Sound issues on IMac

[Tjclark12]

Hi All,

Here's an unusual one! There is no sound when any student logs in to an IMac we have and loads Garageband or Logic.

 

I have to go into preferences, audio, output and change to iMac speakers. This causes problems because, although we can then hear the sound, we cannot manipulate the sound within the project.

 

No other Mac does this.

Could there possibly be a mishap with Garageband on this mac?

 

Any help is appreciated, thanks