Hi Tanu, Am 29.02.2016 um 15:13 schrieb Tanu Kaskinen: > On Mon, 2016-02-29 at 14:23 +0100, Klaus Jaensch wrote: >> Hello, >> >> we use USB audio devices (e.g. M-Audio Fast Track and Focusrite Scarlett >> 2i2) to record mono speech on Ubuntu. >> We face the problem that for mono recordings both input channels of the >> devices are mixed together. But we want to record only the left channel, >> not the mix. The left channel gets only half of the dynamic range; the >> signal amplitude does not exceed -6dB. >> >> Is there a way to configure PulseAudio accordingly? > If the recording program allows, you can specify its channel map to be > "left" instead of "mono". For example, parecord supports the --channel- > map option. > > If the recording program forces you to use "mono" channel map, you can > use module-remap-source: > > pactl load-module module-remap-source sink_name=mono_source master=... channel_map=mono master_channel_map=left remix=no > > The "master" argument is the source name of the usb sound card. You can > find the name with "pactl list sources". Once the remap source is > loaded, you can point the recording program to "mono_source". thanks, that works fine! I need it system-wide for all users, therefore I put these lines: load-module module-remap-source source_name=mono_source master=alsa_input.usb-M-Audio_Fast_Track-00-Track.iec958-stereo channel_map=mono master_channel_map=left remix=no set-default-source mono_source to /etc/pulse/default.pa I'm wondering why it is the default to mix the channels. I think mixing should be done by the applications, not by the audio system. Klaus > -- > Tanu -- ------------------------------------------ Klaus Jaensch Muenchen Germany Institut fuer Phonetik und Sprachverarbeitung Schellingstr.3/II Room 223 VG 80799 München Phone (Work): +49-(0)89-2180-2806 Fax: +49-(0)89-2180-5790 EMail: klausj at phonetik.uni-muenchen.de
