Increasing ALSA's buffer size

[j_e_f_f_g]

QjackCtl; I don't think changing the Periods/Buffer value will affect ALSA's buffer size.

It should do exactly that... but only for apps that use JACK. If the app uses Pulse Audio instead, then you need to edit some PA config file. Otherwise, if the app uses ALSA (or OSS) directly, then it controls its own buffer size, and should have a "preferences/setup screen" to change the size.