As far as the Bananas are ok. I used it with a 6 mm cross-section. I was unsure at first because my purpose was not indicated's 100%. But it is. However, after that is then final. More like 6mm cross-section is in no way. The two screws holding the respective per Banana, the cable is tightened, is easy to screw. Everything can be explained by itself. Unfortunately, these are some of inferior quality, so I therefore depart a star. Once you palmed it a little harder, it can happen that splinter easily. If you use a 6 mm cross-section, the caps are no longer the screws are screwed because survive to attach the cable. Did not bother me personally, however.
As regards phonetic optimization: I had connected a 2.5mm cross-section incl. Bridge. Well I used bi-amping with a 6mm cross-section. I can hear the difference, not others certainly. But this may be due to general improvement of the cross-section and not solely to the Bananas.
