Crackling sound

English Hardware
#1

Hi,

I have installed SuSE 11.0 on a system as follows:
ABIT AN78GS motherboard (nVidia Geforce 8200)
AMD 5200 dual core processor
2 GB ram (Kingston)
500 GB SATA hard disk

I have installed the nVidia driver for the graphics but found none for the on-board sound.

The problem I have is that all system sounds are crackling and sound like a really bad physical connection. Strangely, when I use Amarok to play music the sound comes out very clean with only the very infrequent crackle. System sounds also appear to be reverberating as if there is an echo.

Following a previous bit of advice I got I used YaST to install libxine1 and libxine1-codecs, but this did not solve the problem.
There is varying degree of noise on DVD playback with VLC and on the BBC IPlayer.

The noise is quite disturbing. Is there any configuration/driver I need to get this right?

Thanks,

Abe

#2

Your sound driver in opensuse is provided by the “alsa” application.

Check your mixer settings. Back off your master volume and PCM volume to 65% or so. The actual optimal % figure varies from PC to PC.

Yes, on openSUSE-11.0 its best to replace the Novell/SuSE-GmbH packaged xine-lib with the Packman packaged libxine1. I also recommend you install the Packman packaged libffmpeg0 (not the videolan packaged version) , which will pick up in its dependencies many codecs that you should have.

vlc is notorious for playing with distortion. You must keep the volume levels on the vlc volume control very low to avoid distortion.

#3

Many thnkas for the advice.

Since Alsa manages my audio device, and since it has done so successfully under SuSE 10.2, the problem must be with the actual hardware.

I dropped the volume to around 65% as suggested and the noise effects are smaller, but they are still present.

I also installed libffmpeg0 as advised but have not had the chance to check the sound quality on DVD playback as yet.

I guess I will have to live with some noise until I find a solution :expressionless:

Abe

#4

There is a possibility that this has been observed by others with the same hardware, and some investigation into this could provide improved audio output.

If you wish to investigate this further, then more information would be needed (by me). To provide more information, with your PC connected to the internet copy and paste the following into a gnome-terminal or konsole:

wget -O alsa-info.sh http://www.alsa-project.org/alsa-info.sh && bash alsa-info.sh

When the script completes it will pass you a URL. Please post that URL here.

Also, please copy and paste the following one line at a time into a gnome-terminal or konsole and post the output here.rpm -qa | grep alsa
rpm -qa | grep pulse
rpm -q libasound2
uname -a
cat /etc/modprobe.d/sound
cat /proc/interrupts
cat .asoundrc

#5

Thanks, I have done as you suggested. The URL is:
http://www.alsa-project.org/db/?f=85e178e08a51bcb1001d7179d1bc5e0267958ddb

Also, please copy and paste the following one line at a time into a gnome-terminal or konsole and post the output here.rpm -qa | grep alsa
rpm -qa | grep pulse
rpm -q libasound2
uname -a
cat /etc/modprobe.d/sound
cat /proc/interrupts
cat .asoundrc

The results are as follows:

>rpm -qa | grep alsa
alsa-plugins-1.0.16-57.1
alsa-firmware-1.0.16-24.1
alsa-oss-1.0.15-48.1
alsa-utils-1.0.16-35.1
alsa-plugins-pulse-1.0.16-57.1
alsa-1.0.16-39.1

>rpm -qa | grep pulse
libpulse0-0.9.10-26.5
libpulse-browse0-0.9.10-26.5
gstreamer-0_10-pulse-0.9.7-42.pm.1
libpulse-mainloop-glib0-0.9.10-26.5
vlc-aout-pulse-0.9.8a-1.7
pulseaudio-0.9.10-26.5
alsa-plugins-pulse-1.0.16-57.1
pulseaudio-utils-0.9.10-26.5
libpulsecore4-0.9.10-26.5

>rpm -q libasound2
libasound2-1.0.16-39.1

>uname -a
Linux nina 2.6.25.18-0.2-default #1 SMP 2008-10-21 16:30:26 +0200 i686 athlon i386 GNU/Linux

>cat /etc/modprobe.d/sound
options snd slots=snd-hda-intel

M71A.golWCaVMRzB:nVidia Corporation

alias snd-card-0 snd-hda-intel

>cat /proc/interrupts
CPU0 CPU1
0: 118 6 IO-APIC-edge timer
1: 0 1684 IO-APIC-edge i8042
6: 0 5 IO-APIC-edge floppy
7: 1 0 IO-APIC-edge
8: 0 1 IO-APIC-edge rtc0
9: 0 10 IO-APIC-fasteoi acpi
14: 6 8701 IO-APIC-edge ide0
20: 2 987 IO-APIC-fasteoi ehci_hcd:usb3, nvidia
21: 0 1672 IO-APIC-fasteoi ohci_hcd:usb2, HDA Intel
22: 16 17436 IO-APIC-fasteoi ohci_hcd:usb1
23: 0 1 IO-APIC-fasteoi ehci_hcd:usb4
218: 76 105378 PCI-MSI-edge eth0
219: 38 33988 PCI-MSI-edge ahci
NMI: 0 0 Non-maskable interrupts
LOC: 75524 80170 Local timer interrupts
RES: 28547 10647 Rescheduling interrupts
CAL: 400 294 function call interrupts
TLB: 1202 587 TLB shootdowns
TRM: 0 0 Thermal event interrupts
SPU: 0 0 Spurious interrupts
ERR: 1
MIS: 0

>cat .asoundrc
cat: .asoundrc: No such file or directory

#6

From the diagnostic script I note this in your mixer:
!!Amixer output
!!-------------
!!-------Mixer controls for card 0 [NVidia]
Card hw:0 ‘NVidia’/‘HDA NVidia at 0xfe020000 irq 21’
Mixer name : ‘Realtek ALC888’
Simple mixer control ‘Surround’,0
Capabilities: pvolume pswitch
Front Left: Playback 2 [6%] -43.50dB] [on]
Front Right: Playback 2 [6%] -43.50dB] [on]
Simple mixer control ‘Side’,0
Capabilities: pvolume pswitch
Front Left: Playback 2 [6%] -43.50dB] [on]
Front Right: Playback 2 [6%] -43.50dB] [on]
Simple mixer control ‘Line’,0
Capabilities: pvolume pswitch
Playback channels: Front Left - Front Right
Front Left: Playback 2 [6%] -31.50dB] [on]
Front Right: Playback 2 [6%] -31.50dB] [on]
Simple mixer control ‘IEC958 Default PCM’,0
Capabilities: pswitch pswitch-joined
Mono: Playback [on]
Simple mixer control ‘Capture’,0
Capabilities: cvolume cswitch
Front Left: Capture 10 [32%] -1.50dB] [on]
Front Right: Capture 10 [32%] -1.50dB] [on]
Simple mixer control ‘Capture’,1
Capabilities: cvolume cswitch
Front Left: Capture 0 [0%] -16.50dB] [on]
Front Right: Capture 0 [0%] -16.50dB] [on]I’m trying to understand your mixer settings. Is it necessary for your to have surround sound ON with low volume levels? Can you switch it OFF if not using? Same for some of your microphone capture settings. You have them on at low volume levels. If you are not using them, can you switch them OFF? Also your IEC958 digital audio. Is it necessary to be ON ? Can you switch it OFF ?

Did you try going to YaST > Hardware > Sound > Other > Volume and move your volume levels UP there, and then back off some more on your mixer master and PCM volume levels?

I note you have an ALC888 on a CMedia CM8738. I’ll take a look at this to see if I can discover anything.

#7

Ok, I note your PC has a CMedia CM8738 ALC888. Searching the alsa web site for the ALC888 I obtain this:
Search results - AlsaProject

which indicates there have been updates to the ALC888 since the version 1.0.16 of alsa which is on your PC. Hence you could consider updating your alsa driver to see if that helps. If it does not, you could keep that alsa update on your PC and then try some model options in the /etc/modprobe.d/sound file.

BUT FIRST, please try my recommendation in the post before this. That is a fundamental check that must be done.

OK, assuming you tried what I recommended in the previous post of mine, and assuming that it did not help, then you could update your version of alsa by sending the following 6 zypper commands (one at a time in sequence) from a gnome-terminal or a kde konsole, with root permissions, while your PC is connected to the internet:

zypper ar http://download.opensuse.org/repositories/multimedia:/audio/openSUSE_11.0/ multimedia 

zypper install alsa alsa-utils alsa-tools alsa-firmware alsa-plugins alsa-plugins-pulse alsa-oss libasound2

zypper rr multimedia

zypper ar http://download.opensuse.org/repositories/multimedia:/audio:/KMP/openSUSE_11.0_Update/ multimedia

zypper install alsa-driver-kmp-default

zypper rr multimedia

then restart your PC and test your audio quality. Be certain to check your mixer very carefully (and also YaST > Hardware > Sound > Other > Volume as noted above).

If that still fails, then we can apply an edit to your /etc/modprobe.d/sound file. You noted this:

I also note from the ALSA-Configuration.txt file for 1.0.18a of alsa the following list of model options for the ALC888:

	ALC883/888
	  3stack-dig	3-jack with SPDIF I/O
	  6stack-dig	6-jack digital with SPDIF I/O
	  3stack-6ch    3-jack 6-channel
	  3stack-6ch-dig 3-jack 6-channel with SPDIF I/O
	  6stack-dig-demo  6-jack digital for Intel demo board
	  acer		Acer laptops (Travelmate 3012WTMi, Aspire 5600, etc)
	  acer-aspire	Acer Aspire 9810
	  medion	Medion Laptops
	  medion-md2	Medion MD2
	  targa-dig	Targa/MSI
	  targa-2ch-dig	Targs/MSI with 2-channel
	  laptop-eapd   3-jack with SPDIF I/O and EAPD (Clevo M540JE, M550JE)
	  lenovo-101e	Lenovo 101E
	  lenovo-nb0763	Lenovo NB0763
	  lenovo-ms7195-dig Lenovo MS7195
	  lenovo-sky	Lenovo Sky
	  haier-w66	Haier W66
	  3stack-hp	HP machines with 3stack (Lucknow, Samba boards)
	  6stack-dell	Dell machines with 6stack (Inspiron 530)
	  mitac		Mitac 8252D
	  clevo-m720	Clevo M720 laptop series
	  fujitsu-pi2515 Fujitsu AMILO Pi2515
	  3stack-6ch-intel Intel DG33* boards
	  auto		auto-config reading BIOS (default)

One can apply those one option at a time to the /etc/modprobe.d/sound file, then restart one’s sound from a konsole with root permissions by typing “rcalsasound restart” (no quotes) and then restart one’s mixer and test one’s audio. For example, if one’s PC has only 3 I/O jacks for audio, one could try:options snd slots=snd-hda-intel
options snd-hda-intel model=3stack-dig

M71A.golWCaVMRzB:nVidia Corporation

alias snd-card-0 snd-hda-intel
then restart alsa with “rcalsasound restart” (with root permissions) and then restart one’s mixer and test the sound quality. For example if one’s PC has 6 I/O jacks for audio, one could instead of “3stack-dig” try “6stack-dig” ]options snd slots=snd-hda-intel
options snd-hda-intel model=6stack-dig

M71A.golWCaVMRzB:nVidia Corporation

alias snd-card-0 snd-hda-intel
then restart alsa with “rcalsasound restart” (with root permissions) and then restart one’s mixer and test the sound quality.

One could try each option in that list to see if any one improves the quality of one’s audio.

Good luck.

#8

Even when I set the surround and 3D to off in the mixer, every time I play a test sound (from the “other” option under YaST) I find that the mixer settings have been turned “on” again. So I set them to zero level in the mixer instead.

My motherboard (Abit AN78GS, nVidia Geforce 8200) has a 7.1 surround sound system on board, but due to the problems I was having I also added an old C-Media (CMI 8738) PCI sound card, to see if this gives me a better sound. Unfortunately this did not change the distortion I hear, but this is why you see some refernces to it. I have now removed it from the configuration.

Did you try going to YaST > Hardware > Sound > Other > Volume and move your volume levels UP there, and then back off some more on your mixer master and PCM volume levels?

Yes, I did. The master and PCM were dropped to 40% while the front was set to 90%. The overall sound is very weak now but the distortion is still there. If anything, the sound is clearer when master and pcm are at 100% and the front channel is down to about 40%/ - but there is still distortion even then.

#9

Many thanks - the problem is now solved. The update of ALSA did the trick, and now the sound is clear even when front, master and PCM are all set to 90%.

You have been a great help and I am very grateful!

#10

Congratulations ! Thanks for sharing your solution.