Using-JACK

In order to obtain high quality audio and avoid dropouts, under-run or overrun errors during audio recording or playback it is advisable to run JACK. Since it is a Unix process which acquires top priority you should use it only for sound purposes. You normally start JACK in a terminal window by issuing the following command:

         jackstart -d alsa -d hw -r 44100        

Please notice that the -r follows the audio sampling rate. If you are working with CLM instruments you might want to use a lower sampling rate like 22050. Provided your sound-card will have this sampling rate available (not in the case of synchronized cards like the Delta 1010's) you might want to start jack by issuing the following command:

         jackstart -d alsa -d hw -r 22050        

In the case of a real-time situation like a concert situation, you can give JACK priority over all the other Linux processes with this options in the jackstart command:

         jackstart –realtime –driver=alsa        

WARNING: When you are done with your audio or sound job please make sure to quit or stop the JACK process by issuing:

         C-c  [control-c] sequence        

Alternatively you might want to use the Qjackctl GUI (graphical user interface) for starting and stopping JACK manually with a mouse click. Qjackctl is found at the sound & video tab of the main menu. See here.