Parametric Audio Equalizer for Android Devices

This example shows how to use the Single-Band Parametric EQ block and the multibandParametricEQ System object™ from the Audio Toolbox™ to implement a parametric audio equalizer model. You can run the model on your host computer or deploy it to an Android device.

Introduction

Parametric equalizers are used to adjust the frequency response of audio systems. For example, a parametric equalizer can compensate for biases introduced by specific speakers. Equalization is a primary tool in audio recording technologies.

In this example, you design a parametric audio equalizer in a Simulink® model. You can run your model on the host computer or an Android device. The equalization algorithm is a cascade of three filters with tunable center frequencies, bandwidths, and gains. You can visualize the frequency response in real time while adjusting the parameters.

Required Hardware

To run this example on Android devices you need the following hardware:

• Android phone or tablet

• USB cable to connect the device to your development (host) computer

Model Setup

The audioEqualizerAndroid model provides a choice of device (host computer or Android device), and audio source (MATLAB workspace or microphone). You can choose the configuration by clicking the Configuration UI button.

Configuration UI:

Run Model on the Host Computer

When you choose to run the model on the host computer, a UI designed to interact with the simulation is provided and can be opened by clicking Host Tuning UI.

Host Tuning UI:

The UI allows you to tune the parameters of three filters individually, and view the frequency response in real time. You can also check the Bypass check box to compare the modified sound with the original sound.

Click the View Frequency Response button to visualize the frequency response of the filters.

Run Model on an Android Device

To run the model on your Android device, you need to first ensure that you have installed Simulink Support Package for Android Devices and that your Android device is provisioned.

Once your Android device is properly configured, use a USB cable to connect the device to your host computer.

You can choose to make a standalone Android equalizer app by clicking the Deploy to hardware button on the Simulink Editor toolbar. After deployment, the app can run on your Android device even when it is disconnected from the host computer. The parameter tuning UI and the frequency response display on your Android device screen, as shown below: