SX 690 is a real beast with an Hi-SPL Mid-Hi unit based on 1.4” dome tweeter and 1” dome supertweeter with resettable solid-state protection circuit. Cone are made with nature-proof high stiffness pressed-paper featuring innovative water/humidity resistant and anti-UV treatments. The double layer copper voice coil, wound on polyamide former ensures unparalleled power handling. New motors units are made of special Neodymium N38 H to obtain a minimum bulk and increased performance.