Several years ago I augmented a Sonicap Gen 1 with a leftover Audio Cap Theta behind the old silk tweeter from you and Danny. I think my values were a goofy mix. The Sonicap Gen 1 was perhaps a 4.6 and the Theta was a 5.1. I didn't really do any solid experimentation, but thought the Theta really smoothed the edges - perhaps too much in this application. The old silk tweeter from you and Danny was already pretty smooth and probably would have been better without the Audio Cap Theta augmentation. Nonetheless, the value worked so the augmented capacitor combination remained in the speaker.
In a very recent attempt to re-use some leftover capacitors to repair a Linn Speaker I again used Audio Cap Theta Augmentation. This time I really think it worked. On both crossover boards I removed the old electrolytic capacitors and replaced them with a mix of values in parallel getting to the correct ultimate value. For the tweeter I used a 6.2uf Sonicap Gen augmented with a 1uf Audio Cap theta. The factory caps were labeled 7.2uf and the schematic also indicated 7.2uf. I did NOT accomplish any exhaustive a/b testing, but I have a pretty good sense of what my tweeters sound like with a single sonicap Gen I. I think the Audio Cap Theta partners nicely in this manner.
I completely understand my approach to this is NOT scientific and may be objectively wrong. But... have you done something similar ? Am I on something
or on to something
Also, after digging into the project, the malfunction was NOT bad electrolytic capacitors. There was cabinet peeled grunge on the binding post plate