Jim,
You are on the right track removing all obstacles in the signal path especially at the speaker level. I congratulate you for your efforts. Often too much time and money is spent on cables that terminate into the thin internal wire, the coils and capacitors that reside in a speaker crossover. Make no mistake here, the capacitors, inductors and resistors in a speaker crossover, no matter how expensive, are better eliminated. One should realize that anything going on at the speaker level involves many volts and many amps. At 100 watts, an 8 ohm speaker passes 5 amps at 40 volts. On the other hand, if the same filtering is done at the line level, currents are less than a milliamp (1/1000 amp) and barely a volt.
You are also right about soldering the wires to the driver terminals directly. Push-on connectors should be banned from all serious speaker designs. Too many enthusiasts are all to concerned about what they can see on the outside and tend to be uninterested about what is going on inside where they cannot see it.
Quite frankly I think any consciences speaker designer selling a product at several thousand dollars is selling his customer short by not doing things the right way. Gold binding posts, fancy wire, caps with fancy pedigrees are no match for multi-amping and crossing over or filtering before the amps. The amps are happier, the drivers are happier, the wires have less demanding work to do, everything is better. In many cases the saving in these speaker level crossovers could go a long way toward buying the second amplifier. Think of the advantages of each driver having the right kind of amplifier. Tubes for midrange, solid state for bass, what's your pleasure. Why have 100 watts that the woofer needs supplied to a tweeter that only needs a few watts. How many tweeters are padded down to match the woofer's lower sensitivity. Those drivers are so different, they should be treated separately? In addition the level controls on the crossover allow the listener to tailor the response to his taste and room conditions. Having done this for years in my own system, I wouldn't want to be without this flexibility.
To your specific needs both the top and bottom ends can be handled at line level before the power amp. It can all be done with a few resistors and capacitors that will carry no significant current. This is an important point. All those glorious claims of oil, Teflon, poly this and poly that have little meaning when the voltage and current are removed from the application.
I welcome questions from those who would care to apply these ideas to their speaker/amplifier systems.