This design is not by any means an audiophile thing, they do absolutely nothing to improve sound, at least not that I know of.

They are just made to keep my thick cables off the floor to prevent dust and to make it easier for my robot vacuum cleaner.

My speaker cables are 19 mm in diameter and they lightly snaps in place.

Printed on Prusa Core One in Galaxy PLA.
20% infill. 0.20mm layer height. Support on build plate only. Brim
I had to print mine in 50% speed but you might get lucky.