I have used my Audiobox USB on my Macbook Pro 13" (from mid-2009 with Leopard, then Snow Leopard) since 2010 without a single issue and I’ve just switched to El Capitan OS (10.11.6).
The Audiobox works fine with everything (iTunes, GarageBand,…), except for Cubase LE4 - the software which was provided with the Audiobox. Cubase emits some white noise as soon as I play a track - which becomes almost impossible to hear as a result.
What I've noticed is that my MBP switches back to the internal speakers towards the end of the starting of Cubase and I have to manually switch the audio output back to the Audiobox, but it doesn’t do so normally: the volume knobs of the MBP function in spite of the fact that they are not supposed to when the Audiobox is plugged in.
The white noise I can hear seems to come from Cubase’s input, since there is a high level input signal that shows in the transport bar, even though Cubase has just been started and no song or project has been loaded yet, nor any instrument is plugged into one of the Audiobox input sockets. This signal shows in the transport bar, but no white noise can be heard yet, as long as I don't play a track or song.
Has anybody ever encountered such issue or has any idea what the solution may be? Thanks in advance.