Replacing EL caps in PSB crossover

[TDWesty]

My 1986 vintage PSB 70Rs still sound good, but I wonder if some new caps in the crossovers would improve things... they are 4.7uF and 8uF 100V non-polar EL. I can't find any NP EL caps above 50V in these sizes, but I can find both Polyprop and Polyester at digi-key (both Panasonic).
Is Polyester ok, or should I use polyprop at 3x price? The original cap is 8uF (not 8.2uF) a size which nobody seems to make. I assume since EL caps are not that accurate to start with, a 2.5% increase to 8.2 won't matter much?

I must admit exactly how a crossover behaves with different values is not something I can understand without some mental effort right now :-), so I'm not sure what to expect from now caps, assuming that the old ones have degraded to a value somewhat lower than their rating.

[roddyama]

If "EL" means electrolytic than yes, replacing them with polypropylene's should provide some sonic improvements. This would be particularly true if the cap is in series with the driver. Be sure the new caps are of equal or higher voltage rating. +/- a few % of the original rated capacitance value would be fine but if you go to one of the online speaker component providers, you should be able to find both values you've mentioned.

[TDWesty]

Yes, they are non-polarized electrolytics - I don't know the crossover details yet, as I haven't pulled them out of the cabinets (they are my main listening speakers). Thanks for the info; I will add some poly caps to my next parts order, and then do an A-B comparison of old & new.

Are polypropylene considered significantly better than polyester in this application?

[roddyama]

Originally posted by TDWesty
Are polypropylene considered significantly better than polyester in this application?

Yes, they are considered better by most. Would the extra cost IMO.