Are speaker cable connectors THAT important?

Are you sure they are aluminun? they could be silver plated copper.

I don't think that either gold or silver on the surface will make anything sound better. Another layer of metal is all that is in the way of the music. However, the gold or silver can reduce corrosion which is a plus. I prefer Rhodium over copper or just pure copper. The above post to use Cardas posts is good advice. The 4-pin XLR is probably because you have 4 wires internally 2-pos, 2-neg or returns and a bi-wire set of binding posts would be a great option for you. Michael Percy Audio has Cardas, WBT, Vampire choices worth looking at. You better know how to solder and how to drill out the post holes because it can be a bit involved. The Cardas posts use so much metal that if you have a cheesy Radio Shack soldering iron, you can wait for a long time before solder is hot enough to melt. Use the Cardas solder...low melt point and 4% silver. Jeff

Is it possible to replace the speaker connector with something more traditional such as Cardas three way binding posts?

This would sure open up a world of options.