(((This would work just fine unless I am missing something.)))
MoJo
Do you have a voltmeter can easily confirm If lyngdorf could work?
Download Vandertones under resources at the Vandersteen website
Set up the x over for - 3db at 80
Play Vandertones track 27= 1000 HZ adjust main volume control to read 1V AC next
Play Vandertones track 31= 100 HZ
Let me know what the Volt meter reads.
Best
JohnnyR