Found this on hifiengine.
Description
The ESS AMT 1 Tower, though quite dissimilar in appearance from the AMT 1, is a high performance luxury version of that speaker and extracts every bit of low range potential in the AMT 1 woofer by utilizing a considerably larger and more complex enclosure.
It incorporates the same woofer and ESS Heil air-motion transformer as the smaller speaker but differs in its capability for sustaining extended low frequency response. It, therefore, substantially increases low frequency output for applications where performance can outweigh convenience as a deciding factor.
The AMT 1 Tower's deep bass performance is obtained through the use of a full 6 foot quarter wave length transmission line, the result of long experience by ESS in the design and construction of folded transmission line labyrinths.
Employing techniques perfected in the earlier and highly acclaimed ESS Transtatic and Translinear models, ESS developed a new, resistively loaded transmission line precisely matched to requirements of the AMT 1 woofer that provides the AMT 1 Tower with deep, full-bodied bass descending to 30 Hz pedal tones.
With this high pressure bass seamlessly matched to the open detailed midrange and clear pure highs that only the ESS Heil air-motion transformer can achieve, it is a perfectionist's high performance system capable of accurately reproducing all the information on today's finest recordings.
A large floor standing system, the AMT 1 tower is styled with lines of elegant restraint that blend into without dominating any decor. It's top surface is structurally sound, allowing it to be used as a display pedestal if desired.
Combined with this sturdy attractive column is the heritage of ESS transmission line design, now integrated with the unapproachable accuracy of the revolutionary ESS Heil air-motion transformer to create a new tradition of excellence.
So it should use the same woofer. Btw, I’ve seen two versions of the woofers. One with the alnico magnet, the other with a much smaller and lighter magnet. Seen both on two sets of pairs.
