[LAU] getting LFE channel to work with PulseAudio 5.1

David Kastrup dak at gnu.org
Sat Dec 2 09:12:22 UTC 2017


john gibby <johnalan.gibby-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org>
writes:

> Goodness, I'm so frustrated...
>
> Finally I managed to get the LFE channel to show up as a pulseaudio sink.
> Now I have all 6 (5.1) channels there, and last night I managed to get it
> all started and watch a movie, and it sounded good.  My Pianoteq didn't
> work (notes played from the app, but not from the actual keyboard), but I
> thought I would be able to figure that out soon.   But then I came home
> from work and now I'm stuck again.  Can't get anything to work!! I don't
> really know what I'm doing, so I spend hours trying different combinations,
> but I'm not getting anywhere.  Here are the pieces of my puzzle:
>
> 1. qjackctl and hdspmixer.  I know I have to run hdspmixer to get driver
> loaded for the RME 9652 card,

No?  The driver gets loaded by hdsploader.  hdspmixer sets mixer
defaults useful for hearing something, but you can do that
non-interactively using amixer.  I have a hdspreset script looking like

#!/bin/sh
amixer -c 1 cset "iface=CARD,name=Precise Pointer" 1
# Inputs to HDSP Mixer
# ========================================================================
# Multiface analogue inputs 1-8      = amixer source channels 0-7
# Multiface ADAT inputs 1-8          = amixer source channels 16-23
# Multiface SPDIF input              = amixer source channels 24-25
# alsa_pcm:playback_1-26             = amixer source channels 26-51
# 
# Outputs from HDSP Mixer
# ========================================================================
# Multiface analogue outputs 1-8     = amixer destination channels 0-7
# Multiface ADAT outputs 1-8         = amixer destination channels 16-23
# Multiface SPDIF output             = amixer destination channels 24-25
# Multiface line (headphone) output  = amixer destination channels 26-27
# 
# Mapping between Multiface inputs and alsa_pcm:capture channels
# ========================================================================
# Multiface analogue inputs 1-8      = capture_1-8
# Multiface ADAT inputs 1-8          = capture_9-16
# Multiface SPDIF input              = capture_17-18
amixer -c 1 cset numid=5 26,0,65535
amixer -c 1 cset numid=5 27,1,65535

That would appear to put through the playback outputs 1 and 2 to analog
outputs 1 and 2.

Don't ask me about the Precise Pointer thing: at some point of time
jackd and pulseaudio needed _different_ settings in order to work
properly.  Don't remember which was which or whether this is still the
case.

-- 
David Kastrup


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