Nordost Red Dawn 2

Like banana-plugs, just put them in the hole. 

Warning: if you`re system appears to sound a bit on the dry side it is most likely because of this Nordost-wire. Red Dawn is not as bad as Blue Heaven but still dry

If they don't look like these they have been re terminated.
https://nordost.com/speaker-cables.php
 

They look like the Leifstyle; the diameter is insufficient to fit the back of the speaker or amp receptacle as a banana would.

Use an appropriate diameter screwdriver the expand the diameter.

I've had many pair of Nordost Cables.  At points I've had full looms of Frey 2 and Valhalla 2.  The way they fold them over at the termination makes me scratch my head.  As tablejockey said, they need to be adjusted.  
IMO Nordost makes good products.  Effective if everything else is right.  They can add magic.