Archive for June, 2010

If you, like me, like to watch the world cup in South Africa but hate the monotonous sound of the so called Vuvuzelas this post is for you.

I will show you how to filter out the noise using your Fedora machine:

First we need to install the necessary tools and add ourselves to the jackuser group:

yum install jack-rack qjackctl pulseaudio-module-jack ladspa-swh-plugins
gpasswd -a felix jackuser

Of course these commands need to be run as root and you need to replace felix with your username. After you’re done with that you need to log off for the changes to become effective.

Now launch QJackctl from the Applications menu and start configuring it. The following screenshots show my settings. The don’t necessarily need to be your settings, so this is a little bit trial and error.

After you changed the settings you can start the Jack daemon by pressing “Start” in the QJackctl window.

Now you fire up Jack-Rack from the Applications Menu as well. For anything to happen with your audio within Jack-Rack you need to connect your audio devices to the Jack connection of Jack-Rack. This can be done using QJackctl. See below screenshot on how I connected Jack-Rack with my sound devices:

And finally you need to add the filters to Jack-Rack. I used a serial setup of four “Mag’s Notch Filter”. You can add them by clicking on the “+” button at the top left of the Jack-Rack window. Then go to Frequency -> Filters -> Notch -> Mag’s Notch Filter.

Here’s a screenshot of my filter settings:

Frequencies are 233, 466, 932 and 1864 Hz.

Kudos for the information on frequencies go to Surfpoeten.de.

Now you need to hook up the sound output of your TV or cable/sattelite receiver to your computer’s audio input and in turn connect your computer’s audio output to some speakers or headphones.

I usually leave both filters at the end of the rack disabled as that allows for more atmosphere while keeping the vuvuzelas down

It’s not perfect but seems to work okay. If you manage to tweak your setup to achive a better sound feel free to add your findings to the comments.

And now enjoy the next world cup game without those annoying vuvuzelas

Edit

Here’s a command line for mplayer to achieve the same within mplayer:

mplayer -af pan=1:0.5:0.5,sinesuppress=233:0.01,sinesuppress=466:0.01,sinesuppress=932:0.01,sinesuppress=1864:0.01,sinesuppress=232:0.01,sinesuppress=465:0.01,sinesuppress=931:0.01,sinesuppress=1863:0.01,sinesuppress=234:0.01,sinesuppress=467:0.01,sinesuppress=933:0.01,sinesuppress=1865:0.01

Found by Thomas Moschny at http://pastebin.com/KunkS0uk