> > > My laptop has built-in front left, front right, rear left, rear right and > > > subwoofer and something is strange. > > > When I set channel output to 5.1 or 4.1 and external speakers are > > > disconnected, then front left and front right work as expected but > > > > built-in > > > > > subwoofer is heard only if I test rear left channel (wrong channel > > > > mapping?) > > > ><a href="https://git.kernel.org/cgit/linux/kernel/git/tiwai/sound.git/commit/sound/pc"> https://git.kernel.org/cgit/linux/kernel/git/tiwai/sound.git/commit/sound/pc</a> > > i/hda/hda_codec.c?id=cd4035e814b04c009ece9939396d06370c53ed44 > > > > Seem only two pairs of stereo speakers and internal subwoofer at left > > channel before this patch > > > > ALSA: hda - Enable surround speakers (when line out is also present) > > On my laptop case "Virtual SurroundSound" is written . When I test front left > and rear left, I hear distinct sound, so it would mean it's from two different > sources of sound. The driver use more than two channels only after David 's patch But all internal speakers of the notebook are at front of the user, The 3D sound effect is quite different from your external 5.1 speakers Do you mean your 5930g need champ {FL FR RL RR LFE }? This can be easily implemented by using "swap center/lfe" switch for those codec support R/L swap <a href="http://git.alsa-project.org/?p=alsa-lib.git;a=blob_plain;f=test/chmap.c;hb=HEAD">http://git.alsa-project.org/?p=alsa-lib.git;a=blob_plain;f=test/chmap.c;hb=HEAD</a> <a href="http://git.alsa-project.org/?p=alsa-lib.git;a=tree;f=src/conf/pcm;hb=HEAD">http://git.alsa-project.org/?p=alsa-lib.git;a=tree;f=src/conf/pcm;hb=HEAD</a> If codec does not support R/L swap, your 4.1 swap chmap need 5.0 routing Do you expect pulseaudio show 4.1 swap(5.0) profile for internal speakers and 4.1 and 5.1 profiles for external speakers ?