Wave1
DSP
Sine Wave
.6
Gain3
1
Gain2
.7
Gain1
1
Gain
130
130
130
1
In1
SYED SYAHRIL TRADITIONAL MUSICAL INSTRUMENT SIMULATOR FOR GUITAR 26
SUBSYSTEM – Chorus 2
1
Out1
z-f
In
DelayOut
VariableFractional Delay2
z-f
In
DelayOut
VariableFractional Delay1
z-f
In
DelayOut
VariableFractional Delay
DSP
Sine Wave2
DSP
Sine Wave1
DSP
Sine Wave
.6
Gain3
1
Gain2
.7
Gain1
1
Gain
130
130
130
1
In1
Rate
• Sine wave generator used as a Low frequency oscillator (LFO)
• Every voice has different amplitudes and frequency (Rate)
SYED SYAHRIL TRADITIONAL MUSICAL INSTRUMENT SIMULATOR FOR GUITAR 27
SUBSYSTEM - Reverberation• How? – constantly delayed signal added to the original signal• Where? – final part of the model• Why? – Reflections of the sound wave in the sound hole of the
kecapi• Number of voices are
are three due to the same reason as chorus
1
Out1
z-7100
Integer Delay2
z-6900
Integer Delay1
z-7700
Integer Delay
.5
Feedback Gain2
.6
Feedback Gain1
.6
Feedback Gain
.7
Delay Mix3
.5
Delay Mix2
.5
Delay Mix1
.4
Delay Mix1
In1
SYED SYAHRIL TRADITIONAL MUSICAL INSTRUMENT SIMULATOR FOR GUITAR 28
RESULTS & DISCUSSIONS
• The system is able to fairly produce the desired results
• Hearing the resultant audio sound is the best way of concluding the results
• Frequency & time domain plot comparison also referred as a benchmark for the results
SYED SYAHRIL TRADITIONAL MUSICAL INSTRUMENT SIMULATOR FOR GUITAR 29
COMPARISON – Time Domain• Envelope fluctuations are visible but not as smooth as the original
kecapi sound• Kecapi produces chorus and reverberation effects naturally (wood,
hollow body design). Where the system developed relies on digital signal processing
• Enhance filters, chorus & reverb parameters.• Use 24-bit in processing audio (high resolution, less quantization error)
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1-0.6
-0.4
-0.2
0
0.2
0.4
0.6
0.8
seconds,time
ampl
itude
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1-0.8
-0.6
-0.4
-0.2
0
0.2
0.4
0.6
seconds,time
ampl
itude
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1-0.8
-0.6
-0.4
-0.2
0
0.2
0.4
0.6
0.8
seconds,time
ampl
itude
Guitar Model Output Kecapi
SYED SYAHRIL TRADITIONAL MUSICAL INSTRUMENT SIMULATOR FOR GUITAR 30
COMPARISON – Frequency Domain• Model output shows
significant gain in higher frequencies of the guitar signal
• Noise introduced in the output
• The use of compressor in recording a guitar signal reduce the gain amount needed in the higher frequencies
0 1000 2000 3000 4000 5000 6000 7000 80000
10
20
30
40
50
60
70
80
90
100
frequency,HzdB
(guitar)
0 1000 2000 3000 4000 5000 6000 7000 80000
10
20
30
40
50
60
70
80
90
100
frequency,Hz
dB
(guitar)
0 1000 2000 3000 4000 5000 6000 7000 80000
10
20
30
40
50
60
70
80
90
100
frequency,Hz
dB
(kecapi)
Guitar
Model Output
Kecapi
SYED SYAHRIL TRADITIONAL MUSICAL INSTRUMENT SIMULATOR FOR GUITAR 31
COMPARISON – Real Audio
• Compares the sound of 3 sources of sound; electric guitar, kecapi as well as model output
• Sample of a similar single note by each source• Sample of a short music produce by these
sources
SYED SYAHRIL TRADITIONAL MUSICAL INSTRUMENT SIMULATOR FOR GUITAR 32
CONCLUSIONS
• In conclusion, the objectives stated in this project has been achieved by referring to the results obtained
• The usage of effects included in the model gives a good result but has plenty of room to improvise mainly in terms of its parameters and tools used
• With this achievement, traditional music may be easily produced and creatively expands a traditional musical instrument usage
SYED SYAHRIL TRADITIONAL MUSICAL INSTRUMENT SIMULATOR FOR GUITAR 33
RECOMMENDATIONS
• Further develop a model to simulate other traditional instruments especially string instruments
• Compile as a stand alone program rather than running it in Simulink
• Realize certain amount of traditional instruments simulation onto a DSP board
• Improve tools quality to produce better results
SYED SYAHRIL TRADITIONAL MUSICAL INSTRUMENT SIMULATOR FOR GUITAR 34