upgrading speaker crossovers


I have a pair of PSB Stratus Gold'is and I am thinking of upgrading the crossovers, I am going to try this before I think about buying new speakers., which are in the area of $10000. The crossover in a speaker consists of 1-2.5mf 440vac film and 1- 6mf 440vac film by RC. then I have 4 100mf 100vac electrolytics. Why are the elecrolytics there, is this because of cost? I would much rather put in polys in their place, which will cost me $30.00 each. So my question is are the elecrolytics there because of cost issues if so can I change them to ploys?

My equipment consists of conrad johnson PV14l tubed preamp and a conrad johnson MF2500 amp. Both are right now at cj to be upgraded, the preamp is also getting teflon caps. I also have a pair of Mirage M1;s that I have upgraded with SI tweeters and Woofers. Must have gotten the last ones from them because now they will not even talk to you about the speaker when you call.

Anyway any advise on upgrading the crossovers would be greatly appreciated.
jchristilles
If there is a discount to be had by ordering more, I would be willing to join you in purchasing the caps for my Golds. I assume they are the same as the Goldi as only the cabinets and port were changed.
The crossover parts may have been selected not just on cost but how they effect overall sound quality. Blindly upgrading crossover networks without understanding how they function or why certain parts where chosen,just with the thinking that if I replace with more costly parts performance will increase is very wrong thinking. But all who do always hear a improvement and that alone I would question. They also rarely if ever compare stock to modified so its just they I changed it it now sounds better to me. So upgrading crossover networks is mostly a waist of time and money unless you really understand how they function and why designer chose what they did.
I would assume that a designer chooses a certain value for a crossover component and then finds a part that matches that value. Each part has a tolerance. I assume the better parts have a closer tolerance and that the specified value is closer to the actual value than a cheaper part, on the average. Of course, tolerance means variance, so it is possible that the cheaper part could be closer in value to the design value than the more expensive part.

But then, I also assume that the more expensive part will provide a better sound experience, and here is where I think we go wrong. Why should it? What is it about an electrolitic cap that makes it sound a certain way? I dont know and maybe someone can explain that.
I was going to replace my capacitors with the same value just a different cap. There are electrolytics in there and I wanted to replace them with film caps. And if nothing else replace the 2 film caps, on the crossover with better quality same value.
Just got my conrad johnson gear back a few weeks ago. I had the mf2500 upgraded to the "A" version and the pv14l to the series 2 edition along with teflon cap upgrade. It is basically new equipment. I have just ordered Mundorf caps to replace the film caps on the Gold I crossovers and I am going to give that a shot first. After I will decide if I am going to replace the electrolytic caps. I was also thinking of replacing the tweeter but not sure yet.

If all goes right I might actually sell my mirage M1's that have upgraded SI dirvers in them from the tweeters to the woofers.