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<br>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; Abstract  
 
<br>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; Abstract  
  
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<br>This document is investigating the effectiveness of a LPF, (low-pass-filter) when down-sampling. We are going to down-sample various types of audio signals with down-samplers which have different down-sampling rate.
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<br>This document is investigating the effectiveness of a LPF, (low-pass-filter) when down-sampling. We are going to down-sample various types of audio signals with down-samplers which have different down-sampling rate.  
  
 
<br>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;Introduction  
 
<br>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;Introduction  
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In this project, we are going to discuss how much the LPF will help in the audio signal down-sampling.  
 
In this project, we are going to discuss how much the LPF will help in the audio signal down-sampling.  
  
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<br>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;Procedures:<br>
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<br>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;Procedures:<br>  
  
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PART I.<br>In the first part of this project, we are going to develop the LPF effect to different down-sampling rates of 4, 8, and 16. In this project we are using FIR (finite impulse response) filter.<br>The audio signal we use is part of Waving Flag, the theme song of 2010 South Africa World Cup. We choose this signal because that this sound includes clear mix of human voice and sound of instruments.
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PART I.<br>In the first part of this project, we are going to develop the LPF effect to different down-sampling rates of 4, 8, and 16. In this project we are using FIR (finite impulse response) filter.<br>The audio signal we use is part of Waving Flag, the theme song of 2010 South Africa World Cup. We choose this signal because that this sound includes clear mix of human voice and sound of instruments.  
  
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The sound of original signal:&nbsp;<br>The DFT of original signal:  
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The sound of original signal:&nbsp;[https://projectrhea.org/rhea/images/f/f3/Flag.wav projectrhea.org/rhea/images/f/f3/Flag.wav]<br>The DFT of original signal:  
  
 
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Revision as of 23:48, 8 November 2011


Audio Signal Processing with Down-sampler and LPF Investigate


                                                                      Abstract


This document is investigating the effectiveness of a LPF, (low-pass-filter) when down-sampling. We are going to down-sample various types of audio signals with down-samplers which have different down-sampling rate.


                                                                     Introduction


Formally, down-sampling can be written as

        y[n]=x[Mn]

In the frequency domain, we will have

Dsamplef.png

The following figure could illustrate the reason of aliasing in down-sampling.

This Figure is done by Phil Schniter.

Dsample.png

In this project, we are going to discuss how much the LPF will help in the audio signal down-sampling.


                                                                         Procedures:

PART I.
In the first part of this project, we are going to develop the LPF effect to different down-sampling rates of 4, 8, and 16. In this project we are using FIR (finite impulse response) filter.
The audio signal we use is part of Waving Flag, the theme song of 2010 South Africa World Cup. We choose this signal because that this sound includes clear mix of human voice and sound of instruments.

The sound of original signal: projectrhea.org/rhea/images/f/f3/Flag.wav
The DFT of original signal:




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Abstract algebra continues the conceptual developments of linear algebra, on an even grander scale.

Dr. Paul Garrett