latency correction - jack_iodely values constantly increasing
I just bought a MAudio Fasttrack Ultra 8R an use it on my Notebook with Ubuntu Studio 11.10 (3.0.16-generic Kernel)
I have big problems with the latency correction of Jack and Ardour.
To be safe from XRuns I set Jack to 1024 Frame/Period and 44100Hz, 3 Periods/Buffer giving me 67,7ms Latency as reported by QJackCtl.
When I route Ardours Click out to an Audio Track within Ardour and record that then afterwards play the track back with the Ardour-Own-Click still on, I get obvious flams.
Next I started to play the recorded Click-Track back and re-record it with a microphone over the speakers - again flaming (if I turne on the built in click again I even got a triple flam).
Then I started measuring the delay in Frames in Ardour, deviding that by two and used those value as In- and outputlatency in QJackCtl. After a bit of trial an error I figuerd out some values that got the two recoded tracks in Sync.
Without chaning those values I retried the same configuration, and again - flaming, the microfone recorded track was too late.
Really confused now I tried out jack_iodely simply over the speaker-mikrofone setup (Jdelay out to speaker, mirkofone to Jdelay in)
those results now completely confuse me: as I run the test for about 30sec the values shown by jdelay constantly increased: from 4339.363 to 4535.423 in the end.
As I can not control the DSP-Mixer in the Fasttrack Ultra 8r under Linux I don't dare to directly connect an output to an input as I might get a feedback loop then - the DSP-Mixer in the device always connects the inputs to the outputs.
I hope somebody has an idea about what I can do.... actualy I could still return the Fasttrack Ultra to my Dealer and get my money back but that would be the last option, because I could not find any other USB-Multichannell-Adio-Device at that price that is ALSA compatible.
I hope someone out there can help me. Thank you for you patients reading all this so far already.