I just recapped a pair of Acoustic Research AR58S speakers. A 3-way, with a 3/4" dome tweeter, a 1.5" dome mid, and a 12" woofer. Very nice, detailed and dynamic speakers. Much better than I expected. And for a 12" woofer, it blends exceptionally well with the dome mid.
For the recap, I cheaped out a bit. I used Bennic NPE's, with Dayton Film & Foil bypass caps, for the parallel shunts. For the series caps, I used a 3.9uF CSA Clarity Cap (with a Dayton 0.1 F&F, for the 4.0uF value) needed for the tweeter, and a 25 ESA Clarity for the dome mid. No bypass there (yet), as I wanted to hear them stock, as-is.
On first listen, the caps were very closed in, no air. Poor dispersion. The music was very localized to the speaker cabinets. Good low level detail. Foley effects, in movies, were very audible. But, oddly enough, the mids were quite veiled, with poor upper end response. Very closed in, as stated. What I was hearing was pretty much how Tony Gee described the ESA's as sounding on his Humble Homemade HiFi review. Maybe too warm and relaxed for me?
After a few hours of play, the speakers bloomed a bit more. The music became much more expansive. Though still, after about 40 hours, the Clarity Caps are still veiled and closed in to me. I hope additional break in helps? It might soon be time to add a bypass to the 25uF mid cap. If after a few more weeks, and the sound doesn't improve, it'll be time for another Mundorf order from Jeff. Match the AR58S speakers, to my AR90's!