Transcript Electric Guitar

SYED SYAHRIL
TRADITIONAL MUSICAL INSTRUMENT SIMULATOR FOR GUITAR
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OVERVIEW
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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
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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
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OBJECTIVE
• Develop a program that simulates a traditional
musical instrument (Kecapi) by using an easily
accessible instrument (Electric Guitar)
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TRADITIONAL MUSICAL INSTRUMENT SIMULATOR FOR GUITAR
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TOOLS - Guitar
• One of the most common music instrument
• String type which is suitable for string type
traditional ones
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TRADITIONAL MUSICAL INSTRUMENT SIMULATOR FOR GUITAR
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TOOLS - Kecapi
• Indonesian traditional music instrument
• Sound produced by the sound hole
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TRADITIONAL MUSICAL INSTRUMENT SIMULATOR FOR GUITAR
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Guitar vs Kecapi
Comparison on notes produced
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TRADITIONAL MUSICAL INSTRUMENT SIMULATOR FOR GUITAR
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TOOLS – Microphone
• 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
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TRADITIONAL MUSICAL INSTRUMENT SIMULATOR FOR GUITAR
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TOOLS – Microphone (Comparison)
Common
House
Microphone
Shure SM62
Shure SM57
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TRADITIONAL MUSICAL INSTRUMENT SIMULATOR FOR GUITAR
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TOOLS - Simulink
• MATLAB add-on
• Graphical environment in developing simulations
• Based on flow of signal trough various type of blocks
Running simulation
Simulink
Blockset
Signal flow lines
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TRADITIONAL MUSICAL INSTRUMENT SIMULATOR FOR GUITAR
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TOOLS - Simulink
Tools used in developing the model
name.wav
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Constant
-6900
z
To Wave
Device
DSP
1
Delay
-f
z
Out
Variable
Fractional Delay
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To Wave
File
FDATool
Gain
Sine Wave
Integer Delay1
In
Sum
Digital
Filter Design
From Wave File
speech_dft.wav
(22050Hz/1Ch/16b)
From Wave
File
TRADITIONAL MUSICAL INSTRUMENT SIMULATOR FOR GUITAR
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TOOLS – Wavelab 5
Audio recording & editing software used in
editing recorded kecapi sound
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TRADITIONAL MUSICAL INSTRUMENT SIMULATOR FOR GUITAR
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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
FDATool
Filter 1
1
In1
FDATool
1
Out1
Filter 2
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TRADITIONAL MUSICAL INSTRUMENT SIMULATOR FOR GUITAR
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DIGITAL AUDIO EFFECTS – Chorus 1
• Product of more than one source playing a same
sound in unison
• The imperfection of the combination causes
chorus effect
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TRADITIONAL MUSICAL INSTRUMENT SIMULATOR FOR GUITAR
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DIGITAL AUDIO EFFECTS – Chorus 2
Parameters in configuring a chorus effect :
• Sweep Depth
• Number of voices
• Delay
• Rate
Rate
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TRADITIONAL MUSICAL INSTRUMENT SIMULATOR FOR GUITAR
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DIGITAL AUDIO EFFECTS – Chorus 3
The number of voices is simply the number of
delayed signal added to the output
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TRADITIONAL MUSICAL INSTRUMENT SIMULATOR FOR GUITAR
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DIGITAL AUDIO EFFECTS - Reverberation
• 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
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TRADITIONAL MUSICAL INSTRUMENT SIMULATOR FOR GUITAR
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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
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TRADITIONAL MUSICAL INSTRUMENT SIMULATOR FOR GUITAR
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TARGET INSTRUMENT ANALYSIS 1
Time domain analysis
Kecapi and electric guitar plot in time domain
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amplitude kecapi
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amplitude guitar
•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
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TRADITIONAL MUSICAL INSTRUMENT SIMULATOR FOR GUITAR
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TARGET INSTRUMENT ANALYSIS 2
•Frequency domain
analysis
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dB (kecapi)
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frequency,Hz
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dB (guitar)
•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
Frequency Domain Plot
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40
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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
From Wave File
sample.wav
In1 Out1
In1 Out1
In1 Out1
4
Gain2
From Wave
File
Equalizer
Subsystem
chorus
subsystem
Reverberation
Subsystem
To Wave
Device
FDATool
3
sample.wav
Gain1
Bypass Filter
SYED SYAHRIL
TRADITIONAL MUSICAL INSTRUMENT SIMULATOR FOR GUITAR
To Wave
File
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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
FDATool
filter
1
Gain1
Low Pass
1
1
Out1
FDATool
In1
3
Gain
High Pass
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TRADITIONAL MUSICAL INSTRUMENT SIMULATOR FOR GUITAR
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SUBSYSTEM – Equalizer 2
• 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
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TRADITIONAL MUSICAL INSTRUMENT SIMULATOR FOR GUITAR
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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
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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 the
played string
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In1
Gain1
In
Delay
DSP
z
-f
Out
Variable
Fractional Delay
1
Gain
1
Out1
Sine Wave
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In
Delay
DSP
z
-f
Out
Variable
Fractional Delay1
1
Gain2
Sine Wave1
130
In
Delay z
DSP
-f
Out
Variable
Fractional Delay2
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Gain3
Sine Wave2
130
SYED SYAHRIL
TRADITIONAL MUSICAL INSTRUMENT SIMULATOR FOR GUITAR
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SUBSYSTEM – Chorus 2
• Sine wave generator used as a Low
frequency oscillator (LFO)
• Every voice has different amplitudes
and frequency (Rate)
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In1
Gain1
In
Delay
DSP
z
-f
Out
Variable
Fractional Delay
1
Gain
1
Out1
Sine Wave
130
In
Delay
DSP
z
-f
Out
Variable
Fractional Delay1
1
Gain2
Sine Wave1
130
Rate
In
Delay z
DSP
-f
Out
Variable
Fractional Delay2
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Gain3
Sine Wave2
130
SYED SYAHRIL
TRADITIONAL MUSICAL INSTRUMENT SIMULATOR FOR GUITAR
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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
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Feedback Gain
1
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-7700
z
Delay Mix
In1
Delay Mix3
Integer Delay
1
Out1
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Feedback Gain1
z
-6900
Integer Delay1
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Delay Mix1
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Feedback Gain2
-7100
z
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Delay Mix2
Integer Delay2
SYED SYAHRIL
TRADITIONAL MUSICAL INSTRUMENT SIMULATOR FOR GUITAR
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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
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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)
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Model Output
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COMPARISON – Frequency Domain
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Guitar
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dB (kecapi)
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frequency,Hz
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Model Output
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dB (guitar)
• 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
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TRADITIONAL MUSICAL INSTRUMENT SIMULATOR FOR GUITAR
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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
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TRADITIONAL MUSICAL INSTRUMENT SIMULATOR FOR GUITAR
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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
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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
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SYED SYAHRIL
TRADITIONAL MUSICAL INSTRUMENT SIMULATOR FOR GUITAR
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