The 18SW2200 v2 response and accuracy to low notes will surprise any listener and is great for either bandpass or bass reflex systems and has a specially designed Forced Air Cooling System to ensure proper cooling for long hard play in your pro audio environment. A reinforced cast aluminum frame increases rigidity and resists frame flex. Spring-loaded speaker terminals allow for easy speaker wire connection and the use of a dual spider suspension, mated to a cotton M-Roll surround and ribbed cone (all attached with a special resin) offer precise movement along its impressive 9mm Xmax.