Hi! For everyone interested in a solution to the problem below: Thanks to Benjamin Eikel, there is a great Howto in the ALSA wiki now. http://alsa.opensrc.org/Low-pass_filter_for_subwoofer_channel_(HOWTO) It only works with ALSA version 1.0.14rc2 (or probably above). Regards, Ingo Benjamin Eikel schrieb: >>> >>> 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 ] >>> # } >>> #} >>> } >>> } ------------------------------------------------------------------------- Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier. Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 _______________________________________________ Alsa-user mailing list Alsa-user@xxxxxxxxxxxxxxxxxxxxx https://lists.sourceforge.net/lists/listinfo/alsa-user
