[ubuntu-studio-devel] Ubuntu Studio and Pulseaudio

[Len Ovens]

On Sat, 12 Dec 2015, brian at linuxsynths.com wrote:

> can I safely remove pulseaudio?  It may be intefering with a synth I'm using, as
> I only use Jack for audio but for some reason pulseaudio is always lurking.
> 
> I saw that purging pulseaudio brings with it removing the ubuntustudio-desktop
> file and wanted to know if I needed to install another desktop first (xfce,
> etc)..

Pulse can be removed, but not by package removal. Removing pulse will 
remove lots of other things.

You say pulse "may be" interfering, which means you are not sure. So to 
check that out. Please note that if you are using ubuntustudio you are 
already using xfce.

The most common reason for pulse to interfere with something jack is the 
pa-jack bridge. If you have more than one audio device and jack is using 
one and pulse is connected to another (even if you are not using it) the 
two will interact. You can try either to remove pulses ability to see 
other devices:

pactl unload-module module-udev-detect
pactl unload-module module-alsa-card

and/or remove pulses ability to see jack:

pactl unload-module module-jackdbus-detect

Personally I use the first method all the time which efectively uses pulse 
only as a front end for jack. However, for low latency work, where jack 
needs to be set at less than 128/2, I add the second as well. (I can run 
my PCI sound card at 16/2 as a softsynth or guitar effect though 128/2 is 
generally good enough)

With both actions above, pulse still runs but with a dummy back end and 
very low cpu, but because it is still running any desktop application that 
requires pulse will not hang or fail.

I am working on an application/utility that will do most of this stuff 
automatically. It looks like it will not be done for the next cycle as we 
are past feature freeze (already  :P  ).

--
Len Ovens
www.ovenwerks.net