If there is any advice that anyone can offer me I would be grateful. Running iMac 10.11.3. A few years ago I purchased some JBL Creature speakers which have a great sound but cannot operate at low volume. As graphic designer I work on the desktop most of the day and like some background music. The speakers cut out at low volume, the only way to restore the sound is to increase the volume either via the speaker or via the iMac, turn the volume down a touch and within a few minutes it cuts out. I have tried the speakers on a windows system and all is fine. Its so frustrating!