Systems ListDIY18-Sound 21LW1400 sealed

System typeSealed
Driver18Sound 21LW1400
Driver Size21 "
Number of drivers1
Internal volume4.5 ft3
External volume6.12 ft3
Dimentions (Width Height Depth)23 " 23 " 20 "
Weight85 lbs


This 18 Sound 21 driver when placed into a small sealed enclosure produces the high F3 and rolled of response typical of pro woofers and other bass drivers with very high motor force. Also as is usual for pro woofers with light moving mass, high motor force and inductance combating measures in the motor, the response is efficient, flat and extended well past 100Hz and could probably be effectively used to 350 or 400hz in a pinch. Still despite the moderate xmax rating the huge SD helps this driver produce a generous amount of low bass output while the top end efficiency results in powerful dynamics above 40Hz. The extra mechanical clearance after the 21LW1400s stroke becomes non-linear, is an effective protection scheme that helps to prevent damage to the woofer both by limiting the cone excursion and causing audible distortion well before any damage. Thermal handling is good but not great as the woofer did show some compression effects from heat buildup.

rnA sealed system is not what is recommended for this driver or what it was designed to be used in. Typically the 21LW1400 would be used in a large vented, horn or bandpass system but clearly with some signal shaping ability involved to bring up the low end response it could make a good showing in a small sealed cab as well.