Charles1dad, You said you replaced your speaker caps with CAST. What speaker caps did you replace? Your cost of $850 for the pair of speaker caps suggests that it's a rather small value. Did you replace the full cap or are you using the CAST as a bypass? What cap was in the speaker before the replacement?
Sorry for all the questions but I am trying to determine the most cost effective approach for my own speakers. I need both a 7.5uf and 3.0uf for my high-pass crossover, and the low-pass uses a 5.6uf. Trying to do all those with CAST would be very expensive. I recently hooked up a brand new 1uf CAST in parallel with the 7.5uf and I was really quite surprised by the magnitude of improvement. That has me thinking of using smaller CAST caps just as bypass caps.