http://forum.hsuresearch.com/showthread.php?t=27188
As mentioned in the above thread, the former glory era of HSU cylinder subs may be returning!
I own a pair of the original TN1220HO tubes and may be a candidate for the "replacement killers"
1. Will the new TN's be passive?
2. Will they use the same bass optimizer?
3. Will there be an upgrade price or upgrade path to go from the old TN's?
4. How will the new TN's perform compared to the original TN's?