[linux-audio-dev] Linux Audio Experiences

[Dan Harper]

Hi all (sorry for the cross-post, but this may not be just a problem
with Ardour),

Over the last week and the weekend, I took to recording a song in full
using Jack, Hydrogen, Ardour and Jamin.  I'm not sure if Ardour/LAD is
the best place to send this, but some things that I noticed may be
across different software, but I thought I'd list a few issues that came
up, as well as some delights.  I'm not on the Jack or Hydrogen lists,
but if this is a Jack or Hydrogen problem, please let me know and I'll
post it there.

The main problem I had was the sync between Hydrogen and Arodur.  I had
Hydrogen set as Jack transport slave, and Ardour as master.  Both
programs were set at 130 bpm, but if I recorded something to a track in
Ardour, and then played it back, it sounded fine (in time), but on the
screen, the recorded material does not line up with the bar lines in
Ardour.  The recorded stuff appears a few millimetres before the bar
line.

Another interesting thing was if I changed the (period?) in Jack from
512 to 1024, the Hydrogen playback was out of time to the Ardour
playback, if I switched it back to the original setting it was recorded
in, it was fine.

I had a few stability problems, but I didn't test them very much, it
seemed to be realted to having certain plugins enabled in Ardour.  Jack
was kicking Ardour out when a particular plugin was being used.  I'll
have to test that another time to get more detail.

Overall though, things went fairly smoothly.

The result of the weekend is available at http://danharper.org/songs.php
if anyone is interested.  It was all done in Linux:

HYDROGEN -> ARDOUR ------------------------> JAMIN -> QARECORD
             Electric Guitar (3 tracks)                
             Vocals (3 tracks)
             Bass Guitar
             Vocals Bus
             Hydrogen Out to an Ardour Bus
             Master Bus

Feel free to give feedback on the song, mix, and mastering.  One thing
that I loved was Jack. Getting a nice sounding mix and master was so
easy because I could change a track level in Hydrogen, and immediately
hear the results through Jamin.  Same also if I needed to change a
plugin parameter or track level in Ardour, the results were immediate.
There is no other set of audio tools around that I know of that can do
this.  A very powerful and useful feature of the design of Jack and its
clients.

Overall, I should mention that the majority of my time was spent
wrestling with LADSPA plugins.  Some cased reliability issues in Ardour
(see above, more info to come).  Some gave me some OK sounds, but I have
noticed in the mixdown that the guitar orverdrive doesn't have a nice
warm sound.  I can't recall the exact plugins I used from memory, but I
did find it hard to find plugins that would give me a nice warm sound on
guitar tracks.  Maybe that is something to improve upon.


Dan