[LAU] online calls with decent auido for music lessons

Lorenzo Sutton lorenzofsutton at gmail.com
Fri Mar 19 15:35:27 CET 2021

Hi David,

On 19/03/21 15:22, David Kastrup wrote:
> Lorenzo Sutton <lorenzofsutton at gmail.com> writes:
>> - Jamulus [4]: audio-only, realtime online jamming-oriented with
>>    public 'servers', jack-native. This was actually real fun to test
>>    and play with. I tried some close-by servers and jammed a bit in the
>>    central one. With 128 frames set in JACK and using Jamulus' own
>>    direct monitoring latency was definitely acceptable and the audio
>>    quality pretty good. Audio-quality and music-friendliness wise this
>>    is probably the nicest to use. Only thing for a teaching setting is
>>    the public-only servers (the documentation mentions 'private' ones,
>>    but I haven't looked into if this is possible without actually
>>    'hosting' a server),
> I could rent one out to you, assuming my cloud provider has some
> facility in reasonable vicinity to you.
> As a first measure however, you could easily run one yourself on your
> own computer (running Jamulus with the -s option runs one on your
> computer).  This requires punching a port through the firewall in your
> Internet router and either phoning your external IP address to the
> student (depending on your Internet provider, it may be fairly constant)
> or setting the router up to communicate with a DynDNS account giving you
> a constant name.
> If your computer has enough performance and you connect your own Jamulus
> client to "localhost" rather than going through the network, for a
> one-on-one session it may work.  However, it means that the student
> audio goes in and out the student's Internet connection and in and out
> your own Internet connection.  Using a cloud server has the advantage of
> halving the number of home-level routers that the student roundtrip (not
> your own one) has to pass through.  And the student is less likely to
> routinely deal with that latency than you would be after a while.
> Of course, this consideration is moot if there is no cloud computing
> facility in closer "networking" vicinity than the trip through your
> private connection would take.  It may also depend on whether you and
> your student share the same provider, making it more likely that routing
> is able to bypass the central "Internet Highways" that tend to be "near"
> the cloud servers.

That all makes sense and thanks for the tips and kind offer... There is 
the 'speed of light' factor after all.

Thing is.. _I_ amd the student (blush..) here, so the idea is not to 
over-bourden my teacher who is probably already having to cope with 
setting-up the calls, schedules etc. :-)

I would be interested to see if I can actually get my band to try this 
out since it's months we can't play together live :-(

>> there is a workaround via soloing or muting others, but I don't think
>> most teachers (nor students) would feel comfortable with anyone
>> possibly coming in and listening to the lesson. Also video should be
>> provided via some other tool and, of course, all parties need to have
>> the software installed.
> You get used to doing without.
>> That said this software is really well made and fun to use.  (aside
>> note there were a couple of 'troll' events in one of the public
>> servers, and although they say don't feed the trolls 'audio trolling'
>> can hurt your ears...
> That sounds more like the typical "instructions are just
> recommendations" newbie not taking serious the need to use headphones
> when working without echo compensation and auto-ducking.
> You know, like the only person in the conference call not affected by
> echoes after they figured out they could just switch off echo
> compensation without having their connection deteriorate.

Let's give them the benefit of doubt... Raise hands who hasnt forgot to 
turn the amp down before unplugging a jack, etc. The user in question 
did have a somewhat trollish name, but - again - ignoring them did work 
eventually :-)
>> Software:
>> - Jack
>> - Zoom H5 shows 4 inputs in jack: the L/R mics and the inputs 1 and 2
> Oh, can you just put the headphones right next to the mics (makes
> astonishingly little difference in comparison to direct connections) and
> use jack_iodelay for measuring out the latency of the H5 with your
> settings?

What exactly would you like me to measure? Roundtrip latency of _my own_ 
signal when using Jamulus, or...?

> Numbers are surprisingly hard to come by for any audio interface.

So true...

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