Improve sound quality

[sanjuro]

I have realtek ALC861 and running fedora 17 LXDE 32bit. Are there some tips or tricks to improve sound quality? Because comparing the same audio source, in windows with realtek manager, the sound was better. As i see fedora LXDE is using pulseaudio. Should i set up pulseaudio as audio output in VLC player? thx.

[Fenrin]

if you are not happy with the sound quality when using pulseaudio, you could uninstall pulseaudio and install OSS instead. On some soundcards the sound quality when using OSSv4 is considerable better than when using pulseaudio.

here are rpm packages to install it: http://www.opensound.com/download.cgi

Before you install that make sure that you install kernel-devel (for a PAE kernel, you need kernel-devel-PAE) and kernel-headers. Also remove pulseaudio.

the archlinux wiki page lists some advantages and disadvantages of OSS compared to ALSA: https://wiki.archlinux.org/index.php/OSS

As alternative to the commercial licensed rpm package, you could also compile it from source. But that's a bit less comfortable to install and uninstall: http://www.4front-tech.com/developer...es/stable/gpl/

After installation reboot. To test if it works you can use osstest, as soundmixer you can use ossxmix. If you use suspend or hibernate, you must disable the sound first with soundoff (soundon to turn it on).

[stevea]

As much as you appear to have some knowledge of ancient OSS, your assertions about Pulse and comparing it to OSS is nonsense. Your site compare ALSA to OSS which is appropriate. Here is a brief, competent, description of pulseaudio
http://en.wikipedia.org/wiki/PulseAudio

PulseAudio is a sound server, a background process accepting sound input from one or more sources (processes or capture devices) and redirecting it to one or more sinks (sound cards, remote network PulseAudio servers, or other processes).

One of the goals of PulseAudio is to reroute all sound streams through it, including those from processes that attempt to directly access the hardware (like legacy OSS applications). PulseAudio achieves this by providing adapters to applications using other audio systems, like aRts and ESD.

In a typical installation scenario under Linux, the user configures ALSA to use a virtual device provided by PulseAudio. Thus, applications using ALSA will output sound to PulseAudio, which then uses ALSA itself to access the real sound card. PulseAudio also provides its own native interface to applications that want to support PulseAudio directly, as well as a legacy interface for ESD applications, making it suitable as a drop-in replacement for ESD.

For OSS applications, PulseAudio provides the padsp utility, which replaces device files such as /dev/dsp, tricking the applications into believing that they have exclusive control over the sound card. In reality, their output is rerouted through PulseAudio.
...

So PulseAudio primarily ROUTES sound - and is often not involve in actually collecting sound from sources nor driving it to sinks. Pulse on Fedora typically uses ALSA and can use OSS. You can setup some specific audio tools to use ALSA or OSS (if available) or aRts or pulse . It is possible that PA cancauses audio distortion in terms of jitter however I've never experienced this. Generally the advice to rip out PulseAudio without evidence is just wrong-headed voodoo.

The OP can install OSS and try it under Pulse, tho I have some doubts this will help - like the previous post it's just a shot in the dark.

=========

I Suggest that the OP try to diagnose the problem and consider the current configuration before trying random changes.

Package pavucontrol has a command of the same name that permits selection of the sound configuration (under the configure tab) and a primitive speaker test.

Package pulseaudio-equalizer contains the utility 'pulseaudio-equalizer-gtk' which presents you with a large selection of equalizer settings that can dramatically improve sound quality.

alsamixer and amixer have some controls or the alsa based interface -some of which are inaccessible to pulse.
alsa-info is a great script for collecting all the info about your sound configuration. It's worthwhile to use this to save a copy of known-working configs.

[Fenrin]

Originally Posted by stevea

As much as you appear to have some knowledge of ancient OSS, your assertions about Pulse and comparing it to OSS is nonsense. Your site compare ALSA to OSS which is appropriate. Here is a brief, competent, description of pulseaudio
http://en.wikipedia.org/wiki/PulseAudio
[...]

my comparison to pulse was actually just a little mistake. In the past I got it right and compared it only to Alsa: like here or here

my only assertion about Pulse Audio is that it has a bad impact on sound quality. It is a fact that it makes the sound latency worse than without Pulse Audio.

OSS first appeared about 5 years before Alsa, but this project gets still updates about yearly and version 4 is not even backward compatible to older versions. I wouldn't claim it is ancient.

Would you also claim that the Linux kernel is ancient although it is now quite different than in the 90's?

It's a shame that gnome-shell has pulseaudio dependencies otherwise I would just remove it, because I personally don't have any advantages from it.

[Gareth Jones]

Before messing around with drivers and other sound-related infrastructure, I'd start by checking the basic sound settings. Sometimes it can be something really simple, e.g. one problem I've had before (although not recently) is that PulseAudio's main volume defaulted to well over 100%, which caused clipping distortion. Simply turning the mixer volumes down to 100% fixed it...