Do you run Mixbus with ALSA or JACK in Linux?

[kkrekula]

Hi all,

as Linux is my platform of choice for many years, I'd like to do my mixing in Linux too.

I have a question for you who have been using Mixbus in Linux for a while: If I only do mixing in Mixbus&Linux, does JACK have an advantage against ALSA?

For recording (or live use), I understand that JACK should have very little latency and therefore be preferred. But does it matter in Mixing?

Regards,
Kenneth

[x42]

As you may know, jack allows to inter-connect various applications [1] but if you don't use any 3rd party jack applications, there is no benefit to using jack.

Mixbus ALSA vs JACK is really just simplicity vs flexibility.

The ALSA backend that comes with Mixbus is very similar to jack's ALSA backend (jack uses ALSA under the hood, and they both share some code)

The Mixbus ALSA backend is be a tiny bit more efficient and has support for systemic midi latency compensation.
Jack on the other hand allows to use multiple soundcards [2] and other applications can connect to jack (e.g a web-browser or music player).

[1] http://jackaudio.org/applications/
[2] http://jackaudio.org/faq/multiple_devices.html

[lowen]

My experience is that if your Linux distribution has PulseAudio (and most do) then by running JACK you can be 100% sure that PA is out of the way and that system noises and such won't randomly introduce latencies. I use and have used JACK since Ardour 1.x days, so perhaps I'm biased. But I tried the ALSA backend, and PulseAudio got in the way a couple of times, and I experienced latencies and drops while mixing. I even use the JACK backends for Audacity and a few other packages (VLC, for instance), since it seems the likelihood of dropouts in the audio (or de-synchronized audio for VLC) is less for JACK than Pulse.

[kkrekula]

As you may know, jack allows to inter-connect various applications [1] but if you don't use any 3rd party jack applications, there is no benefit to using jack.

Mixbus ALSA vs JACK is really just simplicity vs flexibility.

The ALSA backend that comes with Mixbus is very similar to jack's ALSA backend (jack uses ALSA under the hood, and they both share some code)

The Mixbus ALSA backend is be a tiny bit more efficient and has support for systemic midi latency compensation.
Jack on the other hand allows to use multiple soundcards [2] and other applications can connect to jack (e.g a web-browser or music player).

[1] http://jackaudio.org/applications/
[2] http://jackaudio.org/faq/multiple_devices.html

My experience is that if your Linux distribution has PulseAudio (and most do) then by running JACK you can be 100% sure that PA is out of the way and that system noises and such won't randomly introduce latencies. I use and have used JACK since Ardour 1.x days, so perhaps I'm biased. But I tried the ALSA backend, and PulseAudio got in the way a couple of times, and I experienced latencies and drops while mixing. I even use the JACK backends for Audacity and a few other packages (VLC, for instance), since it seems the likelihood of dropouts in the audio (or de-synchronized audio for VLC) is less for JACK than Pulse.

Ok thanks for the feedback guys! Just what I wanted

Regards,
Kenneth

[x42]

My experience is that if your Linux distribution has PulseAudio (and most do) then by running JACK you can be 100% sure that PA is out of the way.

That is only true if you use jack2 (1.9.XX). but not jack1 (0.124ish).
Mixbus' ALSA backend also asks pulseaudio to release the device in the same way jack2 does.

But I tried the ALSA backend, and PulseAudio got in the way a couple of times, and I experienced latencies and drops while mixing.

There should really be no difference.
Would you mind filing a bug report? What system is that? Can you launch Mixbus from the commanline? It'll print some more info there.

One explanation: Mixbus' ALSA backend is less picky about rt-permissions. It will not fail if it cannot acquire realtime scheduling, Mixbus/JACK does fail, but then again if you use jack that can't be the issue.

[lowen]

My experience is that if your Linux distribution has PulseAudio (and most do) then by running JACK you can be 100% sure that PA is out of the way.

That is only true if you use jack2 (1.9.XX). but not jack1 (0.124ish).
Mixbus' ALSA backend also asks pulseaudio to release the device in the same way jack2 does.

I actually have qjackctl set to stop PA entirely. I'm using Jack 1.9.9.5 (aka Jack2). It's interesting that Mixbus' ALSA backend asks pulse to release; I'll have to take a look at it....

There should really be no difference.
Would you mind filing a bug report? What system is that? Can you launch Mixbus from the commanline? It'll print some more info there.
...

Ok. I can start it from the command line, but it will be a bit. The system is CentOS 7, and pluseaudio integration is pretty tight.

[allank]

Hi X42,

Can you please explain the difference in MIDI timing between the 2.
My understanding was that Jack ensured MIDI and Audio were kept in good sync and that ALSA did not. Is this not the cse?

It's a moot point for me at the moment, because the ALSA driver for my A&H Zed R16 can't run lower latencies than 256 buffers, whereas FFADO runs comfortably at 128 buffers (this seems to make a significant difference for me).. (more important at the recording stage) ..

Regards

Allan

---

To answer the OP, I use jack.
Until very recently I didn't have a choice, as I was forced to use FFADO.
However the ALSA driver can't run low latency (128 buffers) for my device. (A&H Zed R16)

[Ilaw]

I use Jack

[sonik]

Jack, because i use two RME HDSP9652 with jack-audioadapter as one soundcard, i couldn't do that with alsa.

[thekoala]

PulseAudio got in the way a couple of times, and I experienced latencies and drops while mixing.

You have to get rid of the pulse libraries as well, or they get loaded at login and continue to screw around with the audio system, even if the pulse daemon isn't running. Once they've been loaded, your audio system is hosed.

On a *buntu 64bit system, you will find these:

/usr/lib/i386-linux-gnu/libpulse.so.0
/usr/lib/i386-linux-gnu/libpulse.so.0.xx.0
/usr/lib/x86_64-linux-gnu/libpulse.so.0
/usr/lib/x86_64-linux-gnu/libpulse.so.0.xx.0
/usr/lib/x86_64-linux-gnu/ao/plugins-4/libpulse.so

Rename them or delete them. Reboot the machine, a logout/login doesn't do it. NEVER upgrade any pulse audio packages again, or they will be reinstalled. You should see a massive drop in cpu usage. All those glitches will go.

Find a ppa with the package "apulse". This will allow things like that microsoft video call program to work.

I have done this on three machines and three different versions of Ubuntu with the same effect.

Oddly enough, I now use jack+alsa plugin as my general audio system, and raw ALSA for Ardour/Mixbus. It's a pain sometimes, but the music is more important.