I love this thread ...so many memories brought back to life. Anyone have the Yamaha NS-1000's back in the day ? The only vintage gear I have left (not sold or blown up) is a set of '89 JBL LX 44's an '82 M&K Goliath passive sub and a See Corp Revolver TT ( '82 vintage). I did have a set of Alnico Electrovoice 12 inchers (with whizzer cones) hooked up to a heath kit EL84 tube amp my dad built in '73 (all long gone)...the speakers came from a console of late 50's vintage...the combination although restricted in freq range sounded amazing at low volume but fell apart when cranked a bit. I built my own speakers throughout the 70's and used them for a number of years before getting a set of StudioLAB's (model number escapes me) amped by an SAE preamp and amp combo (late 70's vintage picked up from a pawn shop for peanuts).
Sky I bet a complete xover overhaul would really blow your mind with those lovely Pioneer speaks....it's highly likely the caps and resistors are out of spec...the inductors are likely quite inferior to today's Air core or foil types. It would certainly be a worthwhile investment. I bet those speakers would compete quite well with your main setup once reworked with the updated/upgraded xovers.
Peete.