The ISP Technologies XMAX 218 Subwoofer has been carefully designed to provide a level of performance, both in terms of SPL ouput and low frequency extension, equal to or better than the best dual 18 cabinets. The 18-inch drivers are the latest state-of-the-art design. They feature massive finite element Analysis optimized magnet structures, dual spiders, triple cooling systems, 4-inch voice coils and a 25mm peak excursion. This results in outstanding 2200-watts RMS power handling for low power compression and high reliability. The cabinet also features a very large port, much larger than found on many dual 18 cabinets. This provides better linearity for higher output and lower frequencies. Combine all this with a low cabinet tuning, and deep, tight, high output bass is achieved. Standard with the system is a dual channel, 2000-watt RMS (4000-watt peak) amplifier that is specifically designed for use with the speaker. This amplifier features ISP's patent pending D-CAT high-current amplification technology, and is capable of driving the speakers beyond their safe operating limits. Dual cooling fans automatically switch on when needed. The height of 22.5 inches allows for enhanced truck pack with 94-inch internal truck widths. An optional dolly board with 4 castors is available.