Hello, I am trying to setup a lowpass filter for my subwoofer channel. I used the configuration template which is given in the ALSA wiki (http://alsa.opensrc.org/SurroundSound) as a template.
My asound.conf works when I use it like it is given below (sound from all speakers). But when I uncomment the second LADSPA plugin for the lowpass (plugin number 1), then I will only hear sound from the subwoofer (so only channel number 2 is processed lowpass_21to21). The other channels seem to be muted. I also tried the same setup which is given in the Wiki mentioned above, but this does not work at all (the delay_0.01s plugin is called delay_0,01s on my machine; it think it's because of the German locale; that's why I am using the ids for the LADSPA plugins now). I tried to set the policy of my first LADSPA plugin (number 0) to 'none', but this did not help. I was still hearing only the sound from the subwoofer. I tried to use 3 plugins for the 3 channels, each with policy none, but this did not work too. The ALSA documentation I found (e.g. http://www.alsa-project.org/alsa-doc/alsa-lib/pcm_plugins.html) is not very helpful at all (I am not sure how to set these bindings inside the plugins correctly). When I connect upmix_20to51 directly to upmix_21to51, the sound is working fine (of course without lowpass). I would greatly appreciate any hint about what I am doing wrong. Regards, Benjamin Eikel Package versions (I am using Debian unstable): libasound2 1.0.13-1 alsa-utils 1.0.13-1 alsa-base 1.0.13-2 My asound.conf: pcm.upmix_21to51 { type plug slave.pcm surround51 slave.channels 6 ttable { 0.0 1 # front left 1.1 1 # front right 0.2 1 # rear left 1.3 1 # rear right 0.4 0.5 # center 1.4 0.5 # center 2.5 1 # subwoofer } } pcm.upmix_20to51 { type plug slave.pcm lowpass_21to21 slave.channels 3 ttable { 0.0 1 # left channel 1.1 1 # right channel 0.2 0.5 # mix left and right ... 1.2 0.5 # ... channel for subwoofer } } pcm.lowpass_21to21 { type ladspa slave.pcm upmix_21to51 path "/usr/lib/ladspa" channels 3 plugins { 0 { id 1098 # Identity (Audio) (1098/identity_audio) policy duplicate input.bindings.0 "Input"; output.bindings.0 "Output"; } #1 { # id 1672 # 4 Pole Low-Pass Filter with Resonance (FCRCIA)(1672/lp4pole_fcrcia_oa) # policy none # input.bindings.2 "Input"; # output.bindings.2 "Output"; # input { # controls [ 300 0 ] # } #} } } ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys - and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ Alsa-user mailing list Alsa-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/alsa-user
