Too dumb to understand sound settings for overdubbing

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Petra-Sue
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Too dumb to understand sound settings for overdubbing

Post by Petra-Sue »

Hello @all,

I have severe troubles in setting up my Linux box (Mint 17.2 with XFCE desktop on a T500 ThinkPad) for a rather simple task: Doing sequential multitrack recording with Audacity (2.0.5) from a wind controller optimized synthesizer (DynaSample Xpression) delivering several line-outs that are normally fed to an attached active amplifier system but may be recorded via line-in as well.

In order to receive the line-in I attach an external SoundBlaster THX USB soundcard to the laptop (which by itself accepts microphone levels only). Opening the mixer I am confronted with a plethora of "sound cards" and their settings that partially interact with each other: HDA Intel (Alsa mixer), SB X-Fi Surround 5.1 Pro (Alsa mixer), Playback: Internal audio analog surround 4.0 (PulseAudio Mixer), ....

For getting the latency down I have used QJackCtl before in real-time settings, mostly for direct playing a wind controller (EWI USB) into some software synth (Swami, QSynth), and can manage the required connections of ins and outs for that task. Using Jack collaborating with Audacity for the present overdubbing task seems to create the respective channels dynamically though, so I cannot 'plug' them statically beforehand as I would expect them to be correct.

With wild, stochastic rearrangments of settings in ALSA mode I somehow managed at several times to get the effect that I wanted: Recording the next track with Audacity over line-in while hearing previously recorded ones over the laptop's line-out (i.e.: monitor loudspeaker plugged into earphones plug of the docking station or the laptop itself. I do not need to listen to the new track via the laptop as there is a speaker system directly attached to synth.) But it is always an absolute trial-and-error approach that I would love to get a bit of a system into.

Could anyone, please, comment on the mutual dependencies of the abundance of sound settings for the rather simple practical requirements? I'd love to understand them rather than doing a wild trip each time that eventually may lead to a useable setup - or even not.

Thanks a lot in advance!

Petra
asbak
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Re: Too dumb to understand sound settings for overdubbing

Post by asbak »

For getting the latency down I have used QJackCtl before in real-time settings, mostly for direct playing a wind controller (EWI USB) into some software synth (Swami, QSynth), and can manage the required connections of ins and outs for that task.
You can get lower latency operation (audio without xruns at 48K, 128 frames, 3 periods) with a PREEMPT or RT kernel which will need to be installed additionally. Higher latencies = bigger gap between playing softsynths and hearing the audio.
Using Jack collaborating with Audacity for the present overdubbing task seems to create the respective channels dynamically though, so I cannot 'plug' them statically beforehand as I would expect them to be correct.
It's possible to run a daemon like jack.plumbing which will scan for jack ports and automatically connect or disconnect them according to rulesets you have created.
So for example, if Audacity is set to use Jack, it creates PortAudio jack ports while a soundfile is playing or recording and those ports disappear once recording or playback stops.
jack.plumbing will then automatically make the connections when it detects the Audacity PortAudio ports.

There are more advanced configuration options in which one can create ALSA loopback soundcards and connect them to jack with alsa_in and alsa_out, then send the jackaudio (from the softsynth) to the virtual (loopback) soundcard, then record this with Audacity while it is set to ALSA device. That way there's no jumping around with connecting jack ports for Audacity.

There's some information here on how to achieve this but it probably isn't a good idea to just copy and use everything without understanding how to adapt it to your circumstances.
viewtopic.php?f=19&t=15160

Anyway, these configuration possibilities are not so simple to set up, but work really well once they have been implemented.
Some Focal / 20.04 audio packages and resources https://midistudio.groups.io/g/linuxaudio
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Petra-Sue
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Re: Too dumb to understand sound settings for overdubbing

Post by Petra-Sue »

Hello Asbak,

thanks for your answer, even though I have the feeling that it does not address the core of my question: As I explained I seem to get along with Jack and/or ALSA in general, but I am lost with respect to the interaction of the various settings of the sound system. All in all, there are some 10 to 20 individual settings or even more to be made in the mixer, and I do not grasp their relative connectivity. Is there something like a "wiring diagram" to help understanding?

If I use Jack (here via QJackCtl) for soft wiring there are additional settings about the sound card(s) as well that I cannot get the sense of.

I mentioned Jack only in the context that I am in general familiar with its softwiring capabilities (and needs), but the present task is the one of overdubbing, with everything coming from the external synth via line-in.

Cheers,
Petra
tnovelli
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Re: Too dumb to understand sound settings for overdubbing

Post by tnovelli »

Petra-Sue,

I'm getting great USB audio latency (~6ms) without fiddling with too many JACK driver settings... I think just 3 periods and the fewest frames-per-period I can get away with. I'm using Mint 17.1 with the default kernel... but instead of QJackCtl I'm using Cadence from the KXStudio PPA. You can use Cadence to stop PulseAudio if it's running, configure & run JACK, then re-run PulseAudio bridged to JACK. Also try Catia (fancy graphical patchbay) to show all your JACK connections... hopefully you'll see how to route the signals for monitoring.

It is totally overwhelming... don't expect to understand everything! It took me a few years to get comfortable and I'm still learning... and the software keeps improving (mostly!)
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Petra-Sue
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Re: Too dumb to understand sound settings for overdubbing

Post by Petra-Sue »

Hello Tnovelli,
tnovelli wrote:... I'm using Cadence from the KXStudio PPA. You can use Cadence to stop PulseAudio if it's running, configure & run JACK, then re-run PulseAudio bridged to JACK. Also try Catia (fancy graphical patchbay) to show all your JACK connections... hopefully you'll see how to route the signals for monitoring.
Just looked for it: It is not in Mint repositories. Scanning the various progs you mention I found respective descriptions of Carla, Catia, Cadence ..., but I am absolutely at a loss what the difference of them is pragmatically. They all seem to provide a patch bay for Jack channels. What is the sense to develop and install all three of them?

Even if I choose one of them (instead of QJackCtl) I guess I'll see the same effect as described above, namely: that audacity creates dynamic channels at the time of playing / overdubbing that are not there without the recording being activated, and therefore cannot be patched beforehand.

Isn't there something like a connectivity sketch that describes the internal interdependencies of the individual settings, or what connections should be created for some standard tasks (e.g. like mine described above, but other pragmatically described tasks with wiring diagrams would surely help too)?

Cheers,
Petra
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Petra-Sue
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Re: Too dumb to understand sound settings for overdubbing

Post by Petra-Sue »

Small remark to this topic, before some of you get smoke above your heads:

I surfed the net a bit further and found the remark that one must not mix internal sound card connections and USB soundcard ones. I did so on my last tries, and somehow got it to work now and then. Just an hour ago I checked the non-mixing suggestion with an analogous headset with both plugs (earphone + micro) put into the USB soundcard, and everything worked as expected. No crosstalk from 1st track to 2nd one.

Tomorrow I will check with the line-in connector and report.

Cheers,
Petra
glowrak guy
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Re: Too dumb to understand sound settings for overdubbing

Post by glowrak guy »

I use a usb guitar input, with maudio pci soundcard output. No big issues.

I think you are heavily enough invested in ewi, to get a desktop computer, 2nd hand,
and run a focussed audio distro, or a minimalist distro with just audio added to it.
Use a good pci soundcard, and eliminate these muse-killing complexities.

This would be both more powerful than the 500, and less complicated,
so you can focus on recording/performing. Mint is a swiss army knife distro,
when a butter knife is all you need. :wink:
I do have Mint on an external drive, but I removed most of the apps via synaptic,
and then added kx-studio repositories to install only what I use, or am curious about.
I use it to boot an old desktop computer with maudio pci soundcard.

For now, in audacity, imagine a 20 second solo in a recording that you want to improve.
You can select that 20 seconds, and amplify the volume lower, to barely audible,
or completely silent. Start recording a new track, and play as desired in those 20 seconds.

When you have a performance you like, make sure you amplify the original 20 seconds
down to zero, and export the track. Audacity will prompt you to let it blend the two tracks.
Play the new edited track, and verify you like the timing of the intro/exit to your 'overdub',
add/delete a little between-note-ambience as needed.
Cheers

(Of course now I want an ewi. (a reoccuring condition. Looking around at what to sell first...)
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Re: Too dumb to understand sound settings for overdubbing

Post by Pablo »

audacity creates dynamic channels at the time of playing / overdubbing that are not there without the recording being activated, and therefore cannot be patched beforehand
True, but there is a work-around: Just after activating record, press the pause button. Then make the jack software connections and press pause again to begin recording.

If you find this very annoying, maybe you wish to take a look at ardour.

Cheers, Pablo
tnovelli
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Re: Too dumb to understand sound settings for overdubbing

Post by tnovelli »

Petra-Sue wrote: Just looked for it: It is not in Mint repositories. Scanning the various progs you mention I found respective descriptions of Carla, Catia, Cadence ..., but I am absolutely at a loss what the difference of them is pragmatically. They all seem to provide a patch bay for Jack channels. What is the sense to develop and install all three of them?
If you follow the instructions under Repositories at http://kxstudio.net/ then you'll see the kxstudio packages. Those programs aren't the same. Cadence is like QJackCtl, Catia is just a patchbay, Carla does a lot more (plugins, sessions, etc.. probably overkill for you).

Pablo's absolutely right, you need a better recorder than Audacity. Ardour is the big one... I prefer Qtractor myself... and I wish there was something more streamlined but I haven't seen anything else that's really finished and usable.
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Re: Too dumb to understand sound settings for overdubbing

Post by ssj71 »

I also reccommend using ardour, or qtractor or the non-suite. I personally favor ardour. Audacity is pretty impressive and not too hard to understand, but once you are trying to get into a multi-track recording setup, you'll find audacity a bit wonky to work around. I did at least. There is a somewhat steep learning curve for a full-featured DAW like the one's I've listed but its well worth it, and the concepts are applicable to most any other daw.

Doesn't answer your question at all, but its something to consider.
_ssj71

music: https://soundcloud.com/ssj71
My plugins are Infamous! http://ssj71.github.io/infamousPlugins
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glowrak guy
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Re: Too dumb to understand sound settings for overdubbing

Post by glowrak guy »

Petra-Sue wrote: a rather simple task:
Could you be more precise as to what you are recording, for example, 'I'm recording a piano-flute duet,
and want to overdub part of a flute solo' etc.' The details could make a difference in your options.
Cheers
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