[pulseaudio-discuss] New Module: module-lfe-lp

Justin Chudgar justin at justinzane.com
Mon Mar 18 17:24:52 PDT 2013

I've created a module to ensure that only low frequencies are sent to devices 
at the end of an "lfe"/"subwoofer" channel. This module allows the user to 
select the master channel, the low pass cutoff frequency (aka corner freq, -3dB 
freq) and the number of filter poles.

The motivation for this is that I have a 5.1 surround amp/speaker setup but 
listen primarly to stereo sources. With pulseaudio's default, my subwoofer is 
unused and enabling the naive remixing send full band (20Hz-20kHz) to the sub 
which sounds like mud. :( By using this module, i can always use all speakers 
with the frequencies they are capable of reproducing.

For those who primarily listen to Dolby, THX, etc. properly mastered surround 
movies or DVD-Audios, this is not advised.

[Please note that I am neither a skilled programmer or signal processing 
engineer, so target your suggestions and advice in way that I just might 
understand. Much of this module was based on the advice of all the great folks 
on #pulseaudio.]

The code is currently on github at


I am grateful for any criticisms or suggestions about this, and I would like 
to get this merged into mainline sometime. 


More information about the pulseaudio-discuss mailing list