Skip to content
master
Switch branches/tags
Code

Latest commit

 

Git stats

Files

Permalink
Failed to load latest commit information.
Type
Name
Latest commit message
Commit time
 
 
 
 
 
 

Digital IR measurements from Matlab

Use Jack to measure impulse responses from digital system directly from Matlab.

Installation

  1. Download & install Jack: http://jackaudio.org
  2. Put the provided function in a path where Matlab can find them

Setup

  1. Set up jackConfig (See digiIR.m for full example)
  2. Run startJack(configJack)
  3. Connect your application / system to Jack
  4. Run setupJack(configJack)

Usage

If the setup is complete, you may probe your system by simply running

[ y, t ] = recordImpulse( 1, recorder, jackConfig);

jackConfig

jackConfig is a struct that contains all necessary configuration variables:

jackConfig.jackpath = '/path/to/jack/'; % Default: /usr/local/bin/
jackConfig.App = 'APP'; % Default: Live
jackConfig.fs = 8000 - 192000; % Default: 44100
jackConfig.nBits = 4 - 32; % Default: 16
jackConfig.nChannels = 1 - 128; % Default: 2
jackConfig.framesize = 16 - 1024; % Default: 256
jackConfig.verbose = true/false; % Default: true
jackConfig.IDi = int; % Only after setupJack()
jackConfig.IDo = int; % Only after setupJack()

Probably stick to defaults for now.

Plotting

Several functions for convenient plotting are provided:

  • plotIR( y, t ) plots the IR y in the time domain.
  • plotSpectrogram( y, window, overlap, n, fs ) plots a spectrogram (frequency spectrum over time). The colormap is matplotlib's new default viridis.
  • plotFFT( y, fs ) plots the overall frequency spectrum.

They employ getSpectrogram( y, window, overlap, n, fs ) and easyFFT( y, fs ) respectively.

OSX only (for now)

Only tested on Mac OSX 10.10.5 with Jack 1.9.10 and Ableton Live. For non-OSX, maybe try adjusting the -d coreaudio backend driver in the startJack.m function.

Christoph Hohnerlein

mail@chrisclock.com, chohner@ccrma.stanford.edu

Nov 12, 2015

About

Small Matlab environment to measure digital Impulse Responses over Jack

Resources

Releases

No releases published

Packages

No packages published

Languages