Just a thought.. because your speakers/sub are from a previous "era", try connecting them like they were likely designed to be used: i.e. does the subwoofer amp have speaker-level inputs/outputs? If so, have you tried using them? If this sub/amp/crossover system was designed and sold pre-Dolby Digital/DTS, it may actually sound better if you feed the subwoofer amp a full-range speaker-level signal and let the Kinergetics amp/crossover do it's thing. I gather from other posts here that your system offers a high degree of adjustability in this regard to get a seamless blend between the Satellites (Spicas) and sub.
If you want to try this, you'll have to set your receiver's bass-management properly. Set it for front speakers "large" and subwoofer "no". Set your center channel and surrounds to "small" if you have them. Setup this way, all LFE will get routed to your subs via the front L-R speaker cables and your Spicas should be protected from low bass by the crossover in the Kinergetics amp.
Do not use the line-level output from your receiver's "subwoofer out". Run your front L-R speaker cables from your receiver to the Kinergetics' speaker-level input and then connect your Spicas to the subwoofer amps' speaker-level output. Of course, disregard this if the subwoofer amp lacks speaker-level connections, but I'd be suprised if it didn't as this system was apparently engineered for high-end two-channel music and most two channel pre-amps of that era would not likeley have included a line-level "sub-out" like a modern DD/DTS-era receiver/processor.
Let me know if your system sounds any better set up this way.
JZ
