[iiwusynth-devel] Newbie getting warnings and pops/clicks

[Markus Nentwig]

Hi,

the warnings are OK, I get the same.
You can get rid of them if you run the synth as root or do chmod a+s
/usr/bin/iiwusynth.
It's not necessary, but it gives the synth higher priority. That alone
can avoid dropouts.

Then try different options for buffer size and fragment number (This
applies both to OSS and ALSA driver. But the same device can behave
differently, for example Maestro3 chip).
The command line options are -c (fragment number) and -z (buffer size in
frames), as in "iiwusynth -c 16 -z 64 johnnypad.sf2".
Find out, what your card can handle. For both parameters, smaller
numbers result in lower latency, but less tolerance against dropouts.
For example (from memory, can't guarantee for those)
Maestro 3 under OSS: -c 16 -z 64
Same under ALSA: -c 16 -z 128
Edirol UA-1 USB: -c 3 -z 45
Edirol UA-100 USB: -c 4 -z 45, produces periodic dropouts nonetheless
(driver problem).
Hammerfall DSP: -c 2 -z 64

If that does not help, look at the HDD lamp - do the dropouts coincide
with the OS flushing the buffers?
One cause of regular dropouts on my machine is the window manager
(icewm) trying to read the APM battery status once per second. When I
disabled the battery display, dropouts were gone.
If in doubt, kill X and run the synth from the console.

Let me know, if you succeed!

-Markus