Systems ListDIYTC Sounds LMS Ultra 5400 18 Sealed

System typeSealed
DriverTC Sounds LMS-Ultra 5400
Driver Size18 "
Number of drivers1
Internal volume4.2 ft3
External volume6.16 ft3
Dimentions (Width Height Depth)22 " 22 " 22 "
Weight130 lbs
Aprox. Price$1150 USD


TC's heaviest driver has long been revered as one of the best performing drivers on the market and the results of testing it in a sealed enclosure give good indication of why. The response shape is flat and extended past 300Hz with no hint of the inductance peak shown in other big sub drivers. The sensitivity is not bad at about 90dB considering that the mms is over 500g. The extra large, extra long 4" LMT voice coil on a titanium former and the quad stack of 10" diameter magnets adds up to excursion that is linear over the entire useful stroke of the suspension. Indeed the suspension and mechanical clearances are the limiting factor but they do not become a factor until the LMS Ultra is already displacing a very large amount of air. The result is powerful deep bass output from a small enclosure with exceptional distortion performance and vast thermal power handling. All of this gives the Ultra 18 the ability to often perform on par with 2 lesser drivers in half the space. 

It is no surprise that the resultant sound that is produced is very high quality possessing smooth wide range response, loads of headroom, low distortion and little compression. These are pretty much the hallmarks of a great sounding bass system.