I'm very pleased with the performance of the upgraded crossover components. It has greatly improved the high frequency response; itís not as shrill as with the factory components. On the low end, the speakers are much faster. The percussive notes are sharper and the snap of the snare drum is better defined as with all the bass transients. Overall the sound stage is better, each instrument is more distinctive, everything is much more life like.
As for the crossover construction I had to parallel a 1.5 uF Solen with a .22 uF Dayton to for the 1.75 uF cap to match Klipsch crossover schematic. I did try to reverse engineer the crossover design with out any success. I couldn't figure out how Klipsch came up with the crossover frequency of 2800 Hz.
I did price the crossovers using Hoveland Speaker Caps, but it would have doubled the price with just the caps alone. I don't have much money in these speakers and didn't want to invest much more than the $60 I spent. However, the money was well worth the improvements.
After disassembling the SF2's, I'm impressed with the build quality of these speakers. They are very well designed and the build quality is very good for a manufactured speaker. I like the simplicity of the two way crossover design and not having to worry about the phasing shifting of a three way design. The parallel woofers with a two way crossover design is an elegant solution.
I've tried my SF2's with a sub, but still prefer them by themselves for stereo listening. Their low end is quite good when driven by my SC150 tube amp or a good solid state amp.