"Compact, powerful reinforcement systems, the 4662A and 4663A offer high efficiency, vivid, natural sound (even at very high levels), and a controlled dispersion pattern for indoor or outdoor reinforcement applications. These systems are capable of high acoustic output, can handle large amounts of power, and are designed for reliability and durability. Outdoors, with no support from room acoustics, either system will produce an impressive 117 dB at 3 m (10 ft) when driven at its rated power of 150 watts continuous pink noise. Where higher sound pressure levels are desired, systems may be paired to produce up to 6 dB more SPL than a single unit, with consequent improvement in peak power capability". The "close coupled" phrase is from a similar blurb on their site.......