[LAU] rtirq

[Ralf Mardorf]

On Thu, 19 Mar 2015 09:07:34 -0700 (PDT), Len Ovens wrote:
>So I have to ask myself if what you are hearing is just the 
>effects of a slow standard MIDI transport before the info even gets to
>the computer.

You can do an experiment, assumed you still own old computers and tapes.

Tape synced to the Computer by SMPTE (Atari) or by Click (C64). Record
a MIDI synth and after that record the same synth on another tape track.
This will double the synth sound, all you get is a phasing, that
doesn't move.

Do the same with a Linux or Windows PC. Record a track with Qtractor or
Cubase and after that record the same external synth on another
Qtractor or Cubase track. Sounds do not start at the same time, there's
always audible shift, comparable to slow early reflections and the
phasing is moving.

It's not a limitation of MIDI.

However, I wont discuss this again, I just want to know if RTC is
needed in the rtirq config for audio (ALSA/jackd), assumed jackd
doens't start with "--clocksource OR -c h(pet)". And should rtirq
config include an entry for HRTIMER/HPET? Is it possible to add
HRTIMER/HPET to the rtirq config (e.g. in addition to RTC) and what is
the name of such an entry?

Regards,
Ralf