B&W MM-1 Speakers Incompatible with High Sierra

My Bowers & Wilkins MM-1 computer speakers no longer work. They were beautifully crispy speakers and **** expensive. The MM-1 Programmer application has a white line running through - meaning, I think, that High Sierra no longer recognises it. I've contacted B&W who say it's an Apple problem. Is there anything I can do to get these speakers working again, please? BTW, they are connected to my iMac via USB. Thanks for any help.