The SBA-218 is a compact high output permanent installation sub-bass loudspeaker employing two 18-inch long-excursion drivers in an optimally tuned vented enclosure. It is an ideal choice for applications requiring precise transient response and low bass extension in a compact very high output package. The SBA-218 is frequently employed as a single unit, or it can be used in multiples to create cardiod bass arrays. Its compact size fits well both under stages and in flown loudspeaker clusters.