Arch Linux

evert_

Member

Registered: 2007-07-27

Posts: 30

5.1 Audio with 3 jacks: How to config this ?

Good evening everybody,

I'm having since short a 5.1audio set, a logitech x540. I love this set, not too priced for a 5.1set. I'm coming from some crappy cheap trust 2.1set, so this is a big improvement.

But now the problem: my set needs to be connected to my motherboard with those '3 jack cables', because it's not having a coax cable. (normal for a budget set). But my motherboard has got only those 3 'normal' jacks. But not a big problem, i found the following in my motherboard guide:

Light Blue : Surround
Lime    : Front Speaker Out
Pink : Center/bass

So hardware seen it isn't a problem to use those jacks . So i connected them like told in my motherboard manual. But now i don't get them working under linux. I don't know how to config it. I'm having the following audio card:

00:10.1 Audio device: nVidia Corporation MCP51 High Definition Audio (rev a2)

I'm using alsa, so i've searched in alsamixer, but i didn't find anything usefull there. Anybody who can help me with this pls ?

evert_

Member

Registered: 2007-07-27

Posts: 30

Re: 5.1 Audio with 3 jacks: How to config this ?

sorry for the little bump

tom5760

Member

From: Philadelphia, PA, USA

Registered: 2006-02-05

Posts: 283

Website

Re: 5.1 Audio with 3 jacks: How to config this ?

I have a set up very very similar to you.  For me, there is a switch in alsamixer that says something like "2ch"  (2 channels).  If I hit up on that switch it changes to "4ch" and then to "6ch", which is what I have it set to now.  Then, I also have a "Duplicate Front" control, which I unmuted.  Everything seems to be fine.  Do you have these controls in your alsamixer?

evert_

Member

Registered: 2007-07-27

Posts: 30

Re: 5.1 Audio with 3 jacks: How to config this ?

Nope, I'm not having that '2ch/4ch/6ch' switch in my alsamixer.

tom5760

Member

From: Philadelphia, PA, USA

Registered: 2006-02-05

Posts: 283

Website

Re: 5.1 Audio with 3 jacks: How to config this ?

I'm not sure what to do then sorry

Hohoho

Member

Registered: 2007-06-23

Posts: 222

Re: 5.1 Audio with 3 jacks: How to config this ?

I have an Audigy 2 and all I had to do was unmute Surround and Center channels in alsamixer.

evert_

Member

Registered: 2007-07-27

Posts: 30

Re: 5.1 Audio with 3 jacks: How to config this ?

and the url because the preview isn't that clear : http://omploader.org/vMjgw

Last edited by evert_ (2007-08-22 21:21:39)

chippy

Member

From: London, ON - Canada

Registered: 2006-06-27

Posts: 15

Re: 5.1 Audio with 3 jacks: How to config this ?

Can your soundcard support 5.1 audio?

---

Go Go Power Rangers!

brebs

Member

Registered: 2007-04-03

Posts: 3,742

Re: 5.1 Audio with 3 jacks: How to config this ?

See wiki regarding IEC958.

xsdnyd

Member

Registered: 2007-04-28

Posts: 110

Re: 5.1 Audio with 3 jacks: How to config this ?

do you want to emulate the 5.1 sound? for example get sound from all 5.1 speakers when playing a stereo mp3 file?
then you can try this (put it in .asoundrc):

pcm.!default {
     type route
     slave.pcm surround51
     slave.channels 6
     ttable.0.0 1
     ttable.1.1 1
     ttable.0.2 1
     ttable.1.3 1
     ttable.0.4 1
     ttable.1.4 1
     ttable.0.5 1
     ttable.1.5 1
}

---

We can't stop here! This is bat country!!

brebs

Member

Registered: 2007-04-03

Posts: 3,742

Re: 5.1 Audio with 3 jacks: How to config this ?

Use instead:

pcm.ch51dup {

Because having it as the *default* would mess up proper surround sound in games that used the default.

Last edited by brebs (2007-08-26 10:35:53)

vacant

Member

From: downstairs

Registered: 2004-11-05

Posts: 816

Re: 5.1 Audio with 3 jacks: How to config this ?

I have a very cheap C-Media PCI CMI8738-MC6 6-channel sound card connected by three jacks to Logitech 5.1 speakers. I also have a headset for Skype connected to the onboard sound.

Here's what I know:

1) To always get the sound card module to load before the onboard sound module, I have added snd_cmipci to my "modules" list in /etc/rc.conf. This means the cmi card is always card 0, the module for the onboard sound gets loaded automatically later.

2) I have ~.asoundrc as follows:

# 6 channel dmix:
pcm.dmix6 {
    type dmix
    ipc_key 1024
    ipc_key_add_uid false
    ipc_perm 0660
    slave {
        pcm "hw:0,1"
        rate 48000
        channels 6
        period_time 0
        period_size 1024
        buffer_time 0
        buffer_size 5120
    }
}

# upmixing:
pcm.ch51dup {
    type route
    slave.pcm dmix6
    slave.channels 6
    ttable.0.0 1
    ttable.1.1 1
    ttable.0.2 1
    ttable.1.3 1
    ttable.0.4 0.5
    ttable.1.4 0.5
    ttable.0.5 0.5
    ttable.1.5 0.5
}

pcm.duplex {
    type asym
    playback.pcm "ch51dup" # upmix first
    capture.pcm "hw:0"
}

# change default device:
pcm.!default {
    type softvol
    slave.pcm "duplex"
    control {
        name "Software Master"
        card 0
    }
}

# for aoss
pcm.dsp "duplex"

pcm.dsp1 "duplex"

3) To allow amarok to play each speaker individually using a 6 channel DTS .wav file I added the following to my ~.xine/config

audio.device.alsa_surround51_device:plughw:0,1

4) You can download a 60MB 6-channel DTS test file here. It is in swedish but tests each speaker individually.

My info came from browsing the Alsa wiki