Hi drbond, thanks for the question...
This servo sub replaced 2 $900ea Paradigm "Cube" - 10" subwoofers in this small dedicated studio: Rythmik L12 - sealed HT sub (rythmikaudio.com)
Texas to Maine was $629 delivered. This upgrade was months ago and I am still startled on occasion by its speed, depth (room responds slightly to 20Hz test tone!) and superb musicality overall...improving all frequencies...yes, research the importance of an accurate deep bass foundation in audio.
A long-time friend who made his first visit from Massachusetts recently was appropriately wowed. He has focused on subwoofers and their design for decades, including DIY. More info can be found in my posts. The choice for the Rythmik came after much research and the advice of two channel, seasoned, music lovers. Mare on the topic can be found in my posts. Onwards! More Peace Pin (bold print for old eyes)